CD45 Mouse, Unlabeled, Clone: 69, BD

Description

• CD45 (also known as leukocyte common antigen, GP180, or T200) is found on all hematopoietic cells except those of red cell origin
• The N-terminal domain is a large glycosylated extracellular region of variable length (390-542 amino acids) derived by the alternative splicing of at least three exons (4, 5, or 6)
• This variation accounts for the different isoforms of CD45 (180-220 kDa)
• The remainder of the molecule includes a short transmembrane region followed by a large highly conserved cytoplasmic domain of 702 residues
• The CD45 cytoplasmic domain possesses an intrinsic protein tyrosine phosphatase (PTPase) activity
• This region contains two PTPase domains (domains I and II) which share 40% homology
• Both domains are required for optimal PTPase activity and show significant homology with other receptor-like and cytoplasmic PTPases
• CD45 plays a critical role in antigen receptor-induced responses of T and B cells
• In B cells, CD45 can exist as part of a larger multisubunit complex composed of several tyrosine phosphorylated proteins, including the Src-family PTK, Lyn, or it can exist as the membrane immunoglobulin-associated MB-1/B29 heterodimer
• In T cells, CD45 associates with and dephosphorylates both lck and fyn
• In addition, CD45 can associate with membrane proteins involved in T cell activation, such as CD2, Thy-1, TCR, and CD26.