Vav is a family of proteins involved in cell signalling. They act as guanine nucleotide exchange factors (GEFs) for small G protein

G protein

G proteins are a family of proteins involved in transmitting chemical signals outside the cell, and causing changes inside the cell. They communicate signals from many hormones, neurotransmitters, and other signaling factors. G protein-coupled receptors are transmembrane receptors...

s of the Rho family. GEF activity is mediated via module of tandem DH

RhoGEF domain

RhoGEF domain is a structural domain of guanine nucleotide exchange factors for Rho/Rac/Cdc42-like GTPases. It is also called "Dbl-homologous" domain.-Human proteins containing this domain :...

-PH domains. Vav proteins also appear to exhibit GEF-independent functions.

There are three members of this family:

• Vav1
  VAV1
  Proto-oncogene vav is a protein that in humans is encoded by the VAV1 gene.-Interactions:VAV1 has been shown to interact with Ku70, PLCG1, Lymphocyte cytosolic protein 2, Janus kinase 2, SIAH2, S100B, Abl gene, ARHGDIB, SHB, PIK3R1, PRKCQ, Grb2, MAPK1, Syk, Linker of activated T cells, Cbl gene and...
  
  
• Vav2
  VAV2
  Guanine nucleotide exchange factor VAV2 is a protein that in humans is encoded by the VAV2 gene.-Interactions:VAV2 has been shown to interact with CD19 and Grb2.-Further reading:...
  
  
• Vav3
  VAV3
  Guanine nucleotide exchange factor VAV3 is a protein that in humans is encoded by the VAV3 gene.-Further reading:...