BEM1/YBR200W Summary Help

Standard Name BEM1 1
Systematic Name YBR200W
Alias SRO1
Feature Type ORF, Verified
Description 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 (2 and see Summary Paragraph)
Name Description Bud EMergence 1
Chromosomal Location
ChrII:620872 to 622527 | ORF Map | GBrowse
Genetic position: 102 cM
Gene Ontology Annotations All BEM1 GO evidence and references
  View Computational GO annotations for BEM1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 1 genes
Classical genetics
Large-scale survey
772 total interaction(s) for 472 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 9
  • Affinity Capture-RNA: 2
  • Affinity Capture-Western: 26
  • Biochemical Activity: 3
  • Co-crystal Structure: 2
  • Co-fractionation: 20
  • Co-purification: 8
  • PCA: 10
  • Protein-peptide: 11
  • Reconstituted Complex: 16
  • Two-hybrid: 65

Genetic Interactions
  • Dosage Growth Defect: 3
  • Dosage Lethality: 3
  • Dosage Rescue: 26
  • Negative Genetic: 427
  • Phenotypic Enhancement: 2
  • Phenotypic Suppression: 2
  • Positive Genetic: 66
  • Synthetic Growth Defect: 16
  • Synthetic Haploinsufficiency: 1
  • Synthetic Lethality: 46
  • Synthetic Rescue: 8

Expression Summary
Length (a.a.) 551
Molecular Weight (Da) 61,605
Isoelectric Point (pI) 9.18
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrII:620872 to 622527 | ORF Map | GBrowse
Genetic position: 102 cM
Last Update Coordinates: 2011-02-03 | Sequence: 1997-01-28
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1656 620872..622527 2011-02-03 1997-01-28
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000000404

Bem1p helps to establish the cellular polarity that is required for bud and shmoo formation. An excellent review written by Madden and Snyder describes the process of establishing cell polarity and morphogenesis in yeast (2).

Bem1p is an SH3-domain protein that binds Cdc24p, which is a nucleotide exchange factor for Cdc42p, a Rac/Rho GTPase. Because Bem1p also binds Ste5p and Ste20p, which are central components of the mating pathway, Bem1's role may be to connect the mating signal to the proteins that induce the appropriate changes to the actin cytoskeleton (3).

Bem1p, Cdc24p, and Cdc42p also interact with a GTPase complex that is involved in budding (4, 5). This GTPase complex consists of Rsr1/Bud1, a Ras-related GTPase, Bud2p, the GTPase activating protein (GAP), and Bud5p, the guanine-nucleotide exchange factor (GEF) (6, 7, 8). The function of the Rsr1 GTPase complex may be to localize Bem1p, Cdc24p, and Cdc42p at the nascent bud site where they can reorganize the actin cytoskeleton to establish polarization (9).

Last updated: 1999-10-20 Contact SGD

References cited on this page View Complete Literature Guide for BEM1
1) Bender A and Pringle JR  (1991) Use of a screen for synthetic lethal and multicopy suppressee mutants to identify two new genes involved in morphogenesis in Saccharomyces cerevisiae. Mol Cell Biol 11(3):1295-305
2) Madden K and Snyder M  (1998) Cell polarity and morphogenesis in budding yeast. Annu Rev Microbiol 52():687-744
3) Leeuw T, et al.  (1995) Pheromone response in yeast: association of Bem1p with proteins of the MAP kinase cascade and actin. Science 270(5239):1210-3
4) Johnson DI and Pringle JR  (1990) Molecular characterization of CDC42, a Saccharomyces cerevisiae gene involved in the development of cell polarity. J Cell Biol 111(1):143-52
5) Zheng Y, et al.  (1993) Biochemical comparisons of the Saccharomyces cerevisiae Bem2 and Bem3 proteins. Delineation of a limit Cdc42 GTPase-activating protein domain. J Biol Chem 268(33):24629-34
6) Bender A and Pringle JR  (1989) Multicopy suppression of the cdc24 budding defect in yeast by CDC42 and three newly identified genes including the ras-related gene RSR1. Proc Natl Acad Sci U S A 86(24):9976-80
7) Bender A  (1993) Genetic evidence for the roles of the bud-site-selection genes BUD5 and BUD2 in control of the Rsr1p (Bud1p) GTPase in yeast. Proc Natl Acad Sci U S A 90(21):9926-9
8) Park HO, et al.  (1993) BUD2 encodes a GTPase-activating protein for Bud1/Rsr1 necessary for proper bud-site selection in yeast. Nature 365(6443):269-74
9) Park HO, et al.  (1997) Two active states of the Ras-related Bud1/Rsr1 protein bind to different effectors to determine yeast cell polarity. Proc Natl Acad Sci U S A 94(9):4463-8