Fission yeast Opy1 is an endogenous PI(4,5)P sensor that binds to the phosphatidylinositol 4-phosphate 5-kinase Its3.

Phosphoinositides (PIPs) are a dynamic family of lipids that execute diverse roles in cell biology. PIP levels are regulated by numerous enzymes, but our understanding of how these enzymes are controlled in space and time is incomplete. One role of the PIP phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P] is to anchor the cytokinetic ring (CR) to the plasma membrane (PM) in While examining potential PI(4,5)P-binding proteins for roles in CR anchoring, we identified the dual pleckstrin homology (PH) domain-containing protein Opy1.

Analysis of the contribution of phosphoinositides to medial septation in fission yeast highlights the importance of PI(4,5)P for medial contractile ring anchoring.

In Schizosaccharomyces pombe, loss of the plasma membrane PI4-kinase scaffold Efr3 leads to sliding of the cytokinetic ring (CR) away from the cell center during anaphase, implicating phosphoinositides (PIPs) in CR anchoring. However, whether other PIP regulators contribute to CR anchoring has not been investigated. Here we report that mutants of other PIP kinases and their regulators divide with off-center septa, similar to efr3∆.