Calcium-dependent interaction of GIT and PIX with gamma-tubulin regulates microtubule nucleation from centrosomes in bone-marrow derived mast cells

0431741 - ÚMG 2015 CZ eng A - Abstract
Sulimenko, Vadym - Hájková, Zuzana - Sulimenko, Tetyana - Černohorská, Markéta - Sládková, Vladimíra - Dráberová, Eduarda - Dráber, Pavel
Calcium-dependent interaction of GIT and PIX with gamma-tubulin regulates microtubule nucleation from centrosomes in bone-marrow derived mast cells.
Cytoskeletal club 2014. Vranovská Ves, 2014.
[Cytoskeletal club 2014. 21.05.2014-23.5.2014, Vranovská Ves]
R&D Projects: GA ČR GAP302/12/1673
Institutional support: RVO:68378050
Subject RIV: EB - Genetics ; Molecular Biology

Activation of mast cells leads to substantial changes of cell morphology, translocation of granules to plasma membrane and exocytosis of inflammatory mediators. Reorganization of highly dynamic microtubules (MTs) and microfilaments is pivotal in these processes. Formation of MTs in the course of mast cell activation depends on protein phosphorylation and Ca2+ concentration.Gama-Tubulin ring complexes are key regulators of MT nucleation and organization. We have found, that except of known Gama-tubulin-complex proteins (GCPs), -tubulin interacts with GIT1 and betaPIX signaling proteins in bone-marrow mast cells (BMMCs). Moreover, GIT1 and betaPIX associate with centrosomes in BMMCs. Here we show, that changes in Ca2+ levels in BMMCs lysates affect gama-tubulin properties and its interactions with GCPs, GIT and PIX proteins. Pull-down experiments with truncated forms of gama-tubulin revealed that Ca2+-dependent factor from BMMCs modified the C-terminal gama-tubulin region. Depletion of GIT1 and betaPIX in BMMCs led to significant changes in MT nucleation from centrosomes in nocodazole washout experiments. Combined data indicate that GIT1 and betaPIX interact with gama-tubulin in Ca2+-dependent manner and might play important role in the regulation of MT organization in mast cells.
Permanent Link: http://hdl.handle.net/11104/0236323