Target
Human PAG1
Synonyms
PAG1 | Csk-binding protein | CBP | PAG
Reactivity
Human
(tested or 100% immunogen sequence identity)
Immunogen
Recombinant intracellular fragment (aa 97-432) of human Cbp/PAG.
Specificity
Csk binding protein, also known as PAG (phosphoprotein associated with GEMs), is a ubiquitously expressed 46 kD transmembrane adaptor protein present in membrane rafts (glycosphingolipid-enriched microdomains), which however migrates on SDS PAGE gels anomalously as an 80 kD molecule. Following tyrosine phosphorylation by Src family kinases, PAG binds and thereby activates the protein tyrosine kinase Csk, the major negative regulator of the Src family kinases. Signaling via the B-cell receptor in B cells or high affinity IgE receptor (FcepsilonRI) in mast cells leads to PAG increased tyrosine phosphorylation and Csk binding, while T cell receptor signaling causes PAG dephosphorylation, loss of Csk binding and increased activation of the protein tyrosine kinase Lck.