Involvement of tyrosine phosphatase CD45 in apoptosis.
CD45 is a transmembrane molecule with phosphatase activity expressed in all nucleated haematopoietic cells and plays a major role in immune cells. It is a protein tyrosine phosphatase that is essential for antigen-receptor-mediated signal transduction by regulating Src family members that initiate TCR signaling. CD45 is being attributed a new emerging role as an apoptosis regulator. Cross-linking of the extracellular portion of the CD45 by monoclonal antibodies and by galectin-1, can induce apoptosis in T and B cells. Interestingly, this phosphatase has also been involved in nuclear apoptosis induced by mitochondrial perturbing agents. Furthermore, it is involved in apoptosis induced by HIV-1. CD45 defect is implicated in various diseases such as severe-combined immunodeficiency disease (SCID), acquired immunodeficiency syndrome (AIDS), lymphoma and multiple myelomas. The understanding of the mechanisms by which CD45 regulates apoptosis would be very useful in disease treatment.
INRS-Institut Armand-Frappier, 531 boul. des Prairies, Laval, QC H7V 1B7, Canada.
Geneviève
G
Dupéré-Minier
Philippe
P
Desharnais
Jacques
J
Bernier
D000818:Animals; D017209:Apoptosis; D006801:Humans; D017493:Leukocyte Common Antigens / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D008214:Lymphocytes / Q000166:cytology* / Q000276:immunology; D020033:Protein Isoforms
D020033:Protein Isoforms; D017493:Leukocyte Common Antigens