Sfi1 Homolog (SFI1)

The deduced 968-amino acid protein had an apparent molecular mass of over 100 kD by SDS-PAGE. RT-PCR detected SFI1 in all tissues examined.The deduced 968- and 1,242-amino acid proteins have a central domain made up of imperfect repeats of 33 to 37 amino acids each. The full-length protein has 23 repeats. The repeat region shares a high degree of similarity with yeast Sfi1, but there is no homology between the N- and C-terminal domains. Both human fluorescence-tagged SFI1 isoforms localized close to centrioles in transfected HeLa cells. In yeast, Sfi1 localized to the half-bridge of the spindle pole body.Yeast Sfi1 mutants showed defective spindle pole body duplication and interaction with Cdc31, suggesting that, in addition to CDC31, SFI1 is essential for spindle pole body duplication.