anti-PAG [Cbp], pAb (IG-452)

PAG [Cbp] is a ubiquitously expressed transmembrane adapter protein. Depending on its phosphorylation status, it appears as diffuse band(s) of 80-90kDa by SDS-PAGE, with phosphorylation leading to a shift towards a higher apparent molecular mass. Tyrosine phosphorylated PAG recruits Csk to the membrane and negatively regulates Src family kinases via Csk-mediated phosphorylation. Upon T cell receptor engagement, PAG becomes dephosphorylated, thereby displacing Csk from the membrane and enabling the activation of the Src kinases Fyn and Lck. PAG negatively regulates TCR (T cell antigen receptor)-mediated signaling in T cells and FCER1 (high affinity immunoglobulin epsilon receptor)-mediated signaling in mast cells. It promotes CSK activation and recruitment to lipid rafts, which results in LCK inhibition. It inhibits immunological synapse formation by preventing dynamic arrangement of lipid raft proteins and may be involved in cell adhesion signaling.