Ptpn1
Function
Tyrosine-protein phosphatase which acts as a regulator of endoplasmic reticulum unfolded protein response. Mediates dephosphorylation of EIF2AK3/PERK; inactivating the protein kinase activity of EIF2AK3/PERK. May play an important role in CKII- and p60c-src-induced signal transduction cascades. May regulate the EFNA5-EPHA3 signaling pathway which modulates cell reorganization and cell-cell repulsion. May also regulate the hepatocyte growth factor receptor signaling pathway through dephosphorylation of MET (By similarity).
Post-translational modifications
Ser-50 is the major site of phosphorylation as compared to Ser-242 and Ser-243. Activated by phosphorylation at Ser-50 (By similarity).
S-nitrosylation of Cys-215 inactivates the enzyme activity.
Sulfhydration at Cys-215 following endoplasmic reticulum stress inactivates the enzyme activity, promoting EIF2AK3/PERK activity.
Sequence Similarities
Belongs to the protein-tyrosine phosphatase family. Non-receptor class 1 subfamily.
Tissue Specificity
Most abundant in testis. Also found in kidney, spleen, muscle, liver, heart and brain.
Cellular localization
- Endoplasmic reticulum membrane
- Peripheral membrane protein
- Cytoplasmic side
- Interacts with EPHA3 at the cell membrane.
Alternative names
Tyrosine-protein phosphatase non-receptor type 1, Protein-tyrosine phosphatase 1B, Protein-tyrosine phosphatase HA2, PTP-1B, PTP-HA2