Tensins constitute an eukaryotic family of lipid phosphatases that are defined by the presence of two adjacent domains: a lipid phosphatase domain and a C2-like domain. The tensin-type C2 domain has a structure similar to the classical C2 domain (see IPR000008 ) that mediates the Ca2+-dependent membrane recruitment … expand

Tensins constitute an eukaryotic family of lipid phosphatases that are defined by the presence of two adjacent domains: a lipid phosphatase domain and a C2-like domain. The tensin-type C2 domain has a structure similar to the classical C2 domain (see IPR000008 ) that mediates the Ca2+-dependent membrane recruitment of several signalling proteins. However the tensin-type C2 domain lacks two of the three conserved loops that bind Ca2+, and in this respect it is similar to the C2 domains of PKC-type [ PUBMED:11395408 PUBMED:11858936 ]. The tensin-type C2 domain can bind phopholipid membranes in a Ca2+ independent manner [ PUBMED:10555148 ]. In the tumour suppressor protein PTEN, the best characterised member of the family, the lipid phosphatase domain was shown to specifically dephosphorylate the D3 position of the inositol ring of the lipid second messenger, phosphatydilinositol-3-4-5-triphosphate (PIP3). The lipid phosphatase domain contains the signature motif HCXXGXXR present in the active sites of protein tyrosine phosphatases (PTPs) and dual specificity phosphatases (DSPs). Furthermore, two invariant lysines are found only in the tensin-type phosphatase motif (HCKXGKXR) and are suspected to interact with the phosphate group at position D1 and D5 of the inositol ring [ PUBMED:11395408 PUBMED:10555148 ].