cDNA cloning and characterization of a novel receptor-type protein XXXX phosphatase expressed predominantly in the brain.

@entity19 @entity669 @entity71219 @entity71220
Protein @entity669 phosphatase has the potential to control various cellular events by negatively regulating the extent of @entity669 phosphorylation. Here, we report the isolation of a @entity19 receptor protein @entity669 phosphatase, @entity71219 , which is expressed almost exclusively in the brain. Though the cytoplasmic portion of @entity71219 reveals high similarity to @entity71220 / @entity71220 and STEP, these are, unlike @entity71219 , non-receptor protein @entity669 phosphatases. Unlike most receptor protein @entity669 phosphatases, @entity71219 has only one cytoplasmic phosphatase domain, and its extracellular domain reveals no obvious structural similarity to known molecules. Thus, @entity71219 defines a new subfamily of receptor-type protein @entity669 phosphatases. The putative extracellular domain of @entity71219 was expressed in COS-7 cells as a chimeric fusion protein with an immunoglobulin Fc portion ( @entity71219 -Fc). @entity71219 -Fc was secreted in the culture supernatant, confirming the capability of the extracellular domain of @entity71219 to translocate across the cytoplasmic membrane. The cytoplasmic portion of @entity71219 was expressed as a fusion protein in bacteria and was demonstrated to have catalytic activity. The expression of @entity71219 was detectable in brain and especially in cerebellum but undetectable in liver, lung, heart, kidney, thymus, bone marrow, and spleen. In situ hybridization analysis revealed the most prominent signal in Purkinje cells. The predominant expression of @entity71219 in the brain suggests that @entity71219 may have role(s) in neuronal cells.
