FKH2 / YNL068C Overview

Standard Name
FKH2 1
Systematic Name
Feature Type
ORF , Verified
Forkhead family transcription factor; rate-limiting activator of replication origins; evolutionarily conserved regulator of lifespan; binds multiple chromosomal elements with distinct specificities, cell cycle dynamics; positively regulates transcriptional elongation; facilitates clustering, activation of early-firing replication origins; negative role in chromatin silencing at HML and HMR; major role in expression of G2/M phase genes; relocalizes to cytosol under hypoxia 1 2 3 4 5 6 7 8 9 10 11 12
Name Description
ForK head Homolog 1
FKH1 7
Comparative Info
Sequence Details


The S. cerevisiae Reference Genome sequence is derived from laboratory strain S288C. Download DNA or protein sequence, view genomic context and coordinates. Click "Sequence Details" to view all sequence information for this locus, including that for other strains.

Protein Details


Basic sequence-derived (length, molecular weight, isoelectric point) and experimentally-determined (median abundance, median absolute deviation) protein information. Click "Protein Details" for further information about the protein such as half-life, abundance, domains, domains shared with other proteins, protein sequence retrieval for various strains, physico-chemical properties, protein modification sites, and external identifiers for the protein.

Length (a.a.)
Mol. Weight (Da)
Isoelectric Point
Median Abundance (molecules/cell)
1507 +/- 808
Half-life (hr)


Curated mutant alleles for the specified gene, listed alphabetically. Click on the allele name to open the allele page. Click "SGD search" to view all alleles in search results. Click "YeastMine" to view all alleles in YeastMine.

View all FKH2 alleles in SGD search | YeastMine

Gene Ontology Details

Gene Ontology

GO Annotations consist of four mandatory components: a gene product, a term from one of the three Gene Ontology (GO) controlled vocabularies (Molecular Function, Biological Process, and Cellular Component), a reference, and an evidence code. SGD has manually curated and high-throughput GO Annotations, both derived from the literature, as well as computational, or predicted, annotations. Click "Gene Ontology Details" to view all GO information and evidence for this locus as well as biological processes it shares with other genes.

RNA polymerase II transcription factor involved in positive and negative regulation of transcription during mitotic cell cycle; positively regulates DNA replication initiation; binds replication origins and promoters in sequence-specific manner; localizes to cytosol and nucleus

View computational annotations

Cellular Component

Manually Curated
Phenotype Details


Phenotype annotations for a gene are curated single mutant phenotypes that require an observable (e.g., "cell shape"), a qualifier (e.g., "abnormal"), a mutant type (e.g., null), strain background, and a reference. In addition, annotations are classified as classical genetics or high-throughput (e.g., large scale survey, systematic mutation set). Whenever possible, allele information and additional details are provided. Click "Phenotype Details" to view all phenotype annotations and evidence for this locus as well as phenotypes it shares with other genes.

Non-essential gene; null mutants have abnormal vacuolar and spindle morphology, altered nuclear position, increased silencing at mating-type loci; nulls are also sensitive to anoxia, more easily form biofilms, and exhibit slow cell cycle progression and a G2/M phase delay; overexpression slows vegetative growth and decreases pseudohyphal growth under nitrogen starvation
Interaction Details


Interaction annotations are curated by BioGRID and include physical or genetic interactions observed between at least two genes. An interaction annotation is composed of the interaction type, name of the interactor, assay type (e.g., Two-Hybrid), annotation type (e.g., manual or high-throughput), and a reference, as well as other experimental details. Click "Interaction Details" to view all interaction annotations and evidence for this locus, including an interaction visualization.

The fkh2 null mutant is viable; the null mutant of paralog fkh1 is viable; the fkh2 fkh1 double mutant is inviable.

302 total interactions for 208 unique genes

Physical Interactions

  • Affinity Capture-MS: 19
  • Affinity Capture-RNA: 6
  • Affinity Capture-Western: 12
  • Biochemical Activity: 4
  • Co-localization: 1
  • Co-purification: 1
  • PCA: 2
  • Protein-RNA: 1
  • Proximity Label-MS: 1
  • Reconstituted Complex: 10
  • Two-hybrid: 2

Genetic Interactions

  • Dosage Growth Defect: 11
  • Dosage Rescue: 2
  • Negative Genetic: 158
  • Phenotypic Enhancement: 11
  • Phenotypic Suppression: 7
  • Positive Genetic: 37
  • Synthetic Growth Defect: 9
  • Synthetic Lethality: 5
  • Synthetic Rescue: 3
Regulation Details


The number of putative Regulators (genes that regulate it) and Targets (genes it regulates) for the given locus, based on experimental evidence. This evidence includes data generated through high-throughput techniques. Click "Regulation Details" to view all regulation annotations, shared GO enrichment among regulation Targets, and a regulator/target diagram for the locus.

FKH2 encodes a winged-helix/forkhead (FOX) family transcription factor involved in regulation of the mitotic cell cycle. Fkh2p shares sequence similarity and partially redundant functions with another forkhead family transcription factor, Fkh1p. Both proteins regulate a set of about 35 genes of the G2/M gene cluster, also referred to as the CLB2 cluster, which are expressed during the late S/G2-phase and control the cell cycle progression into the M phase. The G2/M cluster includes genes encoding the B-type cyclins Clb2p and Clb1p, the polo-like kinase Cdc5p, the APC/C specificity subunit Cdc20p and the transcription factors Ace2p and Swi5p. In the promoters of these genes, Fkh2p binds the sequence (5'-GTAAACAAA-3') adjacent to a binding site for the MADS box transcription factor Mcm1p. Mcm1p and Fkh2p together repress transcription of the G2/M cluster during the S phase, until Fkh2p associates with the coactivator Ndd1p, which activates transcription of the G2/M cluster. When Clb2p and Cdc5p are produced, they phosphorylate Ndd1p, which further stimulates binding of Ndd1p to Fkh2p and transcriptional activation, as cells enter the M phase. During the M phase, Clb2p-Cdc28p complex activates the APC/C-Cdh1p ubiquitin ligase, which targets Ndd1p for degradation, shutting off the transcription of the G2/M cluster and allowing cells to exit the M phase. FKH2 and NDD1 are themselves regulated by yet another forkhead family transcription factor, Hcm1p, which activates their expression during the S phase.
Expression Details


Expression data are derived from records contained in the Gene Expression Omnibus (GEO), and are first log2 transformed and normalized. Referenced datasets may contain one or more condition(s), and as a result there may be a greater number of conditions than datasets represented in a single clickable histogram bar. The histogram division at 0.0 separates the down-regulated (green) conditions and datasets from those that are up-regulated (red). Click "Expression Details" to view all expression annotations and details for this locus, including a visualization of genes that share a similar expression pattern.

Summary Paragraph

A summary of the locus, written by SGD Biocurators following a thorough review of the literature. Links to gene names and curated GO terms are included within the Summary Paragraphs.

Last Updated: 2016-03-23

Literature Details


All manually curated literature for the specified gene, organized into topics according to their relevance to the gene (Primary Literature, Additional Literature, or Review). Click "Literature Details" to view all literature information for this locus, including shared literature between genes.