ACT1/YFL039C Summary Help

Standard Name ACT1
Systematic Name YFL039C
Alias END7 , ABY1
Feature Type ORF, Verified
Description Actin; structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions (1, 2 and see Summary Paragraph)
Name Description ACTin
Chromosomal Location
ChrVI:54696 to 53260 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Genetic position: -59 cM
Gene Ontology Annotations All ACT1 GO evidence and references
  View Computational GO annotations for ACT1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 8 genes
Classical genetics
Large-scale survey
1020 total interaction(s) for 697 unique genes/features.
Physical Interactions
  • Affinity Capture-Luminescence: 2
  • Affinity Capture-MS: 134
  • Affinity Capture-RNA: 7
  • Affinity Capture-Western: 53
  • Biochemical Activity: 4
  • Co-crystal Structure: 2
  • Co-fractionation: 8
  • Co-localization: 9
  • Co-purification: 4
  • Far Western: 1
  • Protein-peptide: 1
  • Protein-RNA: 1
  • Reconstituted Complex: 62
  • Two-hybrid: 41

Genetic Interactions
  • Dosage Growth Defect: 7
  • Dosage Lethality: 3
  • Dosage Rescue: 8
  • Negative Genetic: 300
  • Phenotypic Enhancement: 2
  • Phenotypic Suppression: 5
  • Positive Genetic: 20
  • Synthetic Growth Defect: 31
  • Synthetic Haploinsufficiency: 261
  • Synthetic Lethality: 19
  • Synthetic Rescue: 35

Expression Summary
Length (a.a.) 375
Molecular Weight (Da) 41,689
Isoelectric Point (pI) 5.51
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrVI:54696 to 53260 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Genetic position: -59 cM
Last Update Coordinates: 2011-02-03 | Sequence: 2011-02-03
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..10 54696..54687 2011-02-03 1996-07-31
Intron 11..319 54686..54378 2011-02-03 2011-02-03
CDS 320..1437 54377..53260 2001-05-29 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 SGDIDS000001855

ACT1 encodes the single essential gene for actin (3, 2, 4). Actin is a ubiquitous, conserved cytoskeletal element critical for many cellular processes. The large collection of act1 mutants typically display defective intracellular actin distribution and show a wide diversity of phenotypes including: temperature sensitivity, osmotic sensitivity, ion concentration sensitivity, delocalized chitin deposition, a variety of gross morphological defects, abnormal nuclear segregation and/or cytokinesis, bud-site selection defects in diploids, alterations in organization and distribution of intracellular organelles, and a variety of secretion/endocytosis defects (reviewed in 5), reflecting the numerous functions of the actin cytoskeleton.

Actin is an ATP-binding protein that exists both in monomeric (G-actin) and filamentous (F-actin) forms (reviewed in 1, 6). Actin filaments are assembled by the reversible polymerization of monomers and have an intrinsic polarity; the fast-growing end is called the barbed end and the slow-growing end is called the pointed end. Yeast cells contain three types of filamentous actin structures: actin cables, an actin-myosin contractile ring, and actin cortical patches, all of which undergo extensive reorganization throughout the cell cycle (reviewed in 1, 6). Actin patches appear by fluorescence microscopy as cortical puncta, and are highly motile structures comprised of actin filaments that undergo rapid turnover (7). Actin patch assembly depends upon the actin-nucleating Arp2/3 complex (8). Actin patches are implicated in maintaining cell polarity, cell wall integrity, and endocytotic internalization (9, 1, 6, 10, 11). Actin cables are aligned with the mother-bud axis and are composed of bundles of actin filaments. Actin cables serve as tracks for polarized secretion, organelle and mRNA transport, and mitotic spindle alignment (12). The assembly of actin cables is dependent on the functionally redundant formins, Bni1p and Bnr1p (13, 14). The actin-myosin contractile ring forms transiently at the mother-daughter neck and is important for cytokinesis (reviewed in 15). Genetic screens and biochemical purifications have been fruitful in identifying numerous factors that regulate actin cytoskeleton dynamics, organization, and function (reviewed in 5, 1, 6).

Last updated: 2003-11-25 Contact SGD

References cited on this page View Complete Literature Guide for ACT1
1) Pruyne D and Bretscher A  (2000) Polarization of cell growth in yeast. J Cell Sci 113 ( Pt 4):571-85
2) Gallwitz D and Seidel R  (1980) Molecular cloning of the actin gene from yeast Saccharomyces cerevisiae. Nucleic Acids Res 8(5):1043-59
3) Ng R and Abelson J  (1980) Isolation and sequence of the gene for actin in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 77(7):3912-6
4) Shortle D, et al.  (1982) Lethal disruption of the yeast actin gene by integrative DNA transformation. Science 217(4557):371-3
5) Botstein D, et al.  (1997) "The yeast cytoskeleton." Pp. 1-90 in The Molecular and Cellular Biology of the Yeast Saccharomyces: Cell Cycle and Cell Biology, edited by Pringle JR, Broach JR and Jones EW. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press
6) Pruyne D and Bretscher A  (2000) Polarization of cell growth in yeast. I. Establishment and maintenance of polarity states. J Cell Sci 113 ( Pt 3):365-75
7) Ayscough KR, et al.  (1997) High rates of actin filament turnover in budding yeast and roles for actin in establishment and maintenance of cell polarity revealed using the actin inhibitor latrunculin-A. J Cell Biol 137(2):399-416
8) Winter D, et al.  (1997) The complex containing actin-related proteins Arp2 and Arp3 is required for the motility and integrity of yeast actin patches. Curr Biol 7(7):519-29
9) Munn AL  (2001) Molecular requirements for the internalisation step of endocytosis: insights from yeast. Biochim Biophys Acta 1535(3):236-57
10) Kilmartin JV and Adams AE  (1984) Structural rearrangements of tubulin and actin during the cell cycle of the yeast Saccharomyces. J Cell Biol 98(3):922-33
11) Kaksonen M, et al.  (2003) A pathway for association of receptors, adaptors, and actin during endocytic internalization. Cell 115(4):475-87
12) Schott D, et al.  (2002) Microfilaments and microtubules: the news from yeast. Curr Opin Microbiol 5(6):564-74
13) Evangelista M, et al.  (2002) Formins direct Arp2/3-independent actin filament assembly to polarize cell growth in yeast. Nat Cell Biol 4(3):260-9
14) Sagot I, et al.  (2002) Yeast formins regulate cell polarity by controlling the assembly of actin cables. Nat Cell Biol 4(1):42-50
15) Tolliday N, et al.  (2001) Assembly and regulation of the cytokinetic apparatus in budding yeast. Curr Opin Microbiol 4(6):690-5