Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents

This Article Abstract Full Text (PDF, 261K) PPT slides of all figures Alert me when this article is cited Citation Map Services Email this article Similar articles in this journal Similar articles in PubMed Alert me to new content in the JEM Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Qian, D. Articles by Weiss, A. Search for Related Content PubMed PubMed Citation Articles by Qian, D. Articles by Weiss, A. Social Bookmarking                            What's this?

Article

Dapeng Qian^*, Sima Lev, Nicolai S.C. van Oers^*, Ivan Dikic, Joseph Schlessinger, and Arthur Weiss^*

From the ^* Howard Hughes Medical Institute, Departments of Medicine and of Microbiology and Immunology, University of California, San Francisco, California 94143; SUGEN, Redwood City, California 94063; and the Department of Pharmacology, New York University Medical Center, New York 10016

	Abstract

Top Abstract Materials and Methods Results and Discussion References

 
The Src family protein tyrosine kinases (PTKs), Lck and Fyn, are coexpressed in T cells and perform crucial functions involved in the initiation of T cell antigen receptor (TCR) signal transduction. However, the mechanisms by which Lck and Fyn regulate TCR signaling are still not completely understood. One important question is whether Lck and Fyn have specific targets or only provide functional redundancy during TCR signaling. We have previously shown that Lck plays a major role in the tyrosine phosphorylation of the TCR- chain and the ZAP-70 PTK. In an effort to identify the targets that are specifically regulated by Fyn, we have studied the tyrosine phosphorylation of Pyk2, a recently discovered new member of the focal adhesion kinase family PTK. We demonstrated that Pyk2 was rapidly tyrosine phosphorylated following TCR stimulation. TCR-induced tyrosine phosphorylation of Pyk2 was selectively dependent on Fyn but not Lck. Moreover, in heterologous COS-7 cells, coexpression of Pyk2 with Fyn but not Lck resulted in substantial increases in Pyk2 tyrosine phosphorylation. The selective regulation of Pyk2 tyrosine phosphorylation by Fyn in vivo correlated with the preferential phosphorylation of Pyk2 by Fyn in vitro. Our results demonstrate that Pyk2 is a specific target regulated by Fyn during TCR signaling.

Engagement of the TCR evokes a series of signal transduction events critical for the functional activation of T cells (reviewed in reference 1). Signal transduction through the TCR is also important for T cell development (1). The earliest detectable signaling event after TCR stimulation is the activation of protein tyrosine kinases (PTKs)¹, resulting in the tyrosine phosphorylation of cellular proteins (1). Lck and Fyn, two cytoplasmic PTKs of the Src family, have been implicated as the initiating PTKs for TCR signaling. Lck is critical for TCR signaling. Mutant T cell lines lacking functional Lck or T cells from lck^–/– mice respond to TCR stimulation with very limited tyrosine phosphorylation of cellular proteins, greatly decreased calcium mobilization, and reduced proliferation (2–4). Lck also plays a critical role in T cell development, as lck^–/– mice have a pronounced reduction in thymocyte numbers and a block in thymocyte development at the early CD4⁺CD8⁺ stage (2). The residual progression of thymocytes from CD4^–CD8^– to CD4⁺CD8⁺ stage in lck^–/– mice depends upon the redundant function of Fyn. Combined disruption of both Lck and Fyn (lck^–/–/fyn^–/–) completely arrests thymocyte development at the CD4^–CD8^– stage (5, 6). Fyn is also important for TCR signaling. Mature CD4⁺ and CD8⁺ thymocytes from fyn^–/– mice are severely impaired in TCR signaling as measured by calcium mobilization, protein tyrosine phosphorylation, IL-2 production, and proliferation (7, 8). Peripheral T cells from fyn^–/– mice are also impaired in TCR signaling, albeit to a lesser degree (7, 8).

The mechanisms by which Lck or Fyn regulates proximal TCR signaling are still not completely understood. One important issue is whether Lck and Fyn have specific targets or only provide functional redundancy during TCR signaling. We have studied the TCR signaling pathway in T cells from lck^–/– or fyn^–/– mice in an attempt to identify targets for Lck and Fyn. We have shown previously that Lck is the primary PTK that regulates the tyrosine phosphorylation of the TCR subunits and of ZAP-70 (9), a Syk family PTK critical for TCR signaling (reviewed in reference 10). The identity of the downstream target(s) for Fyn has not been identified. In the present study, we have focused our efforts in identifying target(s) whose phosphorylation is specifically regulated by Fyn. Previous studies have shown that Fyn interacts with a number of proteins in T cells (11–16), including several proteins migrating from 110 to 130 kD. These proteins are potential targets for Fyn, though their identities have not been fully elucidated. A recently discovered cytoplasmic PTK Pyk2 has a molecular mass of 112 kD (17–19). Pyk2 is a member of the focal adhesion kinase (FAK) family and has been shown to play important roles in signal transduction of neuronal cells (17, 20, 21). Because Pyk2 is also expressed in T cells (18, 19), we examined whether it might be a target for Fyn during TCR signaling. Our data demonstrate that Pyk2 is a novel Fyndependent tyrosine-phosphorylated substrate during TCR signaling.

	Materials and Methods

Top Abstract Materials and Methods Results and Discussion References

 
Mice.
Wild-type mice (C57BL/6 strain) were purchased from The Jackson Laboratory (Bar Harbor, ME). lck^–/– mice (2) and fyn^–/– mice (7) were obtained from Drs. T. Mak (Amgen and the Ontario Cancer Institute, Toronto, Ontario, Canada) and R. Perlmutter (University of Washington, Seattle, WA), respectively.

Cells.
Preparation of thymocytes and lymph node T cells were carried out as described (9). Jurkat, the human leukemic T cell line, was described previously (3). COS-7 cells (derived from monkey kidney), which do not express Lck, Fyn (T), ZAP-70, and Pyk2 endogenously, have been described (22). TAg Jurkat cells, obtained from Dr. G. Crabtree (Stanford University, Palo Alto, CA), are Jurkat T cells stably transfected with SV40 TAg.

