Fission 1 (FIS1)

The balance between fission and fusion regulates the morphology of mitochondria. TTC11 is a component of a mitochondrial complex that promotes mitochondrial fission.

The deduced 152-amino acid protein contains a central leucine zipper, a coiled-coil region, and a C-terminal transmembrane domain. It also contains a region showing high interspecies homology and a putative tetratricopeptide repeat. Immunocytochemical analysis of HeLa cells detected endogenous FIS1 expression in mitochondria. Protease treatment indicated that FIS1 is expressed at the outer mitochondrial membrane. Transfection of a C-terminal truncated FIS1 resulted in cytoplasmic expression, indicating that the C terminus is required for mitochondrial localization.