InnateDB: Systems Biology of the Innate Immune Response

Homo sapiens Protein: TOP1

Summary

InnateDB Protein

IDBP-75141.6

Last Modified

2014-10-13 [Report errors or provide feedback]

Gene Symbol

TOP1

Protein Name

topoisomerase (DNA) I

Synonyms

TOPI;

Species

Homo sapiens

Ensembl Protein

ENSP00000354522

InnateDB Gene

IDBG-75139 (TOP1)

Protein Structure

UniProt Annotation

Function

Releases the supercoiling and torsional tension of DNA introduced during the DNA replication and transcription by transiently cleaving and rejoining one strand of the DNA duplex. Introduces a single-strand break via transesterification at a target site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(3'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 5'-OH DNA strand. The free DNA strand then undergoes passage around the unbroken strand thus removing DNA supercoils. Finally, in the religation step, the DNA 5'-OH attacks the covalent intermediate to expel the active-site tyrosine and restore the DNA phosphodiester backbone (By similarity). Regulates the alternative splicing of tissue factor (F3) pre-mRNA in endothelial cells. {ECO:0000250, ECO:0000269PubMed:14594810, ECO:0000269PubMed:16033260, ECO:0000269PubMed:19168442, ECO:0000269PubMed:2833744}.

Subcellular Localization

Nucleus, nucleolus {ECO:0000269PubMed:12149243}. Nucleus, nucleoplasm {ECO:0000269PubMed:12149243}. Note=Diffuse nuclear localization with some enrichment in nucleoli. On CPT treatment, cleared from nucleoli into nucleoplasm. Sumolyated forms found in both nucleoplasm and nucleoli.

Disease Associations

Note=A chromosomal aberration involving TOP1 is found in a form of therapy-related myelodysplastic syndrome. Translocation t(11;20)(p15;q11) with NUP98.

Tissue Specificity

Endothelial cells. {ECO:0000269PubMed:19168442}.

Comments

Interactions

Number of Interactions

This gene and/or its encoded proteins are associated with 166 experimentally validated interaction(s) in this database.
They are also associated with 3 interaction(s) predicted by orthology.

Experimentally validated
Total	166 [view]
Protein-Protein	160 [view]
Protein-DNA	4 [view]
Protein-RNA	1 [view]
DNA-DNA	0
RNA-RNA	1 [view]
DNA-RNA	0

Predicted by orthology
Total	3 [view]

Gene Ontology

Molecular Function

Accession	GO Term
GO:0003677	DNA binding
GO:0003682	chromatin binding
GO:0003917	DNA topoisomerase type I activity
GO:0003918	DNA topoisomerase (ATP-hydrolyzing) activity
GO:0005515	protein binding
GO:0044822	poly(A) RNA binding

Biological Process

GO:0006200	ATP catabolic process
GO:0006260	DNA replication
GO:0006265	DNA topological change
GO:0006338	chromatin remodeling
GO:0007059	chromosome segregation
GO:0012501	programmed cell death
GO:0016032	viral process
GO:0016310	phosphorylation
GO:0040016	embryonic cleavage
GO:0042493	response to drug

Cellular Component

GO:0000228	nuclear chromosome
GO:0000932	cytoplasmic mRNA processing body
GO:0005634	nucleus
GO:0005654	nucleoplasm
GO:0005694	chromosome
GO:0005730	nucleolus
GO:0005737	cytoplasm
GO:0031298	replication fork protection complex
GO:0043204	perikaryon

Protein Structure and Domains

PDB ID

InterPro

IPR001631 DNA topoisomerase I
IPR008336 DNA topoisomerase I, DNA binding, eukaryotic-type
IPR011010 DNA breaking-rejoining enzyme, catalytic core
IPR013499 DNA topoisomerase I, eukaryotic-type
IPR013500 DNA topoisomerase I, catalytic core, eukaryotic-type

PFAM

PF02919
PF01028

PRINTS

PR00416

PIRSF

SMART

SM00435

TIGRFAMs

Post-translational Modifications

Modification

Cross-References

SwissProt