Antibodies.
Anti-CD3 mAb 145-2C11 was obtained from the American Type Culture Collection ([ATCC] Rockville, MD). C305 is an anti-TCR mAb. The anti–ZAP-70 mAb 2F3 was described (22). The rabbit anti–ZAP-70 antiserum no. 1598 and the anti–ZAP-70 mAb 1E7.2 were produced against a KLH–peptide immunogen with a peptide corresponding to the human ZAP-70 amino acid sequence 282–307. Antibodies against Pyk2 were raised in rabbits immunized against a synthetic peptide corresponding to 15 amino-terminal residues (D1) (17) or with GST fusion protein containing amino acids 362–647 (antibody nos. 1 and 3) (17) or 679–830 (antibody no. 600) (21) of Pyk2. The rabbit anti-Fyn antibody and the anti-Lck mAb 1F6 were obtained from Drs. A. Veillette (McGill University, Montreal, Canada) and J. Bolen (DNAX Research Institute, Palo Alto, CA), respectively. The rabbit anti-Lck antibody was generated using a TrpE fusion protein containing the amino-terminal unique region of Lck as an immunogen. The anti-Fyn mAb was obtained from Transduction Laboratories, Lexington, KY. 12CA5 (Boehringer Mannheim, Indianapolis, IN) is a murine mAb to the hemagglutinin (HA) epitope. OKT8, obtained from ATCC, is a murine mAb to the CD8- chain. Anti-phosphotyrosine mAbs 4G10 and RC20 were obtained from Upstate Biotechnology, Lake Placid, NY and Transduction Laboratories, respectively.

Plasmids.
Lck and Fyn (T) were expressed with the pSM vector and pSV7d vector, respectively, as described (22). pSM was derived from pSV7d. Pyk2 and PKM, a kinase-inactive Pyk2 mutant, were expressed with the pRK5 vector (17, 20). ZAP-70 (K369A) was expressed with the pBJ1 vector (23). HA–Pyk2 was created by fusing the HA-epitope tag (YPYDVPDYAS) to the carboxy-terminal end of Pyk2 and subcloned into pRK5 vector.

Stimulation, Solubilization, Immunoprecipitation, and Immunoblot Analysis.
Stimulation of mouse thymocytes and T cells with 10 µg/ml purified anti-CD3 mAb 145-2C11 was carried out as described (9). Stimulation of Jurkat with the anti-TCR mAb C305 or 1 µM ionomycin was performed as described (3). Cells were lysed in a buffer containing 1% NP-40, 10 mM Tris, pH 7.6, 150 mM NaCl, 2 mM EDTA, protease and phosphatase inhibitors, as described (3). Immunoprecipitation, immunoblotting, stripping, and reprobing blots were performed as described (23).

Transfections.
COS-7 cells were transiently transfected with 2 µg of each construct using DEAE–dextran (22). The total amount of DNA for each transfection was equalized with vector DNA. Cells were harvested 72 h after transfection and lysed with the lysis buffer as described above. Transient transfection of TAg Jurkat cells with 40 µg pRK5.HA–Pyk2 expression construct and stimulation of transfected cells were carried out as described (23).

Kinase Assays.
For in vitro kinase reactions using poly(Glu: Tyr) (4:1) as an exogenous substrate, immunoprecipitates were washed three times with the RIPA buffer (1% NP-40, 1% deoxylcholate, 0.1% SDS, 50 mM Tris, pH 7.6, 150 mM NaCl, 5 mM EDTA, and protease and phosphatase inhibitors), once with the RIPA buffer without EDTA, once with the kinase buffer I (50 mM Tris, pH 7.6, 5 mM MnCl₂, 5 mM MgCl₂), and incubated with 30 µl kinase buffer I containing 20 µg poly(Glu/Tyr) (4:1) (Sigma) and 10 µCi -[³²P]ATP (6,000 Ci mmol^–1; Amersham) for 12.5 min at room temperature. The reactions were stopped with SDS sample buffer and resolved on SDS-PAGE (10% gel). Autoradiography and quantitation of the kinase activity were performed as described (17). For in vitro kinase reactions using purified Lck or Fyn (Upstate Biotechnology, Lake Placid, NY), immunoprecipitates were washed three times with the RIPA buffer, once with the RIPA buffer without EDTA, once with the kinase buffer II (20 mM Hepes, pH 7.4, 100 mM NaCl, 5 mM MnCl₂, 5 mM MgCl₂), and incubated with 30 µl kinase buffer II containing 3 U purified kinase (1 U is defined as 1 pmol phosphate transferred to a cdc2 [6–20] peptide min^–1 mg protein^–1), 1 µM cold ATP, and 10 µCi -[³²P]ATP for 10 min at room temperature. The reactions were stopped with SDS sample buffer and resolved on SDSPAGE.

	Results and Discussion

Top Abstract Materials and Methods Results and Discussion References

 
Lck and Fyn Regulate the Tyrosine Phosphorylation of Shared and Distinct Substrates.
To determine whether Lck and Fyn have specific targets or only provide functional redundancy during TCR signaling, we first examined the induction of tyrosine-phosphorylated proteins after TCR stimulation in thymocytes isolated from wild-type, lck^–/–, or fyn^–/– mice (Fig. 1 A). TCR stimulation–induced tyrosine phosphorylation of cellular proteins was generally decreased in thymocytes isolated from either lck^–/– or fyn^–/– mice compared with those from wild-type mice. More importantly, reductions in tyrosine phosphorylation of different proteins were evident. These results suggest that Lck and Fyn regulate the tyrosine phosphorylation of shared and distinct substrates. We have already shown (9) and confirm here that Lck is the primary Src family PTK regulating the tyrosine phosphorylation of the TCR- chain and ZAP-70, whereas Fyn has only a minor redundant role in regulating these events (Fig. 1, A and B).

View larger version (34K): [in this window] [in a new window] [Download PPT slide]   Figure 1 (A) Lck and Fyn regulate TCR stimulation–induced tyrosine phosphorylation of shared and distinct substrates. Thymocytes isolated from wild-type (Wt), lck–/–, or fyn–/– mice were either left unstimulated (–) or stimulated (+) with the anti-CD3 mAb 145-2C11 for 3 min. Cells were lysed, and tyrosine phosphorylation of whole cell lysates was analyzed by immunoblotting with the anti-phosphotyrosine (anti–P-Tyr) mAb 4G10. The migration of tyrosine-phosphorylated TCR- chain is indicated. Molecular mass markers are also indicated. (B) Tyrosine phosphorylation of ZAP-70 requires Lck but not Fyn. Thymocytes isolated from wild-type (Wt), lck–/–, or fyn–/– mice were either left unstimulated or stimulated with the anti-CD3 mAb for 3 min. Cells were lysed, ZAP70 was immunoprecipitated (IP) with an anti–ZAP-70 mAb (1E7.2), and analyzed by anti–P-Tyr immunoblotting using mAb 4G10. The same blot was stripped and reprobed with anti–ZAP-70 (mAb 1E7.2).

