Selectivity in subunit composition of Ena/VASP tetramers
نویسندگان
چکیده
The members of the actin regulatory family of Ena/VASP proteins form stable tetramers. The vertebrate members of the Ena/VASP family, VASP, Mena and EVL, have many overlapping properties and expression patterns, but functional and regulatory differences between paralogues have been observed. The formation of mixed oligomers may serve a regulatory role to refine Ena/VASP activity. While it has been assumed that family members can form mixed oligomers, this possibility has not been investigated systematically. Using cells expressing controlled combinations of VASP, Mena and EVL, we evaluated the composition of Ena/VASP oligomers and found that VASP forms oligomers without apparent bias with itself, Mena or EVL. However, Mena and EVL showed only weak hetero-oligomerization, suggesting specificity in the association of Ena/VASP family members. Co-expression of VASP increased the ability of Mena and EVL to form mixed oligomers. Additionally, we found that the tetramerization domain (TD) at the C-termini of Ena/VASP proteins conferred the observed selectivity. Finally, we demonstrate that replacement of the TD with a synthetic tetramerizing coiled coil sequence supports homo-oligomerization and normal VASP subcellular localization.
منابع مشابه
Microsoft Word - bsr20150149
The members of the actin regulatory family of Ena/VASP proteins form stable tetramers. The vertebrate members of the Ena/VASP family, VASP, Mena, and EVL, have many overlapping properties and expression patterns, but functional and regulatory differences between paralogs have been observed. The formation of mixed oligomers may serve a regulatory role to refine Ena/VASP activity. While it has be...
متن کاملVASP is a processive actin polymerase that requires monomeric actin for barbed end association
Ena/VASP proteins regulate the actin cytoskeleton during cell migration and morphogenesis and promote assembly of both filopodial and lamellipodial actin networks. To understand the molecular mechanisms underlying their cellular functions we used total internal reflection fluorescence microscopy to visualize VASP tetramers interacting with static and growing actin filaments in vitro. We observe...
متن کاملDistinct VASP tetramers synergize in the processive elongation of individual actin filaments from clustered arrays.
Ena/VASP proteins act as actin polymerases that drive the processive elongation of filament barbed ends in membrane protrusions or at the surface of bacterial pathogens. Based on previous analyses of fast and slow elongating VASP proteins by in vitro total internal reflection fluorescence microscopy (TIRFM) and kinetic and thermodynamic measurements, we established a kinetic model of Ena/VASP-m...
متن کاملAntagonism between Ena/VASP Proteins and Actin Filament Capping Regulates Fibroblast Motility
Cell motility requires lamellipodial protrusion, a process driven by actin polymerization. Ena/VASP proteins accumulate in protruding lamellipodia and promote the rapid actin-driven motility of the pathogen Listeria. In contrast, Ena/VASP negatively regulate cell translocation. To resolve this paradox, we analyzed the function of Ena/VASP during lamellipodial protrusion. Ena/VASP-deficient lame...
متن کاملEna/VASP proteins contribute to Listeria monocytogenes pathogenesis by controlling temporal and spatial persistence of bacterial actin-based motility.
The Listeria monocytogenes surface protein ActA mediates actin-based motility by interacting with a number of host cytoskeletal components, including Ena/VASP family proteins, which in turn interact with actin and the actin-binding protein profilin. We employed a bidirectional genetic approach to study Ena/VASP's contribution to L. monocytogenes movement and pathogenesis. We generated an ActA a...
متن کامل