CD19 Functions as coreceptor for the B-cell antigen receptor complex (BCR) on B-lymphocytes. Decreases the threshold for activation of downstream signaling pathways and for triggering B-cell responses to antigens. Activates signaling pathways that lead to the activation of phosphatidylinositol 3-kinase and the mobilization of intracellular Ca(2+) stores. Is not required for early steps during B cell differentiation in the blood marrow. Required for normal differentiation of B-1 cells. Required for normal B cell differentiation and proliferation in response to antigen challenges. Required for normal levels of serum immunoglobulins, and for production of high-affinity antibodies in response to antigen challenge. Detected on marginal zone and germinal center B cells in lymph nodes (PubMed:2463100). Detected on blood B cells (at protein level) (PubMed:2463100, PubMed:16672701). 2 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
Protein type: Cell surface; Membrane protein, integral
Chromosomal Location of human Ortholog: 16p11.2
Cellular Component:  external side of plasma membrane; membrane raft; plasma membrane; protein-containing complex
Biological Process:  antigen receptor-mediated signaling pathway; B cell proliferation involved in immune response; B cell receptor signaling pathway; B-1 B cell differentiation; immunoglobulin mediated immune response; positive regulation of phosphatidylinositol 3-kinase activity; positive regulation of release of sequestered calcium ion into cytosol; regulation of B cell activation; regulation of B cell receptor signaling pathway
Disease: Immunodeficiency, Common Variable, 2; Immunodeficiency, Common Variable, 3
Reference #:  P15391 (UniProtKB)
Alt. Names/Synonyms: B-lymphocyte antigen CD19; B-lymphocyte surface antigen B4; B4; CD19; CD19 antigen; CD19 molecule; CVID3; Differentiation antigen CD19; MGC12802; T-cell surface antigen Leu-12
Gene Symbols: CD19
Molecular weight: 61,128 Da
Basal Isoelectric point: 4.87  Predict pI for various phosphorylation states
CST Pathways:  B Cell Receptor Signaling  |  PI3K/Akt Signaling
Protein-Specific Antibodies, siRNAs or Recombinant Proteins from Cell Signaling Technology® Total Proteins
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CD19

Protein Structure Not Found.


Cross-references to other databases:  AlphaFold  |  STRING  |  cBioPortal  |  Wikipedia  |  Reactome  |  neXtProt  |  Protein Atlas  |  BioGPS  |  Pfam  |  RCSB PDB  |  Phospho.ELM  |  NetworKIN  |  GeneCards  |  UniProtKB  |  Entrez-Gene  |  GenPept  |  Ensembl Gene  |  Ensembl Protein