 
Pyk2 Is a Novel Tyrosine-phosphorylated Substrate after TCR Stimulation.
To determine whether Pyk2 is a target for Fyn during TCR signaling, we first tested whether Pyk2 becomes tyrosine phosphorylated upon TCR stimulation. We found that Pyk2 was weakly tyrosine phosphorylated at basal state in T cells. Stimulation of the TCR resulted in a rapid increase in Pyk2 tyrosine phosphorylation in human Jurkat T cells (Fig. 2 A, left) or in normal mouse thymocytes and lymph node T cells (Fig. 2 B). Enhanced tyrosine phosphorylation of Pyk2 is relatively specific to TCR stimulation, as activation via Fas or the costimulator receptor CD28 did not lead to increased Pyk2 tyrosine phosphorylation (data not shown). Furthermore, in contrast with other systems, such as the nicotinic acetylcholine receptor expressed in neuronal cells, which induce Pyk2 tyrosine phosphorylation by stimulation of extracellular calcium influx (17, 20, 24), TCR-induced tyrosine phosphorylation of Pyk2 is Ca²⁺ independent. Treatment of Jurkat T cells (Fig. 2 A, right) or mouse thymocytes (data not shown) with the calcium ionophore, ionomycin, did not stimulate Pyk2 tyrosine phosphorylation. Moreover, EGTA had no effect on TCRstimulated Pyk2 tyrosine phosphorylation in these cells (data not shown). Thus, Pyk2 tyrosine phosphorylation is likely to be an event proximal to Ca²⁺ mobilization during TCR signaling. Together, these results demonstrate that Pyk2 is a newly identified physiological target of activated PTK(s) after TCR stimulation.

View larger version (21K): [in this window] [in a new window] [Download PPT slide]   Figure 2 Fyn, but not Lck, is required for TCR-stimulated Pyk2 tyrosine phosphorylation. (A) Pyk2 phosphorylation in Jurkat T cells. Left, Jurkat cells were stimulated with anti-TCR (mAb C305) for the indicated period of times. Right, Jurkat cells were stimulated with antiTCR or ionomycin (IONO) for 2 min. Cells were lysed, Pyk2 was immunoprecipitated with anti-Pyk2 (antibody no. 3), and analyzed by immunoblotting using anti–P-Tyr mAb RC20. The level of Pyk2 in each sample was verified either by immunoblotting an aliquot of anti-Pyk2 immunoprecipitates with antiPyk2 (antibody no. 3) (left) or by stripping and reprobing the same blot with anti-Pyk2 (right). (B) Thymocytes isolated from wildtype (Wt), lck–/–, or fyn–/– mice were either left unstimulated or stimulated with the anti-CD3 mAb for 3 min. Cells were lysed, Pyk2 was immunoprecipitated with anti-Pyk2 (antibody no. 600), and analyzed by immunoblotting using anti-P-Tyr mAb 4G10. The same blot was stripped and reprobed with antiPyk2 (antibody no. 3).

 
Tyrosine Phosphorylation of Pyk2 during TCR Signaling Is Fyn Dependent.
We compared the status of Pyk2 tyrosine phosphorylation in thymocytes and T cells isolated from lck^–/– or fyn^–/– mice with those from wild-type mice (Fig. 2 B). Because lck^–/– mice have few peripheral T cells, we focused our analysis on thymocytes. Pyk2 tyrosine phosphorylation was readily detected after TCR stimulation in thymocytes isolated from lck^–/– mice. In contrast, thymocytes and lymph node T cells from fyn^–/– mice exhibited little, if any, detectable basal and TCR-stimulated Pyk2 tyrosine phosphorylation. This experiment provides strong genetic evidence that Fyn, but not Lck, is required for tyrosine phosphorylation of Pyk2 during TCR signaling.

Selective Regulation of Pyk2 Tyrosine Phosphorylation and Activation by Fyn in COS-7 Cells.
Because it is possible that the differences in Pyk2 phosphorylation observed in lck^–/– and fyn^–/– thymocytes might reflect heterogeneity in the cellular subsets in these mice, the regulation of tyrosine phosphorylation of Pyk2 by Lck and Fyn was further studied in a heterologous cell system, COS-7 cells. Cotransfection of Pyk2 with the lymphocyte-specific form of Fyn, Fyn (T), resulted in a marked increase in Pyk2 tyrosine phosphorylation (Fig. 3 A, right). Hence, overexpression of Fyn (T) in the absence of other lymphoid-specific components in COS-7 cells is sufficient to induce Pyk2 tyrosine phosphorylation. Cotransfection with Lck only led to a slight increase in Pyk2 tyrosine phosphorylation. However, Lck induced substantial tyrosine phosphorylation of a kinase-inactive ZAP-70 mutant, ZAP-70 (K369A), even when expressed at a lower level (Fig. 3 A). Cotransfection of Pyk2 with Fyn (T), but not Lck, also enhanced the kinase activity of Pyk2 towards the exogenous substrate, poly (Glu/Tyr) (4:1) (Fig. 3 B). Mutation of the ATP-binding site in the kinase domain abolished the kinase activity of Pyk2 (Fig. 3 C, left), but had no effect on the overall tyrosine phosphorylation of Pyk2 induced by cotransfection with Fyn (T) (Fig. 3 C, right). Thus, the kinase activity of Pyk2 is not required for its tyrosine phosphorylation induced by Fyn (T) in these cotransfection experiments. Taken together, these results further demonstrate that Pyk2 tyrosine phosphorylation or activation is selectively regulated by Fyn, but not Lck.

