LAS17/YOR181W Summary Help

Standard Name LAS17 1
Systematic Name YOR181W
Alias BEE1 2
Feature Type ORF, Verified
Description Actin assembly factor; C-terminal WCA domain activates Arp2/3 complex-mediated nucleation of branched actin filaments and a polyproline domain which can nucleate actin filaments independent of Arp2/3; mutants are defective in actin cytoskeleton dependent processes such as: endocytosis, bud site selection and cytokinesis; localizes with the Arp2/3 complex to actin cortical patches; homolog of the Wiskott-Aldrich Syndrome protein (WASP), implicated in severe immunodeficiency (1, 2, 3, 4, 5 and see Summary Paragraph)
Chromosomal Location
ChrXV:675939 to 677840 | ORF Map | GBrowse
Gene Ontology Annotations All LAS17 GO evidence and references
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 5 genes
Classical genetics
Large-scale survey
reduction of function
358 total interaction(s) for 156 unique genes/features.
Physical Interactions
  • Affinity Capture-Luminescence: 3
  • Affinity Capture-MS: 134
  • Affinity Capture-RNA: 1
  • Affinity Capture-Western: 36
  • Biochemical Activity: 8
  • Co-fractionation: 2
  • Co-localization: 2
  • Co-purification: 1
  • Far Western: 1
  • PCA: 15
  • Protein-peptide: 12
  • Reconstituted Complex: 6
  • Two-hybrid: 72

Genetic Interactions
  • Dosage Growth Defect: 3
  • Dosage Lethality: 2
  • Dosage Rescue: 10
  • Negative Genetic: 6
  • Phenotypic Enhancement: 7
  • Phenotypic Suppression: 9
  • Synthetic Growth Defect: 6
  • Synthetic Haploinsufficiency: 1
  • Synthetic Lethality: 19
  • Synthetic Rescue: 2

Expression Summary
Length (a.a.) 633
Molecular Weight (Da) 67,571
Isoelectric Point (pI) 10.05
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXV:675939 to 677840 | ORF Map | GBrowse
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1902 675939..677840 2011-02-03 1996-07-31
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 SGDIDS000005707

Las17p/Bee1p is an activator of the Arp2/3 protein complex that nucleates branched actin filaments. It is the only S. cerevisiae homolog of the human Wiskott-Aldrich syndrome protein (WASP) (6, 2) and is a member of the larger WASP/SCAR/WAVE protein family. Las17p was identified biochemically as an essential nucleation factor in the reconstitution of cortical actin patches in vitro, and independently as a verprolin (Vrp1p/End5p)-interacting protein (7, 1). Las17p localizes with the Arp2/3 complex to actin patches, and disruption of LAS17 leads to the loss of actin patches and a block in endocytosis (2, 1, 3).

Las17p physically interacts with the Arp2/3 complex. This interaction requires the carboxy-terminal WA (WH2 [WASp homology 2] and A[acidic]) domain of Las17p and is dependent upon two subunits of the Arp2/3 complex, Arc15p and Arc19p (4). The WA domain is sufficient for Arp2/3 complex binding and activation in vitro (4). The WA domain shares sequence similarity and genetic redundancy with an acidic domain in myosin I (Myo3p and Myo5p in S. cerevisiae), which also interacts with the Arp2/3 complex (8). These proteins appear to function redundantly in the activation of the Arp2/3 complex, as combined deletions of the WA domain of Las17p and the type I myosins abolish actin nucleation at cortical actin patches (6).

Genetic and biochemical studies have identified numerous proteins that physically interact with Las17p. The WH1 domain of Las17p binds strongly to verprolin (Vrp1p/End5p), the yeast homolog of human WIP (WASP-interacting protein), which is involved in Las17p localization (9, 10). The proline-rich region of Las17p binds to SH3 domain-containing proteins, including Sla1p (an actin patch protein with a role in endocytosis), Bbc1p/Mti1p, Bzz1p/Lsb7p, Myo3p, Myo5p, Lsb1p, Lsb2p, Ysc84p, Sho1p, and Rvs167p (11, 2, 3, 12, 6, 13). Although the significance of many of these interactions is not known, they may regulate the activity of Las17p, and thus, the activity of the Arp2/3 complex. Unlike other WASP family members, Las17p does not contain a conserved Cdc42p-binding domain and does not appear to be regulated by auto-inhibition (11).

Last updated: 2003-12-19 Contact SGD

References cited on this page View Complete Literature Guide for LAS17
1) Naqvi SN, et al.  (1998) The WASp homologue Las17p functions with the WIP homologue End5p/verprolin and is essential for endocytosis in yeast. Curr Biol 8(17):959-62
2) Li R  (1997) Bee1, a yeast protein with homology to Wiscott-Aldrich syndrome protein, is critical for the assembly of cortical actin cytoskeleton. J Cell Biol 136(3):649-58
3) Madania A, et al.  (1999) The Saccharomyces cerevisiae homologue of human Wiskott-Aldrich syndrome protein Las17p interacts with the Arp2/3 complex. Mol Biol Cell 10(10):3521-38
4) Winter D, et al.  (1999) Activation of the yeast Arp2/3 complex by Bee1p, a WASP-family protein. Curr Biol 9(9):501-4
5) Urbanek AN, et al.  (2013) A novel actin-binding motif in Las17/WASP nucleates actin filaments independently of Arp2/3. Curr Biol 23(3):196-203
6) Lechler T, et al.  (2000) Direct involvement of yeast type I myosins in Cdc42-dependent actin polymerization. J Cell Biol 148(2):363-73
7) Lechler T and Li R  (1997) In vitro reconstitution of cortical actin assembly sites in budding yeast. J Cell Biol 138(1):95-103
8) Evangelista M, et al.  (2000) A role for myosin-I in actin assembly through interactions with Vrp1p, Bee1p, and the Arp2/3 complex. J Cell Biol 148(2):353-62
9) Lechler T, et al.  (2001) A two-tiered mechanism by which Cdc42 controls the localization and activation of an Arp2/3-activating motor complex in yeast. J Cell Biol 155(2):261-70
10) Vaduva G, et al.  (1997) Actin-binding verprolin is a polarity development protein required for the morphogenesis and function of the yeast actin cytoskeleton. J Cell Biol 139(7):1821-33
11) Rodal AA, et al.  (2003) Negative regulation of yeast WASp by two SH3 domain-containing proteins. Curr Biol 13(12):1000-8
12) Drees BL, et al.  (2001) A protein interaction map for cell polarity development. J Cell Biol 154(3):549-71
13) Tong AH, et al.  (2002) A combined experimental and computational strategy to define protein interaction networks for peptide recognition modules. Science 295(5553):321-4