Skip to main content
PMC home page
The EMBO Journal logoLink to The EMBO Journal
. 1998 May 1;17(9):2584–2595. doi: 10.1093/emboj/17.9.2584

A unique insert in the linker domain of Syk is necessary for its function in immunoreceptor signalling.

S Latour 1, J Zhang 1, R P Siraganian 1, A Veillette 1
PMCID: PMC1170600  PMID: 9564041

Abstract

Accumulating data indicate that the 'linker' region of Syk, which lies between its tandem Src homology 2 (SH2) domains and kinase region, provides a critical function for the biological activity of Syk. This importance has been ascribed to the presence of tyrosine phosphorylation sites capable of mediating the recruitment of cellular effectors. We and others previously identified an alternatively spliced variant of Syk, termed SykB, which lacks a 23 amino acid sequence in the linker domain. As this 'linker insert' is also not present in the closely related enzyme Zap-70, it seems plausible that Syk possesses this unique sequence for functional reasons. To understand its role better, we have compared the abilities of Syk and SykB to participate in immunoreceptor-triggered signal transduction. The results of our experiments revealed that, unlike Syk, SykB was inefficient at coupling stimulation of FcepsilonRI on basophils or the antigen receptor on T cells to the early and late events of cellular activation. Further studies showed that the functional defect in SykB was not caused by the absence of crucial tyrosine phosphorylation sites, or by a reduced intrinsic kinase activity. Rather, it correlated with the reduced ability of SykB to bind phosphorylated immunoreceptor tyrosine-based activation motifs (ITAMs) in vitro and in vivo. In combination, these results demonstrated that the unique insert in the linker domain of Syk is crucial for its capacity to participate in immunoreceptor signalling. Furthermore, they provided evidence that the linker region can regulate the ability of Syk to bind ITAMs, thus identifying a novel function for this domain.

