Bud1

Bud1 is a gene that encodes a protein also known as Bud1. This gene plays a crucial role in cell polarity and the establishment of the bud site in the yeast Saccharomyces cerevisiae. Specifically, Bud1 is involved in the selection of the bud site, a process that ensures new daughter cells grow from a specific location on the parent cell. This spatial control is essential for proper cell division and morphology. The Bud1 protein is part of a complex that functions as a guanine nucleotide exchange factor (GEF) for the Rho GTPase Cdc42. By activating Cdc42, Bud1 helps to relay signals that direct the assembly of the actin cytoskeleton and the formation of the bud. Mutations in the Bud1 gene can lead to defects in budding, resulting in cells that are rounder and less polarized, with buds forming at random positions. This phenotype highlights the critical function of Bud1 in maintaining cell shape and directing growth. The study of Bud1 has provided significant insights into the molecular mechanisms underlying cell polarity and asymmetric division in eukaryotic cells.