INO4 / YOL108C Overview

Standard Name
Systematic Name
Feature Type
ORF , Verified
Transcription factor involved in phospholipid synthesis; required for derepression of inositol-choline-regulated genes involved in phospholipid synthesis; forms a complex, with Ino2p, that binds the inositol-choline-responsive element through a basic helix-loop-helix domain 1 2
Name Description
INOsitol requiring
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)
915 +/- 472
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.

View all INO4 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.

Component of sequence specific DNA-binding heteromeric transcription factor Ino2/Ino4p that activates transcription of genes involved in phospholipid metabolism

View computational annotations

Biological Process

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.

Non-essential gene; null mutant shows inositol auxotrophy and reduced synthesis of phosphatidylcholine
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.

1007 total interactions for 754 unique genes

Physical Interactions

  • Affinity Capture-MS: 15
  • Affinity Capture-RNA: 4
  • Affinity Capture-Western: 5
  • Co-localization: 2
  • Far Western: 1
  • Reconstituted Complex: 3
  • Two-hybrid: 17

Genetic Interactions

  • Negative Genetic: 613
  • Phenotypic Enhancement: 1
  • Positive Genetic: 327
  • Synthetic Growth Defect: 13
  • 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.

INO4 encodes a zipper-type transcription factor of the basic helix-loop-helix (bHLH) family that binds 5'-GCATGTGAAT-3' motifs, known as the inositol sensitive upstream activating elements (UAS-INO) or inositol/choline responsive elements (ICRE). Ino2p and Ino4p work as a heterodimer to activate transcription by binding ICREs in the promoters of structural genes of the phosphatidyl-inositol and phosphatidyl-choline synthesis pathways, including INO1 and more than 30 other genes. Regulation of the Ino2p/Ino4p heterodimer involves the Opi1p repressor, which interacts with transcription activation domains in Ino2p. When inositol is limiting, Opi1p directly interacts with phosphatidic acid and is tethered to the ER membrane, derepressing the Ino2p/Ino4p activatory heterodimer, which can then turn on transcription of its target genes. When phosphatidic acid levels are reduced, Opi1p is released from the ER membrane and enters the nucleus, where it prevents Ino2p/Ino4p from activating transcription by binding the activation domains in Ino2p.
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.