Full Text

The Full Text of this article is available as a PDF (675.5 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Chan A. C., Iwashima M., Turck C. W., Weiss A. ZAP-70: a 70 kd protein-tyrosine kinase that associates with the TCR zeta chain. Cell. 1992 Nov 13;71(4):649–662. doi: 10.1016/0092-8674(92)90598-7. [DOI] [PubMed] [Google Scholar]
  2. Chan A. C., van Oers N. S., Tran A., Turka L., Law C. L., Ryan J. C., Clark E. A., Weiss A. Differential expression of ZAP-70 and Syk protein tyrosine kinases, and the role of this family of protein tyrosine kinases in TCR signaling. J Immunol. 1994 May 15;152(10):4758–4766. [PubMed] [Google Scholar]
  3. Cheng A. M., Rowley B., Pao W., Hayday A., Bolen J. B., Pawson T. Syk tyrosine kinase required for mouse viability and B-cell development. Nature. 1995 Nov 16;378(6554):303–306. doi: 10.1038/378303a0. [DOI] [PubMed] [Google Scholar]
  4. Chow L. M., Veillette A. The Src and Csk families of tyrosine protein kinases in hemopoietic cells. Semin Immunol. 1995 Aug;7(4):207–226. doi: 10.1006/smim.1995.0026. [DOI] [PubMed] [Google Scholar]
  5. Chu D. H., Spits H., Peyron J. F., Rowley R. B., Bolen J. B., Weiss A. The Syk protein tyrosine kinase can function independently of CD45 or Lck in T cell antigen receptor signaling. EMBO J. 1996 Nov 15;15(22):6251–6261. [PMC free article] [PubMed] [Google Scholar]
  6. Clark E. A., Shattil S. J., Ginsberg M. H., Bolen J., Brugge J. S. Regulation of the protein tyrosine kinase pp72syk by platelet agonists and the integrin alpha IIb beta 3. J Biol Chem. 1994 Nov 18;269(46):28859–28864. [PubMed] [Google Scholar]
  7. Costello P. S., Turner M., Walters A. E., Cunningham C. N., Bauer P. H., Downward J., Tybulewicz V. L. Critical role for the tyrosine kinase Syk in signalling through the high affinity IgE receptor of mast cells. Oncogene. 1996 Dec 19;13(12):2595–2605. [PubMed] [Google Scholar]
  8. Crowley M. T., Costello P. S., Fitzer-Attas C. J., Turner M., Meng F., Lowell C., Tybulewicz V. L., DeFranco A. L. A critical role for Syk in signal transduction and phagocytosis mediated by Fcgamma receptors on macrophages. J Exp Med. 1997 Oct 6;186(7):1027–1039. doi: 10.1084/jem.186.7.1027. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Daëron M. Fc receptor biology. Annu Rev Immunol. 1997;15:203–234. doi: 10.1146/annurev.immunol.15.1.203. [DOI] [PubMed] [Google Scholar]
  10. Deckert M., Tartare-Deckert S., Couture C., Mustelin T., Altman A. Functional and physical interactions of Syk family kinases with the Vav proto-oncogene product. Immunity. 1996 Dec;5(6):591–604. doi: 10.1016/s1074-7613(00)80273-3. [DOI] [PubMed] [Google Scholar]
  11. Evan G. I., Lewis G. K., Ramsay G., Bishop J. M. Isolation of monoclonal antibodies specific for human c-myc proto-oncogene product. Mol Cell Biol. 1985 Dec;5(12):3610–3616. doi: 10.1128/mcb.5.12.3610. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Furlong M. T., Mahrenholz A. M., Kim K. H., Ashendel C. L., Harrison M. L., Geahlen R. L. Identification of the major sites of autophosphorylation of the murine protein-tyrosine kinase Syk. Biochim Biophys Acta. 1997 Feb 4;1355(2):177–190. doi: 10.1016/s0167-4889(96)00131-0. [DOI] [PubMed] [Google Scholar]
  13. Gao J., Zoller K. E., Ginsberg M. H., Brugge J. S., Shattil S. J. Regulation of the pp72syk protein tyrosine kinase by platelet integrin alpha IIb beta 3. EMBO J. 1997 Nov 3;16(21):6414–6425. doi: 10.1093/emboj/16.21.6414. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Kimura T., Sakamoto H., Appella E., Siraganian R. P. Conformational changes induced in the protein tyrosine kinase p72syk by tyrosine phosphorylation or by binding of phosphorylated immunoreceptor tyrosine-based activation motif peptides. Mol Cell Biol. 1996 Apr;16(4):1471–1478. doi: 10.1128/mcb.16.4.1471. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Kolanus W., Romeo C., Seed B. T cell activation by clustered tyrosine kinases. Cell. 1993 Jul 16;74(1):171–183. doi: 10.1016/0092-8674(93)90304-9. [DOI] [PubMed] [Google Scholar]