View larger version (48K): [in this window] [in a new window] [Download PPT slide]   Figure 3 Pyk2 activation is selectively induced by Fyn, but not Lck. (A) Tyrosine phosphorylation of Pyk2. Pyk2 or the kinase-inactive ZAP-70 mutant, ZAP-70 (K369A), was transiently cotransfected with vector, Lck, or Fyn (T) into COS-7 cells. Tyrosine phosphorylation of Pyk2 or ZAP-70 (K369A) was determined by immunoblotting using anti–P-Tyr mAb 4G10 (right), after immunoprecipitation with anti-Pyk2 (antibody no. 1) or anti– ZAP-70 (antibody no. 1598). The expression of Pyk2, ZAP-70 (K369A), Fyn (T), or Lck in each transfected sample was determined by immunoblotting whole cell lysates with anti-Pyk2 (antibody no. 1), anti–ZAP-70 (mAb 2F3), a rabbit anti-Fyn antibody, or anti-Lck (mAb 1F6) (left). (B) Phosphorylation of an exogenous substrate by Pyk2. Pyk2 was transiently transfected into COS-7 cells with vector, Lck, or Fyn (T). Cells were lysed, and Pyk2 was immunoprecipitated with anti-Pyk2 (antibody no. 600). The immunoprecipitates were extensively washed with RIPA buffer, and subjected to kinase reactions in vitro in the presence of -[32P]ATP and the exogenous substrate poly(Glu/Tyr) (4:1). The phosphorylated products were resolved by SDS-PAGE, analyzed by autoradiography (top), and quantitated by a phosphorimager and Image Quant software (Molecular Dynamics). The kinase activities relative to vector cotransfected cells are indicated (middle). The expression of Pyk2 in each sample was determined by immunoblotting whole cell lysates with antiPyk2 (antibody no. 1) (bottom). (C) The kinase activity of Pyk2 is required for the ability of Pyk2 to phosphorylate an exogenous substrate but not Pyk2 tyrosine phosphorylation induced by Fyn (T). Pyk2 or the kinase inactive mutant Pyk2 with a point mutation at the ATP-binding site (PKM) was cotransfected with Fyn (T) into COS-7 cells. Cells were lysed, and Pyk2 or PKM was immunoprecipitated with anti-Pyk2 (antibody no. 600). Phosphorylation of poly(Glu/Tyr) (4:1) by the immunoprecipitates in in vitro kinase reactions was determined (left). The relative kinase activities to Pyk2 and vector cotransfected cells (data not shown) are also indicated. Tyrosine phosphorylation of Pyk2 and PKM was analyzed by immunoblotting using anti– P-Tyr mAb 4G10 (right). The expression of Pyk2, PKM, or Fyn (T) in each transfected sample was determined by immunoblotting whole cell lysates with the anti-Pyk2 (antibody no. 1) or an anti-Fyn mAb. (D) Phosphorylation of PKM by purified Lck or Fyn. COS-7 cells transfected with PKM were lysed, and lysates were immunoprecipitated with either normal rabbit serum (NRS) or an affinity-purified anti-Pyk2 (antibody D1). The immunoprecipitates were extensively washed with RIPA buffer and used in in vitro kinase reactions in the absence (–) or presence (+) of purified Lck or Fyn (3 U/reaction).

 
Pyk2 Is a Preferred Substrate for Fyn In Vitro.
The apparent differential regulation of Pyk2 tyrosine phosphorylation or activation by Lck and Fyn suggests that Pyk2 may be a preferred substrate for Fyn but not Lck. To determine whether Fyn or Lck could phosphorylate Pyk2, we immunoprecipitated the kinase-inactive Pyk2 mutant, PKM (17), that had been transfected into COS-7 cells and subjected it to kinase reactions in vitro with either purified Fyn or Lck (Fig. 3 D). When the same specific activities of Fyn and Lck were used in each reaction, PKM was strongly phosphorylated by Fyn. In contrast, little or no phosphorylation of PKM was induced by Lck. Thus, Pyk2 is a preferred substrate for Fyn in vitro.

Association of Pyk2 with Fyn and Lck in T Cells.
Next, we examined whether Fyn or Lck may interact with Pyk2 in T cells as determined by coimmunoprecipitation. Anti-Fyn antibodies coimmunoprecipitated comparable levels of Pyk2 from thymocytes of C57BL/6 mice before and after TCR stimulation (Fig. 4 A). However, anti-Pyk2 antibodies did not coimmunoprecipitate Fyn from mouse thymocytes (data not shown). This likely results from the disruption of association by antibody binding. To circumvent this problem, we introduced a HA tag into the carboxyl terminus of Pyk2 and then transfected the HA-tagged Pyk2 into TAg Jurkat T cells. Similar levels of Fyn were coimmunoprecipitated by anti-HA antibodies from HA–Pyk2-transfected TAg Jurkat cells before and after TCR stimulation (Fig. 4 B). These data indicate that Fyn constitutively associates with Pyk2 in T cells. Interestingly, anti-Lck antibodies also coimmunoprecipitated Pyk2 from mouse thymocytes before and after TCR stimulation (Fig. 4 A). This result is consistent with an association between Fyn and Lck that was reported previously (25). It is possible that Pyk2 is present in the same multimolecular complex containing both Fyn and Lck. However, because Pyk2 is a preferred substrate for Fyn, it is selectively phosphorylated or activated by Fyn, but not Lck.

View larger version (16K): [in this window] [in a new window] [Download PPT slide]   Figure 4 Physical association of Fyn with Pyk2 in T cells. (A) Thymocytes isolated from C57BL/6 mice were either left unstimulated or stimulated with the anti-CD3 mAb for 3 min. Cells were lysed, lysates were immunoprecipitated with NRS, a rabbit anti-Fyn antibody, or a rabbit anti-Lck antibody, and analyzed by immunoblotting with an affinitypurified anti-Pyk2 (antibody D1), an anti-Fyn mAb, and anti-Lck (mAb 1F6). (B) HA-tagged Pyk2 was transiently transfected into TAg Jurkat T cells. 40 h later, transfected cells were either left unstimulated or stimulated with anti-TCR (mAb C305) for 2 min. Cells were lysed, lysates were immunoprecipitated with either a control (Ctrl) antibody (OKT8) or antiHA (mAb 12CA5), and analyzed by immunoblotting with an anti-HA mAb (12CA5) and an anti-Fyn mAb. The positions of HA–Pyk2 and Fyn are indicated by arrows.

 
In summary, our results demonstrate that Pyk2 is selective target regulated by Fyn during TCR signaling. This selectivity is due, at least in part, to the fact that Pyk2 is a preferred substrate for Fyn in vitro. Also, these findings provide evidence that Lck and Fyn have functional specificities during TCR signaling. Activation of distinct targets by Lck and Fyn may allow for the differential control of downstream signaling pathways by the TCR. Alternatively, full activation of a critical downstream signaling component may require synergism between two distinct upstream activating pathways regulated by TCR Lck ZAP-70 and TCR Fyn Pyk2. The defective TCR signaling responses in lck^–/– and fyn^–/– mice may result, in part, from the failure of ZAP-70 and Pyk2 to be activated, respectively. Further identification of other targets for Lck and Fyn, as well as the targets for ZAP-70 and Pyk2, should help clarify how these cytoplasmic PTKs coordinately mediate TCR signaling.

	Acknowledgments

Submitted: 17 January 1997

¹Abbreviations used in this paper: FAK, focal adhesion kinase; PTK, protein tyrosine kinase; ZAP-70, -associated protein 70.

