The mitochondrial inner membrane protein mitofilin exists as a complex with SAM50, metaxins 1 and 2, coiled-coil-helix coiled-coil-helix domain-containing protein 3 and 6 and DnaJC11

A monoclonal antibody (mAb) has been produced which reacts with human mitofilin, a mitochondrial inner membrane protein. This mAb immunocaptures its target protein in association with six other proteins, metaxins I and 2, SAM50, CHCHD3, CHCHD6 and DnaJCI 1, respectively. The first three are outer membrane proteins, CHCHD3 has been assigned to the matrix space, and the other two proteins have not been described in mitochondria previously. The functional role of this new complex is uncertain. However, a role in protein import related to maintenance of mitochondrial structure is suggested as mitofilin helps regulate mitochondrial morphology and at least four of the associated proteins (metaxins I and 2, SAM50 and CHCHD3) have been implicated in protein import, while DnaJCI I is a chaperone-like protein that may have a similar role. (c) 2007 Federation of European Biochemical Societies. Published by Elsevier BN. All rights reserved.