Required for establishment of the axial budding pattern in haploid cells. Cooperates with other bud site selection proteins to recognize a spatial landmark during mitosis and they subsequently become a landmark for downstream polarity establishment factors that coordinate axial budding and cytokinesis. Involved in the septin organization at the bud neck (By similarity). Interacts with AXL1, IQG1 and SEC3. Localizes to two distinct rings on either side of the mother-bud neck. The rings stay present in cells after cytokinesis and disappear before the next bud emergence. Requires IQG1 for proper localization (By similarity). Cell cycle-dependent with low levels at START and a peak in mitosis (at protein level). Phosphorylated by CDC28. Belongs to the BUD4 family.