Phosphoprotein Associated With Glycosphingolipid Microdomains 1 (PAG1)

PAG1 is a type III transmembrane adaptor protein that binds to the tyrosine kinase csk protein. It is thought to be involved in the regulation of T cell activation.Initiation of signal transduction via immunoreceptors depends on interactions of the engaged receptor with glycosphingolipid-enriched membrane microdomains (GEMs), also known as membrane rafts. GEMs are small signaling islets that are relatively resistant to detergent solubilization except by n-alkyl glycosides. Sequence analysis predicted that the 432-amino acid type III transmembrane protein contains a 16-amino acid extracellular domain, a 20-amino acid transmembrane domain, a putative palmitoylation site, and a 397-amino acid cytoplasmic tail with 9 potential tyrosine phosphorylation sites and multiple putative casein kinase II  and protein kinase C phosphorylation sites.