Lyp: Proteins and Enzymes

Lyp, also called LyPTP, protein tyrosine phosphatase, nonreceptor-type 22, and PEST-domain phosphatase, dephosphorylates tyrosine residues in proteins. Found primarily in bone marrow and lymphoid cell lines, an R620W gain-of-function mutation in Lyp has been associated with susceptibility to autoimmune diseases such as type I diabetes, rheumatoid arthritis, and lupus erythematosus. Mature PEP knockout mice have an excess of CD8 positive T cells and an exaggerated antigen-induced proliferative response.