| Primary Identifier | IPR029023 | Type | Domain |
| Short Name | Tensin_phosphatase |
| description | Tensins constitute an eukaryotic family of lipid phosphatases that are definedby the presence of two adjacent domains: a lipid phosphatase domain and aC2-like domain. The tensin-type C2 lacks the canonical Ca(2+) ligands found inclassical C2 domains, and in this respect it is similar tothe C2 domains of PKC-type [, ]. The tensin-type C2 domain can bindphospholipid membranes in a Ca(2+) independent manner []. In the tumorsuppressor protein PTEN, the best characterized member of the family, thelipid phosphatase domain was shown to specifically dephosphorylate the D3position of the inositol ring of the lipid second messenger,phosphatydilinositol-3-4-5-triphosphate (PIP3). The lipid phosphatase domaincontains the signature motif HCXXGXXR present in the active sites of proteintyrosine phosphatases (PTPs) and dual specificity phosphatases (DSPs).Furthermore, two invariant lysines are found only in the tensin-typephosphatase motif (HCKXGKXR) and are suspected to interact with the phosphategroup at position D1 and D5 of the inositol ring [, ].The crystal structure of the PTEN tumor suppressor has been solved []. The lipid phosphatase domain has a structure similar to thedual specificity phosphatase. However, PTEN has a largeractive site pocket that could be important to accomodate PI(3,4,5)P3. Thetensin-type C2 domain has a structure similar to the classical C2 domain thatmediates the Ca2+ dependent membrane recruitment of several signalingproteins. However the tensin-type C2 domain lacks two of the three conservedloops that bind Ca2+.Proteins known to contain a phosphatase and a C2 tensin-type domain are listed below:Tensin, a focal-adhesion molecule that binds to actin filaments. It may beinvolved in cell migration, cartilage development and in linking signaltransduction pathways to the cytoskeleton.Phosphatase and tensin homologue deleted on chromosome 10 protein (PTEN).It antagonizes PI 3-kinase signalling by dephosphorylating the 3-positionof the inositol ring of PI(3,4,5)P3 and thus inactivates downstreamsignalling. It plays major roles both during development and in the adultto control cell size, growth, and survival.Auxilin. It binds clathrin heavy chain and promotes its assembly intoregular cages.Cyclin G-associated kinase or auxilin-2. It is a potential regulator ofclathrin-mediated membrane trafficking.PTEN homologues in fungi have the tensin phosphatase domain, but they lack the C2 domain. .This entry represents the phosphatase domain. |
