Overview:

B-lymphocyte antigen CD19 is a type I transmembrane protein present on all B cells and is a dominant signaling component of mature B cells (1). CD19 acts as a critical coreceptor for B cell receptor (BCR) signal transduction by recruiting and amplifying the activation of Src-family protein tyrosine kinases such as Lyn and Fyn (1). CD19 also enhances BCR-induced signaling crucial for B cell expansion through recruitment and activation of PI3K and downstream AKT kinases (1,2). CD19-deficient humans and mice exhibit hypo-responsiveness to transmembrane signals, and weak T cell-dependent humoral responses, leading to an overall impaired immune response (1).

Genbank Number:

P15391

References:

1. Wang, K., Wei, G. & Liu, D. CD19: a biomarker for B cell development, lymphoma diagnosis and therapy. Exp Hematol Oncol. 2012, 31:1.
2. Del Nagro, C.J. et al. CD19 function in central and peripheral B-cell development. Immunol Res. 2005, 31(2):119-31.