CD19 is a type I transmembrane protein and member of the immunoglobulin superfamily that functions as a B cell receptor (BCR) co-receptor.1,2 It is composed of an extracellular N-terminal domain containing two C2-type immunoglobulin-like (Ig-like) domains and several glycosylation sites, a transmembrane domain, and a C-terminal cytoplasmic domain containing nine tyrosine residues, which are subject to phosphorylation and mediate intracellular signaling. It is expressed on the surface of, and used as a marker for, B cells, and its expression increases during B cell maturation but decreases upon plasma cell differentiation.1,2,3 CD19 has important roles in B cell proliferation, differentiation, and survival.1 It associates with CD21, also known as complement receptor 2 (CR2), as well as CD82 and Leu-13, forming a multimeric complex that enhances BCR signaling.1,2 CD19 functions as an adaptor protein, recruiting various cytoplasmic signaling proteins to the cell membrane that activate numerous intracellular signaling pathways, including PI3K, MAPK, and NF-κB.1,2,4 CD19 protein levels are increased in tumor cells isolated from patients with a variety of cancers of B cell origin, including chronic myelocytic leukemia and B cell lymphomas, and decreased in B cells isolated from patients with systemic lupus erythematosus (SLE).5,6,3,2,1 Cayman’s CD19 (C-Term) Rabbit Monoclonal Antibody (Clone RM332) can be used for immunohistochemistry (IHC) and Western blot (WB) applications.WARNING This product is not for human or veterinary use.
