IFH1 / YLR223C Overview

Standard Name
IFH1 1
Systematic Name
Feature Type
ORF , Verified
Coactivator, regulates transcription of ribosomal protein (RP) genes; recruited to RP gene promoters during optimal growth conditions via Fhl1p; subunit of CURI, a complex that coordinates RP production and pre-rRNA processing; regulated by acetylation and phosphorylation at different growth states via TORC1 signaling; IFH1 has a paralog, CRF1, that arose from the whole genome duplication 1 2 3 4 5 6
Name Description
Interacts with Fork Head 1
CRF1 5
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.

IFH1 has a paralog, CRF1, that arose from the whole genome duplication
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)
1958 +/- 528
Half-life (min)


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.

View all IFH1 alleles in SGD search

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.

Transcription regulator involved in the positive regulation of ribosomal protein gene transcription and also telomeric silencing; subunit of CURI complex

View computational annotations

Molecular Function

Manually Curated

Cellular Component

Manually Curated


Macromolecular complex annotations are imported from the Complex Portal. These annotations have been derived from physical molecular interaction evidence extracted from the literature and cross-referenced in the entry, or by curator inference from information on homologs in closely related species or by inference from scientific background.

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.

Essential gene; overexpression slows growth, interferes with silencing, and increases production of ribosomal protein mRNAs; reduced function alleles increase lifespan, hamper growth and rRNA processing, reduce resistance to DNA damaging agents and TOR inhibitor rapamycin; heterozygous diploids are haploinsufficient
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 ifh1 null mutant is inviable; the null mutant of paralog crf1 is viable; the ifh1 crf1 double mutant has not been annotated for phenotype.

98 total interactions for 66 unique genes

Physical Interactions

  • Affinity Capture-MS: 33
  • Affinity Capture-RNA: 6
  • Affinity Capture-Western: 11
  • Biochemical Activity: 5
  • PCA: 2
  • Reconstituted Complex: 7
  • Two-hybrid: 20

Genetic Interactions

  • Dosage Growth Defect: 1
  • Dosage Lethality: 1
  • Dosage Rescue: 2
  • Negative Genetic: 2
  • Phenotypic Suppression: 1
  • Synthetic Growth Defect: 1
  • Synthetic Lethality: 2
  • Synthetic Rescue: 4
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.

IFH1 encodes a transcription coactivator that regulates genes involved in growth and metabolism. The complex of Ifh1p with the forkhead domain transcription factor Fhl1p activates transcription of nearly every ribosomal protein-encoding gene, as well as genes encoding a transcription factor (GCN4), translation factors, and metabolic enzymes (ADH2, ALD4, GDH1, MET6). Fhl1p is bound to target promoters at a relatively constant level, and recruitment of Ifh1p in response to growth conditions activates transcription. Modification of Ifh1p by various nutritional pathways serves to integrate nutritional signals. Stability of Ifh1p is regulated by acetylation in response to cellular levels of acetyl-CoA, mediated by the Gcn5p-containing SAGA complex. Ifh1p is deacetylated by the sirtuin family deacetylases Hst1p and Sir2p. Ifh1p is also phosphorylated by protein kinase A (PKA), and an ifh1 mutation that blocks phosphorylation confers an extended replicative lifespan. Both acetylation and phosphorylation levels of Ifh1p are regulated by the TORC1 complex. Ifh1p binding to Fhl1p is mutually exclusive with binding of the Ifh1p paralog Crf1p, which acts as a transcriptional corepressor for Fhl1p. In addition to binding Fhl1p, Ifh1p also forms a complex, termed CURI, that includes casein kinase Ckb2p and the rRNA processing factors Utp22p and Rrp7p. The CURI complex may help to couple regulation of ribosomal protein gene expression with regulation of rRNA production.
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.

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.