Vinexin alpha isoform promotes up-regulation of actin stress fiber formation. Vinexin beta isoform plays a role in cell spreading and enhances the activation of JNK/SAPK in response to EGF stimulation by using its third SH3 domain. Interacts with DLG5 through its third SH3 domain (By similarity). Interacts with vinculin by the first two SH3 domains and the proline rich region of vinculin. Binds to SOS (guanine nucleotide exchange factor of RAS and RAC), through its third SH3 domain. The formation of this complex is down-regulated by phosphorylation of SOS. Interacts with INPPL1/SHIP2, SAFB2, SOCS7 and SRCIN1. Interacts with FASLG. Interacts with MAPK1/ERK2 (By similarity). Localized at cell-extracellular matrix junctions (By similarity). Both isoforms were localized at focal adhesion and cell-cell adhesion sites. Localized at cell-extracellular matrix junctions (By similarity). Both isoforms were localized at focal adhesion and cell-cell adhesion sites, vinexin beta was also found in the nucleus. Both isoforms are expressed in different tissues like heart, placenta, brain, skeletal muscle and pancreas. Isoform beta is especially found in liver. Phosphorylated at Ser-530 by MAPK1/ERK2 during cell spreading.