First Author | Torres RM | Year | 1992 |
Journal | J Immunol | Volume | 148 |
Issue | 2 | Pages | 620-6 |
PubMed ID | 1370315 | Mgi Jnum | J:11564 |
Mgi Id | MGI:59978 | Doi | 10.4049/jimmunol.148.2.620 |
Citation | Torres RM, et al. (1992) Differential increase of an alternatively polyadenylated mRNA species of murine CD40 upon B lymphocyte activation. J Immunol 148(2):620-6 |
abstractText | CD40 is an integral membrane glycoprotein found on the surface of human B lymphocytes. Antibodies specific for CD40 have been shown to augment proliferation of activated B lymphocytes, prevent B lymphocyte apoptosis, and prolong the maintenance of normal B lymphocytes in culture. As a step toward developing an in vivo system to examine CD40 function, a molecular clone encoding the murine homologue of the human CD40 B lymphocyte surface Ag was isolated and characterized. Throughout their open reading frames, the murine and human proteins shared 62% predicted amino acid identity. Within the cytoplasmic domain, which includes a completely conserved region known to be important for signaling by human CD40, the CD40 homologues are 78% identical. The human and murine proteins are members of a new cytokine receptor family, which includes the receptors for nerve growth factor and TNF-alpha, that are homologous in their cysteine-rich extracellular domains. The murine CD40 gene is expressed in B lymphocytes as two mRNA species generated by alternative usage of polyadenylation signals in the 3' untranslated region. The activation of B lymphocytes differentially increases the relative levels of these two mRNA transcripts suggesting a posttranscriptional mechanism for the regulation of CD40 surface expression. |