SWE1/YJL187C Summary Help

Standard Name SWE1 1
Systematic Name YJL187C
Alias WEE1
Feature Type ORF, Verified
Description Protein kinase that regulates the G2/M transition; regulates the G2/M transition by inhibition of Cdc28p kinase activity; localizes to the nucleus and to the daughter side of the mother-bud neck; phosphorylates conserved tyrosine residue in N-terminus of Hsp90 in cell-cycle associated manner, thus modulating the ability of Hsp90 to chaperone a selected clientele; homolog of S. pombe Wee1p; potential Cdc28p substrate (1, 2, 3, 4 and see Summary Paragraph)
Name Description Saccharomyces WEe1 1
Chromosomal Location
ChrX:79262 to 76803 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All SWE1 GO evidence and references
  View Computational GO annotations for SWE1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 10 genes
Classical genetics
Large-scale survey
457 total interaction(s) for 294 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 34
  • Affinity Capture-RNA: 1
  • Affinity Capture-Western: 22
  • Biochemical Activity: 124
  • Co-localization: 1
  • Protein-RNA: 1
  • Reconstituted Complex: 7
  • Two-hybrid: 21

Genetic Interactions
  • Dosage Growth Defect: 26
  • Dosage Lethality: 2
  • Dosage Rescue: 6
  • Negative Genetic: 90
  • Phenotypic Enhancement: 16
  • Phenotypic Suppression: 39
  • Positive Genetic: 7
  • Synthetic Growth Defect: 9
  • Synthetic Lethality: 16
  • Synthetic Rescue: 35

Expression Summary
Length (a.a.) 819
Molecular Weight (Da) 92,467
Isoelectric Point (pI) 6.22
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrX:79262 to 76803 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..2460 79262..76803 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 | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000003723

SWE1 (Saccharomyces Wee1) encodes a protein kinase involved in regulating the G2/M transition (1). Swe1p inhibits the kinase activity of the main cell-cycle cyclin-dependent kinase Cdc28p through phosphorylation of a conserved tyrosine residue, Y19 (1). Y19 phosphorylation is reversed by the phosphatase Mih1p, which is homologous to CDC25 in other organisms (5). Swe1p-mediated inhibition of Cdc28p is important for delaying mitosis until all appropriate conditions are met (6, 7), and appears to regulate Clb-Cdc28p complexes to different degrees depending on which B-type cyclin is involved (8). Swe1p is also important for delaying meiosis when the pachytene checkpoint is triggered (9). In addition to checkpoint functions, a Swe1p-mediated G2 delay is employed during filamentous growth to promote bud elongation and invasive growth (10). Swe1p may also be required for reentry into the cell cycle after a G1 arrest caused by defects in ribosome biogenesis or protein synthesis (11).

Swe1p expression is cell-cycle regulated, with accumulation beginning in S phase (12). As the cell cycle progresses, Swe1p undergoes a complex series of sequential phosphorylations by a variety of kinases, including Cdc5p, Cla4p, and Clb-Cdc28p, which result in hyperphosphorylation and subsequent ubiquitin-mediated degradation (6, 12). Swe1p abundance also increases transiently in response to ethanol stress (13).

swe1 null mutants display altered cell size and cell cycle kinetics (14, 15), and are hypersensitive to ethanol (13). Overexpression of Swe1p leads to a G2 arrest and in some strain backgrounds null mutants enter mitosis prematurely (15, 14, 1, 16). Homozygous diploid swe1 null mutants are able to complete multiple rounds of pre-meiotic DNA replication within a single cell cycle, which results in some cells displaying more than 4 spores in a single ascus (17). In pre-mitotic cells, Swe1p localizes to the nucleus and also to the daughter-side of the mother-bud neck where it may be marked for degradation (2).

Swe1p homologs have been identified in several organisms, including Schizosaccharomyces pombe (wee1), Xenopus (Xwee1) and humans (Wee1Hu), where they are required to govern entry into mitosis and to delay cell cycle progression in response to DNA damage (18, 19, 20, 21, and 22).

