PIF1 / YML061C Overview

Standard Name
PIF1 1 2
Systematic Name
TST1 10
Feature Type
ORF , Verified
DNA helicase, potent G-quadruplex DNA binder/unwinder; possesses strand annealing activity; promotes DNA synthesis during break-induced replication; involved in crossover recombination; works with Hrq1p to maintain telomere length homeostasis; translation from different start sites produces mitochondrial (DNA repair and recombination) and nuclear (catalytic inhibitor of telomerase) isoforms; mutations affect Zn, Fe homeostasis; regulated by Rad53p-dependent phosphorylation in rho0 cells 1 3 4 5 6 7 8 9 10 11 12
Name Description
Petite Integration Frequency 2
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.

PIF1/YML061C is located on the left arm of chromosome XIII between MFT1 THO complex subunit and OGG1 nuclear and mitochondrial glycosylase/lyase; coding sequence is 2580 nucleotides long with 23 SNPs, 4 of which cause amino acid polymorphisms
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.

Pif1p is 859 amino acids long, low in abundance; acetylated on 6 lysines, sumoylated on 4 lysines, phosphorylated on 19 residues
Length (a.a.)
Mol. Weight (Da)
Isoelectric Point
Median Abundance (molecules/cell)
1366 +/- 1105


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 PIF1 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.

DNA helicase and telomerase inhibitor; binds single-stranded DNA and G-quadruplex DNA; has multiple roles in chromosome organization including DNA strand renaturation, G-quadruplex DNA unwinding, and telomere maintenance; involved in DNA recombination, double-strand break repair via break-induced replication, and replication fork reversal; also involved in mitochondrial genome maintenance; localizes to the nucleus, replication fork, mitochondrion, and mitochondrial membrane

View computational annotations

Molecular Function

Manually Curated

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 mutant shows elevated frequency of mutations and gross chromosomal rearrangements; null mutant accumulates more iron than wild type in mitochondria and cytoplasm, and more zinc in mitochondria; null mutant is sensitive to DNA damaging agents and oxidative stress but resistant to Zn++; inheritance of the mitochondrial genome is defective in the null mutant; in large-scale studies, null mutant shows respiratory growth defect, small cell size, reduced competitive fitness in a variety of different media, lengthened telomeres, and altered resistance to various chemicals
Disease Details


Disease Annotations consist of three mandatory components: a gene product, a term from the Disease Ontology (DO) controlled vocabulary and an evidence code. SGD provides manually curated DO Annotations derived from the literature. Click "Disease Details" to view all Disease information and evidence for this locus as well as diseases it shares with other genes.

Yeast PIF1 is homologous to human PIF1, and has been used to study mutations found in patients with cancer and progeria

Manually Curated

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.

Pif1p interacts physically with proteins involved in DNA repair and DNA replication; PIF1 interacts genetically with genes involved in DNA repair

334 total interactions for 200 unique genes

Physical Interactions

  • Affinity Capture-MS: 11
  • Affinity Capture-RNA: 9
  • Affinity Capture-Western: 8
  • Biochemical Activity: 1
  • Co-crystal Structure: 1
  • Reconstituted Complex: 7

Genetic Interactions

  • Dosage Growth Defect: 40
  • Dosage Lethality: 5
  • Dosage Rescue: 4
  • Negative Genetic: 55
  • Phenotypic Enhancement: 62
  • Phenotypic Suppression: 40
  • Positive Genetic: 6
  • Synthetic Growth Defect: 25
  • Synthetic Lethality: 22
  • Synthetic Rescue: 38
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.

PIF1 promoter is bound by Yap5p in response to heat; PIF1 transcription is regulated by Sfp1p in response to stress; Pif1 protein activity is activated by Esa1p and deactivated by Rpd3p
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: 2024-07-05

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.