Walders-Harbeck Birgit, Khaitlina Sofia Y, Hinssen Horst, Jockusch Brigitte M, Illenberger Susanne
Cell Biology, Zoological Institute, Technical University of Braunschweig, Biocenter, Spielmannstrasse 7, D-38092 Braunschweig, Germany.
FEBS Lett. 2002 Oct 9;529(2-3):275-80. doi: 10.1016/s0014-5793(02)03356-2.
The vasodilator-stimulated phosphoprotein (VASP) functions as a cellular regulator of actin dynamics. VASP may initialise actin polymerisation, suggesting a direct interaction with monomeric actin. The present study demonstrates that VASP directly binds to actin monomers and that complex formation depends on a conserved four amino acid motif in the EVH2 domain. Point mutations within this motif drastically weaken VASP/G-actin interactions, thereby abolishing any actin-nucleating activity of VASP. Additionally, actin nucleation was found to depend on VASP oligomerisation since VASP monomers fail to induce the formation of actin filaments. Phosphorylation negatively affects VASP/G-actin interactions preventing VASP-induced actin filament formation.
血管舒张刺激磷蛋白（VASP）作为肌动蛋白动力学的细胞调节剂发挥作用。VASP可能启动肌动蛋白聚合，这表明它与单体肌动蛋白存在直接相互作用。本研究表明，VASP直接与肌动蛋白单体结合，且复合物的形成取决于EVH2结构域中一个保守的四氨基酸基序。该基序内的点突变会大幅削弱VASP与肌动蛋白单体的相互作用，从而消除VASP的任何肌动蛋白成核活性。此外，发现肌动蛋白成核依赖于VASP的寡聚化，因为VASP单体无法诱导肌动蛋白丝的形成。磷酸化会对VASP与肌动蛋白单体的相互作用产生负面影响，从而阻止VASP诱导的肌动蛋白丝形成。