Last updated: 2005-09-12 Contact SGD

References cited on this page View Complete Literature Guide for SWE1
1) Booher RN, et al.  (1993) Properties of Saccharomyces cerevisiae wee1 and its differential regulation of p34CDC28 in response to G1 and G2 cyclins. EMBO J 12(9):3417-26
2) Longtine MS, et al.  (2000) Septin-dependent assembly of a cell cycle-regulatory module in Saccharomyces cerevisiae. Mol Cell Biol 20(11):4049-61
3) Ubersax JA, et al.  (2003) Targets of the cyclin-dependent kinase Cdk1. Nature 425(6960):859-64
4) Mollapour M, et al.  (2010) Swe1(Wee1)-Dependent Tyrosine Phosphorylation of Hsp90 Regulates Distinct Facets of Chaperone Function. Mol Cell 37(3):333-343
5) Russell P, et al.  (1989) Conservation of mitotic controls in fission and budding yeasts. Cell 57(2):295-303
6) Harvey SL, et al.  (2005) Cdk1-dependent regulation of the mitotic inhibitor Wee1. Cell 122(3):407-20
7) Gladfelter AS, et al.  (2005) Interplay between septin organization, cell cycle and cell shape in yeast. J Cell Sci 118(Pt 8):1617-28
8) Hu F and Aparicio OM  (2005) Swe1 regulation and transcriptional control restrict the activity of mitotic cyclins toward replication proteins in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 102(25):8910-5
9) Leu JY and Roeder GS  (1999) The pachytene checkpoint in S. cerevisiae depends on Swe1-mediated phosphorylation of the cyclin-dependent kinase Cdc28. Mol Cell 4(5):805-14
10) La Valle R and Wittenberg C  (2001) A role for the Swe1 checkpoint kinase during filamentous growth of Saccharomyces cerevisiae. Genetics 158(2):549-62
11) Saracino F, et al.  (2004) The yeast kinase Swe1 is required for proper entry into cell cycle after arrest due to ribosome biogenesis and protein synthesis defects. Cell Cycle 3(5):648-54
12) Asano S, et al.  (2005) Concerted mechanism of Swe1/Wee1 regulation by multiple kinases in budding yeast. EMBO J 24(12):2194-204
13) Kubota S, et al.  (2004) Effect of ethanol on cell growth of budding yeast: genes that are important for cell growth in the presence of ethanol. Biosci Biotechnol Biochem 68(4):968-72
14) Jorgensen P, et al.  (2002) Systematic identification of pathways that couple cell growth and division in yeast. Science 297(5580):395-400
15) Harvey SL and Kellogg DR  (2003) Conservation of mechanisms controlling entry into mitosis: budding yeast wee1 delays entry into mitosis and is required for cell size control. Curr Biol 13(4):264-75
16) Lew DJ  (2003) The morphogenesis checkpoint: how yeast cells watch their figures. Curr Opin Cell Biol 15(6):648-53
17) Rice LM, et al.  (2005) Loss of meiotic rereplication block in Saccharomyces cerevisiae cells defective in Cdc28p regulation. Eukaryot Cell 4(1):55-62
18) Sorger PK and Murray AW  (1992) S-phase feedback control in budding yeast independent of tyrosine phosphorylation of p34cdc28. Nature 355(6358):365-8
19) Amon A, et al.  (1992) Regulation of p34CDC28 tyrosine phosphorylation is not required for entry into mitosis in S. cerevisiae. Nature 355(6358):368-71
20) Morgan DO  (1997) Cyclin-dependent kinases: engines, clocks, and microprocessors. Annu Rev Cell Dev Biol 13():261-91
21) Michael WM and Newport J  (1998) Coupling of mitosis to the completion of S phase through Cdc34-mediated degradation of Wee1. Science 282(5395):1886-9
22) Rhind N and Russell P  (2001) Roles of the mitotic inhibitors Wee1 and Mik1 in the G(2) DNA damage and replication checkpoints. Mol Cell Biol 21(5):1499-508