[Role of the protein tyrosine phosphatase CD45 in signal transduction of hematopoietic cells]

Abstract

This review deals with the analysis of modern literature about structure, catalytical activity, biological role and practical usage of protein tyrosine phosphatase CD45, which is widely distributed in the membranes of hematopoietic cells. The enzyme location makes it a highly sensitive test for estimation of development of such pathological states as immunological and neoplastic diseases, malignant tumors and transplantation responses of tissue tearing away. Unequal enzyme isoforms expressed in various leucocyte cell lines at different stages of development and differentiation are typical of those species. The existence of multiple isoforms is not used only to determine various cell lines, but also causes existence of variable adhesion requirements resulting in local restriction of activity and changes in the substrate binding. There is no doubt that definition of substrate molecules, influence of proteintyrosinephosphatase CD45 translocation and regulation of its activity by other ligands are important questions. Solution of these problems will be useful for searching the correctional means of dysfunctions of the tissues, enriched with protein tyrosine phosphatase CD45.