  16. Latour S., Chow L. M., Veillette A. Differential intrinsic enzymatic activity of Syk and Zap-70 protein-tyrosine kinases. J Biol Chem. 1996 Sep 13;271(37):22782–22790. doi: 10.1074/jbc.271.37.22782. [DOI] [PubMed] [Google Scholar]
  17. Latour S., Fournel M., Veillette A. Regulation of T-cell antigen receptor signalling by Syk tyrosine protein kinase. Mol Cell Biol. 1997 Aug;17(8):4434–4441. doi: 10.1128/mcb.17.8.4434. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Law C. L., Chandran K. A., Sidorenko S. P., Clark E. A. Phospholipase C-gamma1 interacts with conserved phosphotyrosyl residues in the linker region of Syk and is a substrate for Syk. Mol Cell Biol. 1996 Apr;16(4):1305–1315. doi: 10.1128/mcb.16.4.1305. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Mallick-Wood C. A., Pao W., Cheng A. M., Lewis J. M., Kulkarni S., Bolen J. B., Rowley B., Tigelaar R. E., Pawson T., Hayday A. C. Disruption of epithelial gamma delta T cell repertoires by mutation of the Syk tyrosine kinase. Proc Natl Acad Sci U S A. 1996 Sep 3;93(18):9704–9709. doi: 10.1073/pnas.93.18.9704. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Minami Y., Nakagawa Y., Kawahara A., Miyazaki T., Sada K., Yamamura H., Taniguchi T. Protein tyrosine kinase Syk is associated with and activated by the IL-2 receptor: possible link with the c-myc induction pathway. Immunity. 1995 Jan;2(1):89–100. doi: 10.1016/1074-7613(95)90081-0. [DOI] [PubMed] [Google Scholar]
  21. Neumeister E. N., Zhu Y., Richard S., Terhorst C., Chan A. C., Shaw A. S. Binding of ZAP-70 to phosphorylated T-cell receptor zeta and eta enhances its autophosphorylation and generates specific binding sites for SH2 domain-containing proteins. Mol Cell Biol. 1995 Jun;15(6):3171–3178. doi: 10.1128/mcb.15.6.3171. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Ottinger E. A., Botfield M. C., Shoelson S. E. Tandem SH2 domains confer high specificity in tyrosine kinase signaling. J Biol Chem. 1998 Jan 9;273(2):729–735. doi: 10.1074/jbc.273.2.729. [DOI] [PubMed] [Google Scholar]
  23. Perlmutter R. M., Levin S. D., Appleby M. W., Anderson S. J., Alberola-Ila J. Regulation of lymphocyte function by protein phosphorylation. Annu Rev Immunol. 1993;11:451–499. doi: 10.1146/annurev.iy.11.040193.002315. [DOI] [PubMed] [Google Scholar]
  24. Reske-Kunz A. B., Rüde E. Insulin-specific T cell hybridomas derived from (H-2b x H-2k)F1 mice preferably employ F1-unique restriction elements for antigen recognition. Eur J Immunol. 1985 Oct;15(10):1048–1054. doi: 10.1002/eji.1830151017. [DOI] [PubMed] [Google Scholar]
  25. Reth M., Wienands J. Initiation and processing of signals from the B cell antigen receptor. Annu Rev Immunol. 1997;15:453–479. doi: 10.1146/annurev.immunol.15.1.453. [DOI] [PubMed] [Google Scholar]
  26. Rowley R. B., Bolen J. B., Fargnoli J. Molecular cloning of rodent p72Syk. Evidence of alternative mRNA splicing. J Biol Chem. 1995 May 26;270(21):12659–12664. doi: 10.1074/jbc.270.21.12659. [DOI] [PubMed] [Google Scholar]
  27. Staerz U. D., Rammensee H. G., Benedetto J. D., Bevan M. J. Characterization of a murine monoclonal antibody specific for an allotypic determinant on T cell antigen receptor. J Immunol. 1985 Jun;134(6):3994–4000. [PubMed] [Google Scholar]
