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 1 and 2, SAM50, CHCHD3, 
CHCHD6 and DnaJC11, 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 
1 and 2, SAM50 and CHCHD3) have been implicated in protein import, while DnaJC11 
is a chaperone-like protein that may have a similar role.