This region of the Zds1 protein is critical for sporulation and has also been shown to suppress the calcium sensitivity of Zds1 deletions [1]. The C-terminal motif is common to both Zds1 and Zds2 proteins, both of which are putative interactors of Cdc55 and are required for the completion of mitotic exit and cytokinesis. They both contribute to timely Cdc14 activation during mitotic exit and are required downstream of separase to facilitate nucleolar Cdc14 release[2].

1: zds1, a novel gene encoding an ortholog of Zds1 and Zds2, controls sexual differentiation, cell wall integrity, and cell morphology in fission yeast. Yakura M, Ozoe F, Ishida H, Nakagawa T, Tanaka K, Matsuda H, Kawamukai M; Genetics. 2005; [Epub ahead of print] PMID:16322512

2: Separase cooperates with Zds1 and Zds2 to activate Cdc14 phosphatase in early anaphase. Queralt E, Uhlmann F; J Cell Biol. 2008;182:873-883. PMID:18762578