HGNC Approved Gene Symbol: CD37
Cytogenetic location: 19q13.33 Genomic coordinates (GRCh38): 19:49,335,406-49,340,606 (from NCBI)
CD37 is a membrane protein of the tetraspanin superfamily, which includes CD9 (143030), CD53 (151525), CD81 (186845), and the R2 antigen (KAI1; 600623) among others. Many of these molecules are expressed on leukocytes and have been implicated in signal transduction, cell-cell interactions, and cellular activation and development (summary by Knobeloch et al., 2000).
Virtaneva et al. (1993) found that the CD37, CD53, and KAI1 proteins have 4 hydrophobic membrane-spanning regions and a single major extracellular loop. Both N- and C-termini of the polypeptides are probably located in the cytoplasm. The 3 antigens appear to have a higher sequence similarity (33%) to each other than to other members of the family. The CD37 antigen is strongly expressed on the surface of B cells and only weakly on a subpopulation of T cells. The CD53 glycoprotein is a pan-leukocyte marker widely expressed on hemopoietic cells. The R2 antigen appears to be upregulated in activated T cells.
By study of human/rodent somatic cell hybrids, Virtaneva et al. (1993) demonstrated that these 3 similar antigens are encoded by genes on distinct chromosomes; CD37 mapped to 19p13-q13.4, CD53 to 1p31-p12, and R2 to 11p12.
Knobeloch et al. (2000) generated and analyzed mice deficient for CD37. Despite the high expression of CD37 on cells of the immune system, no changes in development and cellular composition of lymphoid organs were observed in mice lacking CD37. A reduced level of immunoglobulin G1 (IgG1) was found in the sera of nonimmunized mice and an alteration of responses to T cell-dependent antigens. Antibody responses were observed that could be overcome by the immunization of antigen together with adjuvant. These results suggested a role for CD37 in T-cell/B-cell interactions, which is manifested under suboptimal costimulatory conditions.
Knobeloch, K.-P., Wright, M. D., Ochsenbein, A. F., Liesenfeld, O., Lohler, J., Zinkernagel, R. M., Horak, I., Orinska, Z. Targeted inactivation of the tetraspanin CD37 impairs T-cell-dependent B-cell response under suboptimal costimulatory conditions. Molec. Cell. Biol. 20: 5363-5369, 2000. [PubMed: 10891477] [Full Text: https://doi.org/10.1128/MCB.20.15.5363-5369.2000]
Virtaneva, K. I., Angelisova, P., Baumruker, T., Horejsi, V., Nevanlinna, H., Schroder, J. The genes for CD37, CD53, and R2, all members of a novel gene family, are located on different chromosomes. Immunogenetics 37: 461-465, 1993. [PubMed: 8436422] [Full Text: https://doi.org/10.1007/BF00222471]