Abstract
Purpose: :
We previously reported that SNP rs10490924 at 10q26 within the ARMS2/LOC387715 gene is strongly associated with susceptibility to age-related macular degeneration (AMD) and that ARMS2 encodes a 12 kDa protein which localizes to mitochondrial outer membrane in transfected cells (Kanda et al. 2007 PNAS). We are interested in determining the function of the ARMS2 protein and identify the domain/region that is needed for its localization to mitochondria.
Methods: :
Missense and deletion mutations were generated in the ARMS2 protein by site-directed mutagenesis of a pcDNA4c expression construct. Wild type (WT) and mutant ARMS2 constructs were transfected into established cell cultures to examine cellular localization.
Results: :
The WT-ARMS2 construct revealed a single protein band by immunoblot analysis, and this protein was localized to the mitochondria. N-terminal deletion mutants did not affect mitochondria localization, whereas C-terminal deletions mislocalized the ARMS2 protein to the cytoplasm. Analysis of multiple mutants identified four amino acid residues in the C-terminal region that are required for mitochondrial localization of the ARMS2 protein.
Conclusions: :
Our results show that C-terminal region of the ARMS2 protein is critical for its subcellular localization and probably physiological function.
Keywords: age-related macular degeneration • mitochondria