» Articles » PMID: 10856225

Phosphatidylinositol 3,4,5-trisphosphate Regulates Ca(2+) Entry Via Btk in Platelets and Megakaryocytes Without Increasing Phospholipase C Activity

Overview
Journal EMBO J
Date 2000 Jun 17
PMID 10856225
Citations 24
Authors
Affiliations
Soon will be listed here.
Abstract

The role of phosphatidylinositol 3,4,5-trisphosphate (PI3,4,5P(3)) and Btk in signalling by the collagen receptor glycoprotein VI was investigated. PI3,4,5P(3) was increased in platelets from mice deficient in the SH2 domain-containing inositol 5-phosphatase (SHIP), in response to collagen related peptide (CRP). Tyrosine phosphorylation and activation of phospholipase Cgamma2 (PLCgamma2) were unaltered in SHIP(-/-) platelets, whereas Btk was heavily tyrosine phosphorylated under basal conditions and maximally phosphorylated by low concentrations of CRP. There was an increase in basal Ca(2+), maximal expression of P-selectin, and potentiation of Ca(2+) and aminophospholipid exposure to CRP in SHIP(-/-) platelets in the presence of Ca(2+) (1 mM). Microinjection of PI3,4, 5P(3) into megakaryocytes caused a 3-fold increase in Ca(2+) in response to CRP, which was absent in X-linked immunodeficiency (Xid) mice, which have a mutation in the PH domain of Btk. There was a corresponding partial reduction in the sustained level of intracellular Ca(2+) in response to CRP in Xid mice but no change in PLC activity. These results demonstrate a novel pathway of Ca(2+) entry that involves PI3,4,5P(3) and Btk, and which is independent of increased PLC activity.

Citing Articles

Vav family exchange factors: Potential regulator in atherosclerosis.

Zhang Y, Ren Y, Zhou T, Qian Z, Bao Z Biochem Biophys Rep. 2024; 40:101878.

PMID: 39649800 PMC: 11625217. DOI: 10.1016/j.bbrep.2024.101878.


Biochemical Pathways Delivering Distinct Glycosphingolipid Patterns in MDA-MB-231 and MCF-7 Breast Cancer Cells.

Markotic A, Omerovic J, Marijan S, Rezic-Muzinic N, culic V Curr Issues Mol Biol. 2024; 46(9):10200-10217.

PMID: 39329960 PMC: 11430773. DOI: 10.3390/cimb46090608.


PI3K Isoform Signalling in Platelets.

Schrottmaier W, Mussbacher M, Salzmann M, Kral-Pointner J, Assinger A Curr Top Microbiol Immunol. 2022; 436:255-285.

PMID: 36243848 DOI: 10.1007/978-3-031-06566-8_11.


Comparison of inhibitory effects of irreversible and reversible Btk inhibitors on platelet function.

Tullemans B, Karel M, Leopold V, Ten Brink M, Baaten C, Maas S EJHaem. 2022; 2(4):685-699.

PMID: 35845214 PMC: 9175945. DOI: 10.1002/jha2.269.


Abivertinib inhibits megakaryocyte differentiation and platelet biogenesis.

Huang J, Huang X, Li Y, Li X, Wang J, Li F Front Med. 2021; 16(3):416-428.

PMID: 34792736 DOI: 10.1007/s11684-021-0838-5.


References
1.
Giuriato S, Payrastre B, Drayer A, Plantavid M, Woscholski R, Parker P . Tyrosine phosphorylation and relocation of SHIP are integrin-mediated in thrombin-stimulated human blood platelets. J Biol Chem. 1997; 272(43):26857-63. DOI: 10.1074/jbc.272.43.26857. View

2.
Gibbins J, Okuma M, Farndale R, Barnes M, Watson S . Glycoprotein VI is the collagen receptor in platelets which underlies tyrosine phosphorylation of the Fc receptor gamma-chain. FEBS Lett. 1997; 413(2):255-9. DOI: 10.1016/s0014-5793(97)00926-5. View

3.
Li Z, Wahl M, Eguinoa A, Stephens L, Hawkins P, Witte O . Phosphatidylinositol 3-kinase-gamma activates Bruton's tyrosine kinase in concert with Src family kinases. Proc Natl Acad Sci U S A. 1998; 94(25):13820-5. PMC: 28391. DOI: 10.1073/pnas.94.25.13820. View

4.
Falasca M, Logan S, Lehto V, Baccante G, Lemmon M, Schlessinger J . Activation of phospholipase C gamma by PI 3-kinase-induced PH domain-mediated membrane targeting. EMBO J. 1998; 17(2):414-22. PMC: 1170392. DOI: 10.1093/emboj/17.2.414. View

5.
Kehrel B, Wierwille S, Clemetson K, Anders O, Steiner M, Knight C . Glycoprotein VI is a major collagen receptor for platelet activation: it recognizes the platelet-activating quaternary structure of collagen, whereas CD36, glycoprotein IIb/IIIa, and von Willebrand factor do not. Blood. 1998; 91(2):491-9. View