	References

Top Abstract Materials and Methods Results and Discussion References

 

1 Weiss A & Littman DR. Signal transduction by lymphocyte antigen receptors, Cell, 1994, 76, 263–274.[Medline]

2 Molina TJ, Kishihara K, Siderovski DP, van Ewijk W, Narendran A, Timms E, Wakeham A, Paige CJ, Hartmann K-U, Veillette A et al.. Profound block in thymocyte development in mice lacking p56lck, Nature (Lond), 1992, 357, 161–164.[Medline]

3 Straus D & Weiss A. Genetic evidence for the involvement of the Lck tyrosine kinase in signal transduction through the T cell antigen receptor, Cell, 1992, 70, 585–593.[Medline]

4 Karnitz L, Sutor SL, Torigoe T, Reed JC, Bell MP, McKean DJ, Leibson PJ & Abraham RT. Effects of p56lck deficiency on the growth and cytolytic effector function of an interleukin-2-dependent cytotoxic T-cell line, Mol Cell Biol, 1992, 12, 4521–4530.[Abstract/Free Full Text]

5 van Oers NSC, Lowin-Kropf B, Finlay D, Connolly K & Weiss A. β T cell development is abolished in mice lacking both Lck and Fyn protein tyrosine kinases, Immunity, 1996, 5, 429–436.[Medline]

6 Groves T, Smiley P, Cooke MP, Forbush K, Perlmutter RM & Guidos CJ. Fyn can partially substitute for Lck in T lymphocyte development, Immunity, 1996, 5, 417–428.[Medline]

7 Appleby MW, Gross JA, Cooke MP, Levin SD, Qian X & Perlmutter RM. Defective T cell receptor signaling in mice lacking the thymic isoform of p59^fyn, Cell, 1992, 70, 751–763.[Medline]

8 Stein PL, Lee H-M, Rich S & Soriano P. pp59^fynmutant mice display differential signaling in thymocytes and peripheral T cells, Cell, 1992, 70, 741–750.[Medline]

9 van Oers NSC, Killeen N & Weiss A. Lck regulates the tyrosine phosphorylation of the T cell receptor subunits and ZAP-70 in murine thymocytes, J Exp Med, 1996, 183, 1053–1062.[Abstract/Free Full Text]

10 Wange RL & Samelson LE. Complex complexes: signaling at the TCR, Immunity, 1996, 5, 197–205.[Medline]

11 da Silva AJ, Yamamoto M, Zalvan CH & Rudd CE. Engagement of the TCR/CD3 complex stimulates p59fyn(T) activity: detection of associated proteins at 72 and 120–130 kD, Mol Immunol, 1992, 29, 1417–1425.[Medline]

12 da Silva AJ, Janssen O & Rudd CE. T cell receptor zeta/CD3-p59fyn(T)-associated p120/130 binds to the SH2 domain of p59fyn(T), J Exp Med, 1993, 178, 2107–2113.[Abstract/Free Full Text]

13 Tsygankov AY, Broker BM, Fargnoli J, Ledbetter JA & Bolen JB. Activation of tyrosine kinase p60fyn following T cell antigen receptor cross-linking, J Biol Chem, 1992, 267, 18259–18262.[Abstract/Free Full Text]

14 Tsygankov AY, Spana C, Rowley RB, Penhallow RC, Burkhardt AL & Bolen JB. Activation-dependent tyrosine phosphorylation of Fyn-associated proteins in T lymphocytes, J Biol Chem, 1994, 269, 7792–7800.[Abstract/Free Full Text]

15 Tsygankov AY, Mahajan S, Fincke JE & Bolen JB. Specific association of tyrosine-phosphorylated c-Cbl with Fyn tyrosine kinase in T cells, J Biol Chem, 1996, 271, 27130–27137.[Abstract/Free Full Text]

16 Gajewski TF, Qian D, Fields P & Fitch FW. Anergic T-lymphocyte clones have altered inositol phosphate, calcium, and tyrosine kinase signaling pathways, Proc Natl Acad Sci USA, 1994, 91, 38–42.[Abstract/Free Full Text]

17 Lev S, Moreno H, Martinez R, Canoll P, Peles E, Musacchio JM, Plowman GD, Rudy B & Schlessinger J. Protein tyrosine kinase PYK2 involved Ca2+-induced regulation of ion channel and MAP kinase functions, Nature (Lond), 1995, 376, 737–745.[Medline]

18 Sasaki H, Nagura K, Ishino M, Tobioka H, Kotani K & Sasaki T. Cloning and characterization of cell adhesion kinase β, a novel protein–tyrosine kinase of the focal adhesion kinase subfamily, J Biol Chem, 1995, 270, 21206–21219.[Abstract/Free Full Text]

19 Avraham S, London R, Fu Y, Ota S, Hiregowdara D, Li J, Jiang S, Pasztor LM, White RA, Groopman JE & Avraham H. Identification and characterization of a novel related adhesion focal tyrosine kinase (RAFTK) from megakaryocytes and brain, J Biol Chem, 1995, 270, 27742–27751.[Abstract/Free Full Text]

20 Tokiwa G, Dikic I, Lev S & Schlessinger J. Activation of Pyk2 by stress signals and coupling with JNK signaling pathway, Science (Wash DC), 1996, 273, 792–794.[Abstract]

21 Dikic I, Tokiwa G, Lev S, Courtneidge SA & Schlessinger J. A role for Pyk2 and Src in linking G-protein-coupled receptors with MAP kinase activation, Nature (Lond), 1996, 383, 547–550.[Medline]

22 Iwashima M, Irving BA, van Oers NSC, Chan AC & Weiss A. Sequential interactions of the TCR with two distinct cytoplasmic tyrosine kinases, Science (Wash DC), 1994, 263, 1136–1139.[Abstract/Free Full Text]

23 Qian D, Mollenauer MN & Weiss A. Dominantnegative zeta-associated protein 70 inhibits T cell antigen receptor signaling, J Exp Med, 1996, 183, 611–620.[Abstract/Free Full Text]

24 Yu H, Li X, Marchetto GS, Dy R, Hunter D, Calvo B, Dawson TL, Wilm M, Anderegg RJ, Graves LM et al.. Activation of a Novel calcium-dependent protein-tyrosine kinase, J Biol Chem, 1996, 271, 29993–29998.[Abstract/Free Full Text]

25 Beyers AD, Spruyt LL & Williams AF. Molecular associations between the T-lymphocyte antigen receptor complex and the surface antigens CD2, CD4, or CD8 and CD5, Proc Natl Acad Sci USA, 1992, 89, 2945–2949.[Abstract/Free Full Text]

CiteULike

Complore

Connotea

Del.icio.us

Digg

Facebook

Reddit

Technorati

Twitter

This article has been cited by other articles:

