Vav
proteins are evolutionarily conserved from nematodes to mammals and play a
pivotal role in many aspects of cellular signaling, coupling cell surface
receptors to various effectors functions. In mammals, there are three family
members; Vav1 is specifically expressed in the hematopoietic
system, whereas Vav2 and Vav3 are more ubiquitously expressed. Vav proteins contain multiple domains that enable their
function in various fashions. The participation of the Vav
proteins in several processes that require cytoskeletal
reorganization, such as the formation of the immunological synapse (IS), phagocytosis, platelet aggregation, spreading, and
transformation will be discussed in this review. We will also cover how the Vav proteins succeed in controlling these processes by
their function as guanine nucleotide exchange factors (GEFs)
for the Rho/Rac family of GTPases.
The contribution of the Vav proteins in a
GEF-independent manner to the organization of the cytoskeleton will also be
deliberated. The scope of this review is to highlight the numerous roles of the
Vav signal transducer proteins in actin
organization.