This is a family of fungal spindle pole body proteins that play a role in spindle body duplication. They contain binding sites for calmodulin-like proteins called centrins [1] which are present in microtubule-organising centres.

1: Sfi1p has conserved centrin-binding sites and an essential function in budding yeast spindle pole body duplication. Kilmartin JV; J Cell Biol 2003;162:1211-1221. PMID:14504268