• Wong, N. K. Y., Lai, J. C. Y., Birkenhead, D., Shaw, A. S., Johnson, P. (2008). CD45 Down-Regulates Lck-Mediated CD44 Signaling and Modulates Actin Rearrangement in T Cells. J. Immunol. 181: 7033-7043 [Abstract] [Full Text]  
• Mamchak, A. A., Sullivan, B. M., Hou, B., Lee, L. M., Gilden, J. K., Krummel, M. F., Locksley, R. M., DeFranco, A. L. (2008). Normal Development and Activation but Altered Cytokine Production of Fyn-Deficient CD4+ T Cells. J. Immunol. 181: 5374-5385 [Abstract] [Full Text]  
• Anand, A. R., Cucchiarini, M., Terwilliger, E. F., Ganju, R. K. (2008). The Tyrosine Kinase Pyk2 Mediates Lipopolysaccharide-Induced IL-8 Expression in Human Endothelial Cells. J. Immunol. 180: 5636-5644 [Abstract] [Full Text]  
• Maksumova, L., Wang, Y., Wong, N. K. Y., Le, H. T., Pallen, C. J., Johnson, P. (2007). Differential Function of PTP{alpha} and PTP{alpha} Y789F in T Cells and Regulation of PTP{alpha} Phosphorylation at Tyr-789 by CD45. J. Biol. Chem. 282: 20925-20932 [Abstract] [Full Text]  
• Palacios, E. H., Weiss, A. (2007). Distinct roles for Syk and ZAP-70 during early thymocyte development. JEM 204: 1703-1715 [Abstract] [Full Text]  
• Bogin, Y., Ainey, C., Beach, D., Yablonski, D. (2007). SLP-76 mediates and maintains activation of the Tec family kinase ITK via the T cell antigen receptor-induced association between SLP-76 and ITK. Proc. Natl. Acad. Sci. USA 104: 6638-6643 [Abstract] [Full Text]  
• Martin-Cofreces, N. B., Sancho, D., Fernandez, E., Vicente-Manzanares, M., Gordon-Alonso, M., Montoya, M. C., Michel, F., Acuto, O., Alarcon, B., Sanchez-Madrid, F. (2006). Role of Fyn in the Rearrangement of Tubulin Cytoskeleton Induced through TCR. J. Immunol. 176: 4201-4207 [Abstract] [Full Text]  
• Finkelstein, L. D., Shimizu, Y., Schwartzberg, P. L. (2005). Tec Kinases Regulate TCR-Mediated Recruitment of Signaling Molecules and Integrin-Dependent Cell Adhesion. J. Immunol. 175: 5923-5930 [Abstract] [Full Text]  
• Butler, B., Blystone, S. D. (2005). Tyrosine Phosphorylation of {beta}3 Integrin Provides a Binding Site for Pyk2. J. Biol. Chem. 280: 14556-14562 [Abstract] [Full Text]  
• Aasheim, H.-C., Delabie, J., Finne, E. F. (2005). Ephrin-A1 binding to CD4+ T lymphocytes stimulates migration and induces tyrosine phosphorylation of PYK2. Blood 105: 2869-2876 [Abstract] [Full Text]  
• Paccani, S. R., Patrussi, L., Ulivieri, C., Masferrer, J. L., D'Elios, M. M., Baldari, C. T. (2005). Nonsteroidal anti-inflammatory drugs inhibit a Fyn-dependent pathway coupled to Rac and stress kinase activation in TCR signaling. Blood 105: 2042-2048 [Abstract] [Full Text]  
• Sugie, K., Jeon, M.-S., Grey, H. M. (2004). Activation of naive CD4 T cells by anti-CD3 reveals an important role for Fyn in Lck-mediated signaling. Proc. Natl. Acad. Sci. USA 101: 14859-14864 [Abstract] [Full Text]  
• Haglund, K., Ivankovic-Dikic, I., Shimokawa, N., Kruh, G. D., Dikic, I. (2004). Recruitment of Pyk2 and Cbl to lipid rafts mediates signals important for actin reorganization in growing neurites. J. Cell Sci. 117: 2557-2568 [Abstract] [Full Text]  
• Filipp, D., Leung, B. L., Zhang, J., Veillette, A., Julius, M. (2004). Enrichment of Lck in Lipid Rafts Regulates Colocalized Fyn Activation and the Initiation of Proximal Signals through TCR{alpha}{beta}. J. Immunol. 172: 4266-4274 [Abstract] [Full Text]  
• Gupta, S., Fanzo, J. C., Hu, C., Cox, D., Jang, S. Y., Lee, A. E., Greenberg, S., Pernis, A. B. (2003). T Cell Receptor Engagement Leads to the Recruitment of IBP, a Novel Guanine Nucleotide Exchange Factor, to the Immunological Synapse. J. Biol. Chem. 278: 43541-43549 [Abstract] [Full Text]  
• Okigaki, M., Davis, C., Falasca, M., Harroch, S., Felsenfeld, D. P., Sheetz, M. P., Schlessinger, J. (2003). Pyk2 regulates multiple signaling events crucial for macrophage morphology and migration. Proc. Natl. Acad. Sci. USA 100: 10740-10745 [Abstract] [Full Text]  
• Doucey, M.-A., Legler, D. F., Faroudi, M., Boucheron, N., Baumgaertner, P., Naeher, D., Cebecauer, M., Hudrisier, D., Ruegg, C., Palmer, E., Valitutti, S., Bron, C., Luescher, I. F. (2003). The {beta}1 and {beta}3 Integrins Promote T Cell Receptor-mediated Cytotoxic T Lymphocyte Activation. J. Biol. Chem. 278: 26983-26991 [Abstract] [Full Text]  
• Sancho, D., Montoya, M. C., Monjas, A., Gordon-Alonso, M., Katagiri, T., Gil, D., Tejedor, R., Alarcon, B., Sanchez-Madrid, F. (2002). TCR Engagement Induces Proline-Rich Tyrosine Kinase-2 (Pyk2) Translocation to the T Cell-APC Interface Independently of Pyk2 Activity and in an Immunoreceptor Tyrosine-Based Activation Motif-Mediated Fashion. J. Immunol. 169: 292-300 [Abstract] [Full Text]  
• Baker, J. E., Majeti, R., Tangye, S. G., Weiss, A. (2001). Protein Tyrosine Phosphatase CD148-Mediated Inhibition of T-Cell Receptor Signal Transduction Is Associated with Reduced LAT and Phospholipase C{gamma}1 Phosphorylation. Mol. Cell. Biol. 21: 2393-2403 [Abstract] [Full Text]  
• Huang, J., Tilly, D., Altman, A., Sugie, K., Grey, H. M. (2000). Inaugural Article: T-cell receptor antagonists induce Vav phosphorylation by selective activation of Fyn kinase. Proc. Natl. Acad. Sci. USA 97: 10923-10929 [Abstract] [Full Text]  
