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FLASH GENE
Symbol TOP1 contributors: mct - updated : 24-02-2015
HGNC name topoisomerase (DNA) I
HGNC id 11986
Location 20q12-q13.1      Physical location : 39.657.461 - 39.753.124
Synonym symbol(s) TOPI
EC.number 5.99.1.2
DNA
TYPE functioning gene
STRUCTURE 95.67 kb     21 Exon(s)
10 Kb 5' upstream gene genomic sequence study
MAPPING cloned Y linked N status confirmed
RNA
TRANSCRIPTS type messenger
identificationnb exonstypebpproduct
ProteinkDaAAspecific expressionYearPubmed
21 - 3734 90.6 765 - -
EXPRESSION
Type ubiquitous
   expressed in (based on citations)
organ(s)
SystemOrgan level 1Organ level 2Organ level 3Organ level 4LevelPubmedSpeciesStageRna symbol
Digestiveesophagus   highly
 mouthtongue  highly
Lymphoid/Immunelymph node   moderately
Nervousbrainhindbraincerebellum highly
Reproductivefemale systemplacenta  moderately
Respiratoryrespiratory tracttrachea  highly
Urinarykidney   moderately
cells
SystemCellPubmedSpeciesStageRna symbol
NervousPurkinje cell
cell lineage
cell lines
fluid/secretion
at STAGE
PROTEIN
PHYSICAL PROPERTIES
STRUCTURE
motifs/domains
  • an unstructured N-terminal domain of 200 amino acids
  • a structured functional domain of 565 amino acids that binds and relaxes supercoiled DNA
  • conjugated Other
    mono polymer monomer
    HOMOLOGY
    interspecies homolog to rattus Top1 (97.3 pc)
    homolog to murine Top1 (97.3 pc)
    Homologene
    FAMILY
  • eukaryotic type I topoisomerase family
  • CATEGORY enzyme , protooncogene
    SUBCELLULAR LOCALIZATION     intracellular
    intracellular,cytoplasm
    intracellular,nucleus,nucleoplasm
    intracellular,nucleus,nucleolus
    text
  • perikaryon
  • very high levels of topoisomerase 1 (TOP1) in the nucleus, and specifically the nucleolus, of human Purkinje neurons (Gorodetsky 2007)
  • basic FUNCTION
  • DNA topoisomerase I, relaxing negatively supercoiled DNA and releasing torsion stress created by DNA transcription
  • catalyzing the ATP independent breakage and rejoining of single strand of DNA
  • involved in DNA repair
  • aborting in cells treated by antitumor drugs with the production of topoisomerase-DNA damage, finally distroyed by ubiquitin after conjugation with SUMO1 (UBL1)
  • CELLULAR PROCESS cell life, cell death/apoptosis
    nucleotide, replication
    nucleotide, recombination
    PHYSIOLOGICAL PROCESS
    PATHWAY
    metabolism
    signaling
    a component
    INTERACTION
    DNA binding to single stand
    RNA
    small molecule
    protein
  • TOP2A, TOP1 are involved in initiating aphidicolin-induced common fragile site breakage at RET, and may engage the recognition of DNA secondary structures formed during perturbed DNA replication
  • cell & other
    REGULATION
    activated by phosphorylation (stimulates its DNA relaxation activity)
    inhibited by camptothecin (specifically)
    Other sumoylation playing a role in partitioning TOP1 between nucleoli and nucleoplasm (Lys-117 being the main site of sumoylation)
    ASSOCIATED DISORDERS
    corresponding disease(s)
    Other morbid association(s)
    TypeGene ModificationChromosome rearrangementProtein expressionProtein Function
    tumoral fusion      
    fused with NUP98 in t(11;20)(p15;q11) in therapy related myelodysplastic syndrome
    Susceptibility
    Variant & Polymorphism
    Candidate gene
    Marker
    Therapy target
    ANIMAL & CELL MODELS