Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.

Gene Ontology (GO)

Last modified April 10, 2018

The Gene Ontology (GO) project provides a set of hierarchical controlled vocabulary split into 3 categories:

  • Biological process
  • Molecular function
  • Cellular component

UniProtKB lists selected terms derived from the GO project. The GO terms derived from the 'Biological process' and Molecular function' categories are listed in the 'Function' section; the GO terms derived from the 'Cellular component' category are listed in the 'Subcellular location' section.

GO terms can be manually or electronically assigned to a UniProtKB entry:

  • Manually assigned GO terms found in UniProtKB/Swiss-Prot are associated with one of 15 GO evidence codes, as well as with a link to the relevant publication, when available. These GO annotations are tagged with a yellow source/evidence label.
  • Electronically assigned GO terms are found in UniProtKB/TrEMBL, but to some extent also in UniProtKB/Swiss-Prot, and are associated with the GO evidence code 'IEA', which means 'inferred from electronic annotation'. These GO annotations are tagged with a blue source/evidence label.

Note that many UniProtKB keywords are manually mapped to GO terms (see document 'Controlled vocabulary of keywords'), but the resulting GO annotations in UniProtKB appear with a blue label as "inferred from electronic annotation".

List of GO evidence codes found in UniProtKB

  • EXP: Inferred from Experiment
    Used when experimental results indicate a gene product's function, process involvement or subcellular location.
  • IBA: Inferred from Biological Aspect of Ancestor
    Used when an aspect of a descendent is inferred through the characterization of an aspect of a ancestral gene.
  • IC: Inferred by Curator
    Used when annotation is not supported by any evidence, but can be reasonably inferred by a curator from other GO annotations for which evidence is available.
  • IDA: Inferred from Direct Assay
    Used when a direct assay for the function, process or component indicated by the GO term is available.
  • HDA: High-throughput Direct Assay
  • IEA: Inferred from Electronic Annotation
    Used when annotation derives from computation or automated transfer from a database. These annotations have not been manually checked.
  • IEP: Inferred from Expression Pattern
    Used when annotation is inferred from the timing or site of expression of a gene.
  • HEP: High-throughput Expression Pattern
  • IGC: Inferred from Genomic Context
    Used when information about the genomic context of a gene product forms part of the evidence for a particular annotation. Genomic context includes, but is not limited to, such things as identity of neighboring genes (i.e. synteny), operon structure, and phylogenetic or other whole genome analysis.
  • IGI: Inferred from Genetic Interaction
    Used to describe "traditional" genetic interactions, such as suppressors and synthetic lethals, as well as other techniques, such as functional complementation, rescue experiments, or inferences about a gene drawn from the phenotype of a mutation in a different gene.
  • HGI: High-throughput Genetic Interaction
  • IMP: Inferred from Mutant Phenotype
    Used to describe the observations of variations or changes in a gene product, such as mutations or abnormal levels. This includes techniques, such as knockouts, overexpression, anti-sense experiments and use of specific protein inhibitors.
  • HMP: High-throughput Mutant Phenotype
  • IPI: Inferred from Physical Interaction
    Used to cover physical interactions between the gene product of interest and another molecule (ion, complex, etc.).
  • ISA: Inferred from Sequence Alignment
    Used when the primary piece of evidence is a pairwise or multiple sequence alignment.
  • ISM: Inferred from Sequence Model
    Used when any kind of sequence modeling method (e.g. Hidden Markov Models) is the primary piece of evidence
  • ISO: Inferred from Sequence Orthology
    Used when the assertion of orthology between the gene product and an experimentally characterized gene product in another organism is the main basis of the annotation
  • ISS: Inferred from Sequence or Structural Similarity
    Used for any analysis based on sequence alignment, structure comparison, or evaluation of sequence features, such as composition.
  • NAS: Non-traceable Author Statement
    Used for statements found in a published article that cannot be traced back to another publication.
  • TAS: Traceable Author Statement
    Used for information obtained from published articles, mostly reviews, as well as text books or dictionaries, where the original experiments are traceable.

Additional information: GO evidence codes

UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health

We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.

Do not show this banner again