• Sancho, D., Nieto, M., Llano, M., Rodriguez-Fernandez, J. L., Tejedor, R., Avraham, S., Cabanas, C., Lopez-Botet, M., Sanchez-Madrid, F. (2000). The Tyrosine Kinase Pyk-2/Raftk Regulates Natural Killer (Nk) Cell Cytotoxic Response, and Is Translocated and Activated upon Specific Target Cell Recognition and Killing. JCB 149: 1249-1262 [Abstract] [Full Text]  
• Xiong, W., Macklem, M, Parsons, J. (2000). Expression and characterization of splice variants of PYK2, a focal adhesion kinase-related protein. J. Cell Sci. 111: 1981-1991 [Abstract]  
• Hazan-Halevy, I., Seger, R., Levy, R. (2000). The Requirement of Both Extracellular Regulated Kinase and p38 Mitogen-activated Protein Kinase for Stimulation of Cytosolic Phospholipase A2 Activity by Either Fcgamma RIIA or Fcgamma RIIIB in Human Neutrophils. A POSSIBLE ROLE FOR Pyk2 BUT NOT FOR THE Grb2-Sos-Shc COMPLEX. J. Biol. Chem. 275: 12416-12423 [Abstract] [Full Text]  
• Tang, H., Zhao, Z. J., Landon, E. J., Inagami, T. (2000). Regulation of Calcium-sensitive Tyrosine Kinase Pyk2 by Angiotensin II in Endothelial Cells. ROLES OF Yes TYROSINE KINASE AND TYROSINE PHOSPHATASE SHP-2. J. Biol. Chem. 275: 8389-8396 [Abstract] [Full Text]  
• Benbernou, N., Muegge, K., Durum, S. K. (2000). Interleukin (IL)-7 Induces Rapid Activation of Pyk2, Which Is Bound to Janus Kinase 1 and IL-7Ralpha. J. Biol. Chem. 275: 7060-7065 [Abstract] [Full Text]  
• Denny, M. F., Patai, B., Straus, D. B. (2000). Differential T-Cell Antigen Receptor Signaling Mediated by the Src Family Kinases Lck and Fyn. Mol. Cell. Biol. 20: 1426-1435 [Abstract] [Full Text]  
• Williams, L. M., Ridley, A. J. (2000). Lipopolysaccharide Induces Actin Reorganization and Tyrosine Phosphorylation of Pyk2 and Paxillin in Monocytes and Macrophages. J. Immunol. 164: 2028-2036 [Abstract] [Full Text]  
• Munshi, N., Groopman, J. E., Gill, P. S., Ganju, R. K. (2000). c-Src Mediates Mitogenic Signals and Associates with Cytoskeletal Proteins upon Vascular Endothelial Growth Factor Stimulation in Kaposi's Sarcoma Cells. J. Immunol. 164: 1169-1174 [Abstract] [Full Text]  
• Tsuchida, M., Manthei, E. R., Alam, T., Knechtle, S. J., Hamawy, M. M. (2000). Regulation of T Cell Receptor- and CD28-induced Tyrosine Phosphorylation of the Focal Adhesion Tyrosine Kinases Pyk2 and Fak by Protein Kinase C. A ROLE FOR PROTEIN TYROSINE PHOSPHATASES. J. Biol. Chem. 275: 1344-1350 [Abstract] [Full Text]  
• Tsuchida, M., Manthei, E. R., Alam, T., Knechtle, S. J., Hamawy, M. M. (1999). T Cell Activation Up-Regulates the Expression of the Focal Adhesion Kinase Pyk2: Opposing Roles for the Activation of Protein Kinase C and the Increase in Intracellular Ca2+. J. Immunol. 163: 6640-6650 [Abstract] [Full Text]  
• Munshi, N., Ganju, R. K., Avraham, S., Mesri, E. A., Groopman, J. E. (1999). Kaposi's Sarcoma-associated Herpesvirus-encoded G Protein-coupled Receptor Activation of c-Jun Amino-terminal Kinase/Stress-activated Protein Kinase and Lyn Kinase Is Mediated by Related Adhesion Focal Tyrosine Kinase/Proline-rich Tyrosine Kinase 2. J. Biol. Chem. 274: 31863-31867 [Abstract] [Full Text]  
• Nieto, M., Rodriguez-Fernandez, J. L., Navarro, F., Sancho, D., Frade, J. M.R., Mellado, M., Martinez-A, C., Cabanas, C., Sanchez-Madrid, F. (1999). Signaling Through CD43 Induces Natural Killer Cell Activation, Chemokine Release, and PYK-2 Activation. Blood 94: 2767-2777 [Abstract] [Full Text]  
• Raab, M., Kang, H., da Silva, A., Zhu, X., Rudd, C. E. (1999). FYN-T-FYB-SLP-76 Interactions Define a T-cell Receptor zeta /CD3-mediated Tyrosine Phosphorylation Pathway That Up-regulates Interleukin 2 Transcription in T-cells. J. Biol. Chem. 274: 21170-21179 [Abstract] [Full Text]  
• Lang, V., Semichon, M., Michel, F., Brossard, C., Gary-Gouy, H., Bismuth, G. (1999). Fyn Membrane Localization Is Necessary to Induce the Constitutive Tyrosine Phosphorylation of Sam68 in the Nucleus of T Lymphocytes. J. Immunol. 162: 7224-7232 [Abstract] [Full Text]  
• Blaukat, A., Ivankovic-Dikic, I., Gronroos, E., Dolfi, F., Tokiwa, G., Vuori, K., Dikic, I. (1999). Adaptor Proteins Grb2 and Crk Couple Pyk2 with Activation of Specific Mitogen-activated Protein Kinase Cascades. J. Biol. Chem. 274: 14893-14901 [Abstract] [Full Text]  
• She, J., Ruzek, M. C., Velupillai, P., de Aos, I., Wang, B., Harn, D. A., Sancho, J., Biron, C. A., Terhorst, C. (1999). Generation of antigen-specific cytotoxic T lymphocytes and regulation of cytokine production takes place in the absence of CD3{zeta}. Int Immunol 11: 845-857 [Abstract] [Full Text]  
• Li, X., Dy, R. C., Cance, W. G., Graves, L. M., Earp, H. S. (1999). Interactions between Two Cytoskeleton-associated Tyrosine Kinases: Calcium-dependent Tyrosine Kinase and Focal Adhesion Tyrosine Kinase. J. Biol. Chem. 274: 8917-8924 [Abstract] [Full Text]  
• Tsuchida, M., Knechtle, S. J., Hamawy, M. M. (1999). CD28 Ligation Induces Tyrosine Phosphorylation of Pyk2 but Not Fak in Jurkat T Cells. J. Biol. Chem. 274: 6735-6740 [Abstract] [Full Text]  
• Lev, S., Hernandez, J., Martinez, R., Chen, A., Plowman, G., Schlessinger, J. (1999). Identification of a Novel Family of Targets of PYK2 Related to Drosophila Retinal Degeneration B (rdgB) Protein. Mol. Cell. Biol. 19: 2278-2288 [Abstract] [Full Text]  
