Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

Integral plasma membrane protein; required for axial budding in haploid cells; localizes to the incipient bud site and bud neck; glycosylated by Pmt4p; potential Cdc28p substrate.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

Bud emergence protein 1; Protein containing SH3-domains; involved in establishing cell polarity and morphogenesis; functions as a scaffold protein for complexes that include Cdc24p, Ste5p, Ste20p, and Rsr1p.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

GTPase-activating protein BEM2/IPL2; Rho GTPase activating protein (RhoGAP); involved in the control of cytoskeleton organization and cellular morphogenesis; required for bud emergence; potential GAP for Rho4p.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

Protein BNI1; Formin; polarisome component; nucleates the formation of linear actin filaments, involved in cell processes such as budding and mitotic spindle orientation which require the formation of polarized actin cables; recruited to the division site in a Glc7p/Ref2p dependent manner following release of Bnr1p; functionally redundant with BNR1.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

Protein implicated in polar growth, functionally redundant with Boi1p; interacts with bud-emergence protein Bem1p; contains an SH3 (src homology 3) domain and a PH (pleckstrin homology) domain; BOI2 has a paralog, BOI1, that arose from the whole genome duplication.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

Bud site selection protein 3; Guanine nucleotide exchange factor (GEF) for Cdc42p; activates Cdc42p in early G1, accounting for the first stage of biphasic activation, with Cdc24p accounting for the second stage in late G1; involved in the Cdc42p-mediated assembly of the axial landmark that dictates the site for the next round of budding, resulting in the axial budding pattern observed in haploids; localizes with septins to the bud neck contractile ring in mitosis.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

Cell division control protein 24; Guanine nucleotide exchange factor (GEF) for Cdc42p; required for polarity establishment and maintenance, and mutants have morphological defects in bud formation and shmooing; relocalizes from nucleus to cytoplasm upon DNA replication stress; thermosensitivity of the cdc24-4 mutant in the presence of sorbitol is functionally complemented by human CDC42.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

Cell division control protein 42; Small rho-like GTPase; essential for establishment and maintenance of cell polarity; plays a role late in cell fusion via activation of key cell fusion regulator Fus2p; mutants have defects in the organization of actin and septins; human homolog CDC42 can complement yeast cdc42 mutant.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

Serine/threonine-protein kinase CLA4; Cdc42p-activated signal transducing kinase; member of the PAK (p21-activated kinase) family, along with Ste20p and Skm1p; involved in septin ring assembly, vacuole inheritance, cytokinesis, sterol uptake regulation; phosphorylates Cdc3p and Cdc10p; CLA4 has a paralog, SKM1, that arose from the whole genome duplication.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

GTPase-interacting component 1; Protein involved in initiation of budding and cellular polarization; interacts with Cdc42p via the Cdc42/Rac-interactive binding (CRIB) domain; relocalizes from bud neck to nucleus upon DNA replication stress; GIC1 has a paralog, GIC2, that arose from the whole genome duplication.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

GTPase-interacting component 2; Redundant rho-like GTPase Cdc42p effector; involved in initiation of budding and cellular polarization; interacts with Cdc42p via the Cdc42/Rac-interactive binding (CRIB) domain and with PI(4,5)P2 via a polybasic region; GIC2 has a paralog, GIC1, that arose from the whole genome duplication.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

Ras GTPase-activating-like protein IQG1; Essential protein required for determination of budding pattern; promotes localization of axial markers Bud4p and Cdc12p and functionally interacts with Sec3p, localizes to the contractile ring during anaphase, member of the IQGAP family; relocalizes from bud neck to cytoplasm upon DNA replication stress.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

Guanine nucleotide exchange factor LTE1; Protein similar to GDP/GTP exchange factors; without detectable GEF activity; required for asymmetric localization of Bfa1p at daughter-directed spindle pole bodies and for mitotic exit at low temperatures.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

Rab GTPase-activating protein; regulates endocytosis via inactivation of Vps21p at endosomes and vacuole fusion via inactivation of Ypt7p at vacuoles; also acts on Ypt52p and Sec4p; localizes to plasma membrane, sites of polarized growth; relocalizes from bud neck to cytoplasm upon DNA replication stress; similar to TBC-domain Tre2 oncogene; MSB3 has a paralog, MSB4, that arose from the whole genome duplication; human homolog USP6NL can complement yeast msb3 msb4 double null.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

Ras-like protein 2; GTP-binding protein; regulates nitrogen starvation response, sporulation, and filamentous growth; farnesylation and palmitoylation required for activity and localization to plasma membrane; homolog of mammalian Ras proto-oncogenes; RAS2 has a paralog, RAS1, that arose from the whole genome duplication; Belongs to the small GTPase superfamily. Ras family.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

Rho GDP dissociation inhibitor; involved in the localization and regulation of Cdc42p and Rho1p; protein abundance increases in response to DNA replication stress.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

GTPase-activating protein for polarity-establishment protein Cdc42p; implicated in control of septin organization, pheromone response, and haploid invasive growth; relocalizes from bud neck to cytoplasm upon DNA replication stress; RGA1 has a paralog, RGA2, that arose from the whole genome duplication.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

GTPase-activating protein for polarity-establishment protein Cdc42p; implicated in control of septin organization, pheromone response, and haploid invasive growth; regulated by Pho85p and Cdc28p; RGA2 has a paralog, RGA1, that arose from the whole genome duplication.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

GTP-binding protein RHO3; Non-essential small GTPase of the Rho/Rac family of Ras-like proteins; involved in the establishment of cell polarity; GTPase activity positively regulated by the GTPase activating protein (GAP) Rgd1p.

Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions.

Ras-related protein RSR1; GTP-binding protein of the Ras superfamily; required for bud site selection, morphological changes in response to mating pheromone, and efficient cell fusion; localized to the plasma membrane; significantly similar to mammalian Rap GTPases.