Display options
Share it on

J Thromb Thrombolysis. 1998 Sep;6(2):117-124. doi: 10.1023/A:1008845421381.

Tyrosine Phosphorylation of Moesin in Arachidonic Acid-Stimulated Human Platelets.

Journal of thrombosis and thrombolysis

Meyer, Uher, Schwartz, Buchwald

Affiliations

  1. Department of Cardiology, University of Göttingen, Göttingen, Germany.

PMID: 10751793 DOI: 10.1023/A:1008845421381

Abstract

Moesin, a member of the ezrin/radixin/moesin (ERM) family of cytoskeletal proteins, has been implicated in dynamic membrane-based processes such as the formation and stabilization of filopodia. Ezrin is known to be a substrate of tyrosine kinases in activated T cells and epithelial growth factor-stimulated A431 cells. For the closely related 77-kD protein moesin, which shares 72% identity with ezrin on the basis of their amino acid sequences, a reversible phosphorylation on tyrosine residues has not yet been described. Because our scanning electron microscopy studies revealed the appearance of multiple, up to 3 µm long filopodia on the surface of activated human platelets, we investigated the participation of moesin in dynamic shape changes on platelet stimulation with arachidonic acid. Antimoesin immunoprecipitates obtained under denaturing conditions from lysates of resting platelets contained only low amounts of tyrosine-phosphorylated moesin. In lysates of arachidonic acid-stimulated platelets, the level of tyrosine phosphorylation was significantly increased. This activation-dependent phosphorylation of moesin was verified by probing antiphosphotyrosine immunoprecipitates from unstimulated and stimulated platelets with antimoesin antibodies. Tyrosine-phosphorylated moesin was detectable only in the presence of the tyrosine phosphatase inhibitor vanadate, suggesting that a coordinated balance between kinase and phosphatase activities controls the steady-state level of moesin phosphorylation.

References

  1. J Cell Biol. 1986 Feb;102(2):660-9 - PubMed
  2. J Biol Chem. 1994 Oct 28;269(43):27093-9 - PubMed
  3. J Cell Biol. 1994 Jul;126(2):391-401 - PubMed
  4. Proc Natl Acad Sci U S A. 1995 Aug 1;92 (16):7495-9 - PubMed
  5. Blood. 1982 Mar;59(3):466-71 - PubMed
  6. J Cell Biochem. 1992 Nov;50(3):237-44 - PubMed
  7. Exp Cell Res. 1995 Jul;219(1):180-96 - PubMed
  8. Exp Cell Res. 1995 Nov;221(1):197-204 - PubMed
  9. Proc Natl Acad Sci U S A. 1991 Oct 1;88(19):8297-301 - PubMed
  10. Proc Natl Acad Sci U S A. 1989 Feb;86(3):901-5 - PubMed
  11. J Cell Sci. 1992 Sep;103 ( Pt 1):131-43 - PubMed
  12. J Cell Sci. 1993 Dec;106 ( Pt 4):1189-99 - PubMed
  13. J Biol Chem. 1993 Jul 25;268(21):15868-77 - PubMed
  14. J Biol Chem. 1992 Sep 25;267(27):19258-65 - PubMed
  15. J Cell Biol. 1989 Mar;108(3):921-30 - PubMed
  16. J Cell Biol. 1994 Jun;125(6):1371-84 - PubMed
  17. J Biol Chem. 1983 Sep 25;258(18):11236-42 - PubMed
  18. J Biol Chem. 1995 Jul 14;270(28):16781-7 - PubMed
  19. J Cell Sci. 1994 Sep;107 ( Pt 9):2509-21 - PubMed
  20. Oncogene. 1993 May;8(5):1335-45 - PubMed
  21. J Cell Sci. 1993 May;105 ( Pt 1):219-31 - PubMed
  22. J Cell Biol. 1994 Sep;126(6):1445-53 - PubMed
  23. Am J Pathol. 1986 Apr;123(1):86-94 - PubMed
  24. Blood. 1994 Dec 1;84(11):3715-23 - PubMed
  25. J Cell Biol. 1995 Mar;128(6):1081-93 - PubMed
  26. J Cell Sci. 1994 Jul;107 ( Pt 7):1921-8 - PubMed
  27. J Immunol. 1992 Sep 15;149(6):1847-52 - PubMed
  28. J Biol Chem. 1989 May 5;264(13):7089-91 - PubMed
  29. J Cell Biol. 1992 Nov;119(4):905-12 - PubMed
  30. J Biol Chem. 1995 Dec 29;270(52):31377-85 - PubMed
  31. Nature. 1996 Jul 18;382(6588):265-8 - PubMed
  32. Mol Biol Cell. 1995 Aug;6(8):1061-75 - PubMed
  33. Proc Natl Acad Sci U S A. 1993 Nov 15;90(22):10846-50 - PubMed
  34. Am J Pathol. 1984 Nov;117(2):207-17 - PubMed

Publication Types