This family is required for activation of the spg1 GTPase signalling cascade which leads to the initiation of septation and the subsequent termination of mitosis. It may act as a scaffold at the spindle pole body to which other components of the spg1 signalling cascade attach in pombe [1,2,3]. In S.cerevisiae it is both required for the proper formation of the spindle pole body outer plaque and may also connect the outer plaque to the central plaque embedded in the nuclear envelope [4].

1: Sid4p is required to localize components of the septation initiation pathway to the spindle pole body in fission yeast. Chang L, Gould KL; Proc Natl Acad Sci U S A. 2000;97:5249-5254. PMID:10805785

2: S. pombe cdc11p, together with sid4p, provides an anchor for septation initiation network proteins on the spindle pole body. Krapp A, Schmidt S, Cano E, Simanis V; Curr Biol. 2001;11:1559-1568. PMID:11676915

3: Sid4p-Cdc11p assembles the septation initiation network and its regulators at the S. pombe SPB. Morrell JL, Tomlin GC, Rajagopalan S, Venkatram S, Feoktistova AS, Tasto JJ, Mehta S, Jennings JL, Link A, Balasubramanian MK, Gould KL; Curr Biol. 2004;14:579-584. PMID:15062098

4: Cnm67p is a spacer protein of the Saccharomyces cerevisiae spindle pole body outer plaque. Schaerer F, Morgan G, Winey M, Philippsen P; Mol Biol Cell. 2001;12:2519-2533. PMID:11514632