CD19

This gene encodes a member of the immunoglobulin gene superfamily. Expression of this cell surface protein is restricted to B cell lymphocytes. This protein is a reliable marker for pre-B cells but its expression diminishes during terminal B cell differentiation in antibody secreting plasma cells. The protein has two N-terminal extracellular Ig-like domains separated by a non-Ig-like domain, a hydrophobic transmembrane domain, and a large C-terminal cytoplasmic domain. This protein forms a complex with several membrane proteins including complement receptor type 2 (CD21) and tetraspanin (CD81) and this complex reduces the threshold for antigen-initiated B cell activation. Activation of this B-cell antigen receptor complex activates the phosphatidylinositol 3-kinase signalling pathway and the subsequent release of intracellular stores of calcium ions. This protein is a target of chimeric antigen receptor (CAR) T-cells used in the treatment of lymphoblastic leukemia. Mutations in this gene are associated with the disease common variable immunodeficiency 3 (CVID3) which results in a failure of B-cell differentiation and impaired secretion of immunoglobulins. CVID3 is characterized by hypogammaglobulinemia, an inability to mount an antibody response to antigen, and recurrent bacterial infections. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Jul 2020]

A protein domain is a distinct structural or functional region within a protein that can evolve, function, and exist independently of the rest of the protein chain. These domains in human CD19 often fold into stable, three-dimensional structures and are associated with specific biological functions, such as binding to DNA, other proteins, or small molecules.

Biological processes and signaling networks where the CD19 gene in human plays a role, providing insight into its function and relevance in health or disease.

The most significant associations for this gene, including commonly observed domains, pathway involvement, and functional highlights based on current data.

Locations within the cell where the protein is known or predicted to be active, providing insight into its function and cellular context.

Describes the biological processes, cellular components, and molecular functions associated with the human CD19 gene, providing context for its role in the cell.