Septins are GTPases involved in cytokinesis that assemble into filaments and form a ring at the cleavage site. May act by recruiting MYO1 and HOF1, a protein involved in septation, to the site of cleavage. Septins are also involved in cell morphogenesis, bud site selection, chitin deposition, cell cycle regulation, cell compartmentalization and spore wall formation (By similarity). Interacts with other septin proteins such as SPR28 to form a ring at the bud neck. Present at the bud neck during cell division. Probably interacts with phosphoinosides such as phosphatidylinositol 4-phosphate or phosphatidylinositol 5-phosphate (By similarity). Localized to the leading edges of the membrane sacs that form near the spindle-pole bodies and gradually extend to engulf the nuclear lobes that contain the haploid chromosome sets, thus forming the spores. Sporulation-specific. Belongs to the TRAFAC class TrmE-Era-EngA-EngB-Septin-like GTPase superfamily. Septin GTPase family.