CD19 Antibody – Rat Monoclonal

Lymphocytes proliferate and differentiate in response to various concentrations of different antigens. The ability of the B cell to respond in a specific, yet sensitive manner to the various antigens is achieved with the use of low-affinity antigen receptors. This gene encodes a cell surface molecule which assembles with the antigen receptor of B lymphocytes in order to decrease the threshold for antigen receptor-dependent stimulation. [provided by RefSeq, Jul 2008]

Function: Assembles with the antigen receptor of B-lymphocytes in order to decrease the threshold for antigen receptor-dependent stimulation.

Subunit structure: Forms a complex with CD21, CD81 and CD225 in the membrane of mature B-cells. Interacts with VAV. Interacts with GRB2 and SOS when phosphorylated on Tyr-348 and/or Tyr-378. Interacts with PLCG2 when phosphorylated on Tyr-409. Interacts with LYN. Ref.11 Ref.13

Subcellular location: Membrane; Single-pass type I membrane protein.

Post-translational modification: Phosphorylated on serine and threonine upon DNA damage, probably by ATM or ATR. Phosphorylated on tyrosine following B-cell activation. Phosphorylated on tyrosine residues by LYN. Ref.11 Ref.12 Ref.13

Involvement in disease: Immunodeficiency, common variable, 3 (CVID3) [MIM:613493]: A primary immunodeficiency characterized by antibody deficiency, hypogammaglobulinemia, recurrent bacterial infections and an inability to mount an antibody response to antigen. The defect results from a failure of B-cell differentiation and impaired secretion of immunoglobulins; the numbers of circulating B cells is usually in the normal range, but can be low.Note: The disease is caused by mutations affecting the gene represented in this entry. Ref.14

Sequence similarities: Contains 2 Ig-like C2-type (immunoglobulin-like) domains.

Sequence caution: The sequence AAA35533.1 differs from that shown. Reason: Frameshift at position 396.