Yes / The Cdc42- and Rac-interactive binding motif (CRIB) of coronin binds to Rho GTPases with a preference for GDP-loaded Rac. Mutation of the Cdc42- and Rac-interactive binding motif abrogates Rac binding. This results in increased 1evels of activated Rac in coronin-deficient Dictyostelium cells (corA−), which impacts myosin II assembly. corA− cells show increased accumulation of myosin II in the cortex of growth-phase cells. Myosin II assembly is regulated by myosin heavy chain kinase–mediated phosphorylation of its tail. Kinase activity depends on the activation state of the p21-activated kinase a. The myosin II defect of corA− mutant is alleviated by dominant-negative p21-activated kinase a. It is rescued by wild-type coronin, whereas coronin carrying a mutated Cdc42- and Rac-interactive binding motif failed to rescue the myosin defect in corA− mutant cells. Ectopically expressed myosin heavy chain kinases affinity purified from corA− cells show reduced kinase activity. We propose that coronin through its affinity for GDP–Rac regulates the availability of GTP–Rac for activation of downstream effectors. / This work was supported by Deutsche Forschungsgemeinschaft (DFG), Sonderforschungsbereich 670 (SFB 670) and Köln Fortune (to A.A.N.). A.M.-T. acknowledges support by the SFB 914, and J.F. acknowledges support by Grant FA330/6-1 within the framework of the DFG priority programme “Principles and Evolution of Actin Nucleator Complexes” (SPP1464). Work in F.R. lab is supported by grants from the Hull York Medical School.
Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/17710 |
Date | 28 February 2020 |
Creators | Swaminathan, Karthic, Müller-Taubenberger, A., Faix, J., Rivero, F., Noegel, A.A. |
Source Sets | Bradford Scholars |
Language | English |
Detected Language | English |
Type | Article, Accepted manuscript |
Rights | © 2013 The Authors. Reproduced in accordance with the publisher's self-archiving policy., Unspecified |
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