Protein Tyrosine Phosphatase, Non Receptor Type 5 (PTPN5)

Analyses of various regions of the rat brain demonstrated a 3-kb and a 4.4-kb mRNA. The 3-kb mRNA was highly enriched within the striatum relative to other brain areas and thus was termed 'striatum-enriched phosphatase' (STEP) by the authors. In contrast, the 4.4-kb message was most abundant in the cerebral cortex and rare in the striatum. These 2 messages appeared to be alternatively processed mRNA transcripts of a single gene. Sharma et al. (1995) isolated and characterized additional alternatively spliced transcripts of the STEP gene. STEP 46 is the full-length, 46-kD protein. STEP 20 did not have the conserved tyrosine phosphatase domain. STEP 61 has a 5-prime extended open reading frame that encodes a protein with a predicted molecular mass of 61 kD and contains a single tyrosine phosphatase domain.