• Banu, Y., Watanabe, T. (1999). Augmentation of Antigen Receptor-mediated Responses by Histamine H1 Receptor Signaling. JEM 189: 673-682 [Abstract] [Full Text]  
• al-Ramadi, B. K., Zhang, H., Bothwell, A. L. M. (1998). Cell-cycle arrest and apoptosis hypersusceptibility as a consequence of Lck deficiency in nontransformed T lymphocytes. Proc. Natl. Acad. Sci. USA 95: 12498-12503 [Abstract] [Full Text]  
• Sunder-Plassmann, R., Reinherz, E. L. (1998). A p56lck-independent Pathway of CD2 Signaling Involves Jun Kinase. J. Biol. Chem. 273: 24249-24257 [Abstract] [Full Text]  
• Lin, H., Hutchcroft, J. E., Andoniou, C. E., Kamoun, M., Band, H., Bierer, B. E. (1998). Association of p59fyn with the T Lymphocyte Costimulatory Receptor CD2. BINDING OF THE Fyn Src HOMOLOGY (SH) 3 DOMAIN IS REGULATED BY THE Fyn SH2 DOMAIN. J. Biol. Chem. 273: 19914-19921 [Abstract] [Full Text]  
• Dikic, I., Dikic, I., Schlessinger, J. (1998). Identification of a New Pyk2 Isoform Implicated in Chemokine and Antigen Receptor Signaling. J. Biol. Chem. 273: 14301-14308 [Abstract] [Full Text]  
• Li, X., Hunter, D., Morris, J., Haskill, J. S., Earp, H. S. (1998). A Calcium-dependent Tyrosine Kinase Splice Variant in Human Monocytes. ACTIVATION BY A TWO-STAGE PROCESS INVOLVING ADHERENCE AND A SUBSEQUENT INTRACELLULAR SIGNAL. J. Biol. Chem. 273: 9361-9364 [Abstract] [Full Text]  
• Miyazaki, T., Takaoka, A., Nogueira, L., Dikic, I., Fujii, H., Tsujino, S., Mitani, Y., Maeda, M., Schlessinger, J., Taniguchi, T. (1998). Pyk2 is a downstream mediator of the IL-2 receptor-coupled Jak signaling pathway. Genes Dev. 12: 770-775 [Abstract] [Full Text]  
• Majeti, R., Bilwes, A. M., Noel, J. P., Hunter, T., Weiss, A. (1998). Dimerization-Induced Inhibition of Receptor Protein Tyrosine Phosphatase Function Through an Inhibitory Wedge. Science 279: 88-91 [Abstract] [Full Text]  
• van Oers, N. S. C., Love, P. E., Shores, E. W., Weiss, A. (1998). Regulation of TCR Signal Transduction in Murine Thymocytes by Multiple TCR {zeta}-Chain Signaling Motifs. J. Immunol. 160: 163-170 [Abstract] [Full Text]  
• Okazaki, H., Zhang, J., Hamawy, M. M., Siraganian, R. P. (1997). Activation of Protein-tyrosine Kinase Pyk2 Is Downstream of Syk in Fcepsilon RI Signaling. J. Biol. Chem. 272: 32443-32447 [Abstract] [Full Text]  
• Liao, X. C., Littman, D. R., Weiss, A. (1997). Itk and Fyn Make Independent Contributions to T Cell Activation. JEM 186: 2069-2073 [Abstract] [Full Text]  
• da Silva, A. J., Li, Z., de Vera, C., Canto, E., Findell, P., Rudd, C. E. (1997). Cloning of a novel T-cell protein FYB that binds FYN and SH2-domain-containing leukocyte protein 76 and modulates interleukin 2 production. Proc. Natl. Acad. Sci. USA 94: 7493-7498 [Abstract] [Full Text]  
• Ganju, R. K., Brubaker, S. A., Chernock, R. D., Avraham, S., Groopman, J. E. (2000). beta -Chemokine Receptor CCR5 Signals through SHP1, SHP2, and Syk. J. Biol. Chem. 275: 17263-17268 [Abstract] [Full Text]  
• Linseman, D. A., Heidenreich, K. A., Fisher, S. K. (2001). Stimulation of M3 Muscarinic Receptors Induces Phosphorylation of the Cdc42 Effector Activated Cdc42Hs-associated Kinase-1 via a Fyn Tyrosine Kinase Signaling Pathway. J. Biol. Chem. 276: 5622-5628 [Abstract] [Full Text]  
• Watson, J. M., Harding, T. W., Golubovskaya, V., Morris, J. S., Hunter, D., Li, X., Haskill, J. S., Earp, H. S. (2001). Inhibition of the Calcium-dependent Tyrosine Kinase (CADTK) Blocks Monocyte Spreading and Motility. J. Biol. Chem. 276: 3536-3542 [Abstract] [Full Text]  
• Anfosso, F., Bardin, N., Vivier, E., Sabatier, F., Sampol, J., Dignat-George, F. (2001). Outside-in Signaling Pathway Linked to CD146 Engagement in Human Endothelial Cells. J. Biol. Chem. 276: 1564-1569 [Abstract] [Full Text]  
• Ulivieri, C., Peter, A., Orsini, E., Palmer, E., Baldari, C. T. (2001). Defective Signaling to Fyn by a T Cell Antigen Receptor Lacking the alpha -Chain Connecting Peptide Motif. J. Biol. Chem. 276: 3574-3580 [Abstract] [Full Text]  
• Sorokin, A., Kozlowski, P., Graves, L., Philip, A. (2001). Protein-tyrosine Kinase Pyk2 Mediates Endothelin-induced p38 MAPK Activation in Glomerular Mesangial Cells. J. Biol. Chem. 276: 21521-21528 [Abstract] [Full Text]  
• Katagiri, T., Takahashi, T., Sasaki, T., Nakamura, S., Hattori, S. (2000). Protein-tyrosine Kinase Pyk2 Is Involved in Interleukin-2 Production by Jurkat T Cells via Its Tyrosine 402. J. Biol. Chem. 275: 19645-19652 [Abstract] [Full Text]  
• Gamero, A. M., Larner, A. C. (2000). Signaling via the T Cell Antigen Receptor Induces Phosphorylation of Stat1 on Serine 727. J. Biol. Chem. 275: 16574-16578 [Abstract] [Full Text]  

This Article Abstract Full Text (PDF, 261K) PPT slides of all figures Alert me when this article is cited Citation Map Services Email this article Similar articles in this journal Similar articles in PubMed Alert me to new content in the JEM Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Qian, D. Articles by Weiss, A. Search for Related Content PubMed PubMed Citation Articles by Qian, D. Articles by Weiss, A. Social Bookmarking                            What's this?