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FLASH GENE
Symbol TOP1 contributors: mct - updated : 04/11/2008
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 dog TOP1 (98.2 pc)
    homolog to chimpanzee TOP1 (100 pc)
    homolog to cow TOP1 (98.7 pc)
    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
    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