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FLASH GENE
Symbol TOP3A contributors: mct - updated : 11-09-2018
HGNC name topoisomerase (DNA) III alpha
HGNC id 11992
Corresponding disease
BLMLS Bloom syndrome-like
Location 17p11.2      Physical location : 18.177.234 - 18.218.321
Synonym name
  • topo III-alpha
  • DNA topoisomerase III alpha
    • Synonym symbol(s) TOP3, ZGRF7, MGRISCE2, PEOB5, TOP3
    EC.number 5.99.1.2
    DNA
    TYPE functioning gene
    STRUCTURE 45.13 kb     19 Exon(s)
    10 Kb 5' upstream gene genomic sequence study
    MAPPING cloned Y linked N status confirmed
    Map see SMCR (phenotype)
    regionally located within the Smith-Magenis critical region
    RNA
    TRANSCRIPTS type messenger
    identificationnb exonstypebpproduct
    ProteinkDaAAspecific expressionYearPubmed
    19 - 4116 - 1001 - 2014 24509834
    18 - 6634 - 906 - 2014 24509834
    EXPRESSION
    Type widely
       expressed in (based on citations)
    organ(s)
    SystemOrgan level 1Organ level 2Organ level 3Organ level 4LevelPubmedSpeciesStageRna symbol
    Digestivemouthtongue  highly
    Lymphoid/Immunethymus   highly
     tonsils   highly
    Reproductivefemale systemuteruscervix highly
    tissue
    SystemTissueTissue level 1Tissue level 2LevelPubmedSpeciesStageRna symbol
    Muscularstriatumskeletal  
    cell lineage
    cell lines
    fluid/secretion
    at STAGE
    physiological period pregnancy
    PROTEIN
    PHYSICAL PROPERTIES
    STRUCTURE
    motifs/domains
    HOMOLOGY
    Homologene
    FAMILY
  • prokaryotic type I/III topoisomerase family
    • CATEGORY enzyme
    SUBCELLULAR LOCALIZATION     intracellular
    intracellular,cytoplasm,organelle,mitochondria
    intracellular,nucleus,nucleoplasm,nuclear bodies,PML
    intracellular,nucleus,chromatin/chromosome
    text
  • three different topoisomerases have been identified in mitochondria: TOP1MT, TOP3A and a truncated form of TOP2B
    • basic FUNCTION
  • putatively involved in suppression of mitotic recombination between repetitive sequences
  • catalyzing the transient breaking and rejoining of a single strand of DNA which allows the strands to pass through one another, thus reducing the number of supercoils and altering the topology of DNA
  • important telomere-associated factor, essential for telomere maintenance and chromosome stability
  • is a type IA DNA topoisomerase that functions with BLM and RMI1 to resolve DNA replication and recombination intermediates
  • is involved in DNA repair surveillance and cell-cycle checkpoints possibly through formatting complex with tumor suppressors
  • mitochondrial TOP3A ablation results in mitochondrial genome instability and its dysfunction, thereby accelerating the aging process
  • is an essential component of the mtDNA replication machinery and as the first component of the mtDNA separation machinery
    • CELLULAR PROCESS
    PHYSIOLOGICAL PROCESS
    PATHWAY
    metabolism
    signaling
    a component
  • colocalizing and complexing with BLM
  • combines with the BLM helicase and RMI1 to form an evolutionarily conserved complex, termed the BTB complex
  • BLM forms the BTRR complex with topoisomerase III alpha (TOP3A) and RecQ-mediated genome instability proteins 1 and 2 (RMI1 and RMI2)
    • INTERACTION
    DNA binding
    RNA
    small molecule
    protein
  • binding and interacting with TOP3B
  • ability of RMI1 to interact with BLM and TOP3A is crucial for RMI1 to respond to replication fork stress
  • TDP2 having preferential action at abortive TOP2A and possibly TOP3A cleavage complexes
  • TOP3A binds to the TP53 and CDKN1A promoters and positively regulates their expression, contributing to the TP53-mediated tumor suppression
  • multifaceted role of the TOP3A-RMI1-RMI2 ensemble and of DNA2 in the DNA resection reaction
    • cell & other
    REGULATION
    ASSOCIATED DISORDERS
    corresponding disease(s) BLMLS
    Other morbid association(s)
    TypeGene ModificationChromosome rearrangementProtein expressionProtein Function
    tumoral fusion      
    fused to KMT12A in an adult patient with acute myeloid leukaemia
    Susceptibility
    Variant & Polymorphism
    Candidate gene
  • TOP3A could be a candidate gene involved in human primary immunodeficiency syndrome
    • Marker
    Therapy target )
    SystemTypeDisorderPubmed
    tumor  
    potential role in dissociating telomeric structures in telomerase-deficient cells, providing therapeutic implications in human tumors
    ANIMAL & CELL MODELS