  28. Takata M., Sabe H., Hata A., Inazu T., Homma Y., Nukada T., Yamamura H., Kurosaki T. Tyrosine kinases Lyn and Syk regulate B cell receptor-coupled Ca2+ mobilization through distinct pathways. EMBO J. 1994 Mar 15;13(6):1341–1349. doi: 10.1002/j.1460-2075.1994.tb06387.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Taniguchi T., Kobayashi T., Kondo J., Takahashi K., Nakamura H., Suzuki J., Nagai K., Yamada T., Nakamura S., Yamamura H. Molecular cloning of a porcine gene syk that encodes a 72-kDa protein-tyrosine kinase showing high susceptibility to proteolysis. J Biol Chem. 1991 Aug 25;266(24):15790–15796. [PubMed] [Google Scholar]
  30. Taylor N., Jahn T., Smith S., Lamkin T., Uribe L., Liu Y., Durden D. L., Weinberg K. Differential activation of the tyrosine kinases ZAP-70 and Syk after Fc gamma RI stimulation. Blood. 1997 Jan 15;89(2):388–396. [PubMed] [Google Scholar]
  31. Turner M., Mee P. J., Costello P. S., Williams O., Price A. A., Duddy L. P., Furlong M. T., Geahlen R. L., Tybulewicz V. L. Perinatal lethality and blocked B-cell development in mice lacking the tyrosine kinase Syk. Nature. 1995 Nov 16;378(6554):298–302. doi: 10.1038/378298a0. [DOI] [PubMed] [Google Scholar]
  32. Veillette A., Bookman M. A., Horak E. M., Bolen J. B. The CD4 and CD8 T cell surface antigens are associated with the internal membrane tyrosine-protein kinase p56lck. Cell. 1988 Oct 21;55(2):301–308. doi: 10.1016/0092-8674(88)90053-0. [DOI] [PubMed] [Google Scholar]
  33. Wan Y., Kurosaki T., Huang X. Y. Tyrosine kinases in activation of the MAP kinase cascade by G-protein-coupled receptors. Nature. 1996 Apr 11;380(6574):541–544. doi: 10.1038/380541a0. [DOI] [PubMed] [Google Scholar]
  34. Wange R. L., Samelson L. E. Complex complexes: signaling at the TCR. Immunity. 1996 Sep;5(3):197–205. doi: 10.1016/s1074-7613(00)80315-5. [DOI] [PubMed] [Google Scholar]
  35. Weiss A., Littman D. R. Signal transduction by lymphocyte antigen receptors. Cell. 1994 Jan 28;76(2):263–274. doi: 10.1016/0092-8674(94)90334-4. [DOI] [PubMed] [Google Scholar]
  36. Williams S., Couture C., Gilman J., Jascur T., Deckert M., Altman A., Mustelin T. Reconstitution of T cell antigen receptor-induced Erk2 kinase activation in Lck-negative JCaM1 cells by Syk. Eur J Biochem. 1997 Apr 1;245(1):84–90. doi: 10.1111/j.1432-1033.1997.00084.x. [DOI] [PubMed] [Google Scholar]
  37. Wu J., Zhao Q., Kurosaki T., Weiss A. The Vav binding site (Y315) in ZAP-70 is critical for antigen receptor-mediated signal transduction. J Exp Med. 1997 May 19;185(10):1877–1882. doi: 10.1084/jem.185.10.1877. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Yagi S., Suzuki K., Hasegawa A., Okumura K., Ra C. Cloning of the cDNA for the deleted syk kinase homologous to ZAP-70 from human basophilic leukemia cell line (KU812). Biochem Biophys Res Commun. 1994 Apr 15;200(1):28–34. doi: 10.1006/bbrc.1994.1409. [DOI] [PubMed] [Google Scholar]
  39. Zhang J., Berenstein E. H., Evans R. L., Siraganian R. P. Transfection of Syk protein tyrosine kinase reconstitutes high affinity IgE receptor-mediated degranulation in a Syk-negative variant of rat basophilic leukemia RBL-2H3 cells. J Exp Med. 1996 Jul 1;184(1):71–79. doi: 10.1084/jem.184.1.71. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Zioncheck T. F., Harrison M. L., Isaacson C. C., Geahlen R. L. Generation of an active protein-tyrosine kinase from lymphocytes by proteolysis. J Biol Chem. 1988 Dec 15;263(35):19195–19202. [PubMed] [Google Scholar]
  41. Zoller K. E., MacNeil I. A., Brugge J. S. Protein tyrosine kinases Syk and ZAP-70 display distinct requirements for Src family kinases in immune response receptor signal transduction. J Immunol. 1997 Feb 15;158(4):1650–1659. [PubMed] [Google Scholar]
  42. van Oers N. S., Weiss A. The Syk/ZAP-70 protein tyrosine kinase connection to antigen receptor signalling processes. Semin Immunol. 1995 Aug;7(4):227–236. doi: 10.1006/smim.1995.0027. [DOI] [PubMed] [Google Scholar]

Articles from The EMBO Journal are provided here courtesy of Nature Publishing Group

RESOURCES