tyrosine-protein phosphatase 5, non-receptor type; protein-tyrosine phosphatase striatum-enriched; STEP; neural-specific protein-tyrosine phosphatase (PTPN5)

Function

• protein-tyrosine phosphatase
• may regulate activity of several effector molecules involved in synaptic plasticity & neuronal cell survival, including MAPKs, Src family kinases, focal adhesion kinase 2, NMDA receptors & AMPA receptors
• phosphorylation at Ser-245 by PKA deactivates PTPN5
• phosphorylation at Thr-255 & Ser-268 by MAPKs stabilizes the phosphatase
  • dephosphorylation of these sites results in ubiquitin- mediated degradation of the active phosphatase

Structure

• belongs to the protein-tyrosine phosphatase family non-receptor class subfamily
• contains 1 tyrosine-protein phosphatase domain

Compartment

• endoplasmic reticulum membrane
• multi-pass membrane protein (putative)

Alternative splicing

named isoforms=3

Pathology

• overactive in several neuropsychiatric & neurodegenerative disorders, including Alzheimer's disease

Comparative biology

• inhibitor of PTPN5/STEP improves cognitive function in a mouse model with no change in beta amyloid or phospho-tau levels

Notes

• uncertain whether Met-1 or Met-25 is the initiator

More general terms

• tyrosine phosphatase, non-receptor type

Database

• OMIM: https://mirror.omim.org/entry/176879
• UniProt: http://www.uniprot.org/uniprot/P54829.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=84867