Overview:

VAV is a proto-oncogene that is a member of the Dbl family of guanine nucleotide exchange factors (GEF) for the Rho family of GTP binding proteins. VAV plays a vital role in hematopoiesis and in T-cell and B-cell development as well as in their activation. VAV is the specific binding partner of Nef proteins from HIV-1 (1). Co-expression and binding of these VAV partners initiates profound morphological changes, cytoskeletal rearrangements and JNK/SAPK pathway activation leading to increased levels of viral transcription and replication. VAV is also the guanine nucleotide dissociation inhibitor for Ras.

References:

1. Fackler, O T. et al: Activation of Vav by Nef induces cytoskeletal rearrangements and downstream effector functions. Molec. Cell 3729-739, 1999.