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FLASH GENE
Symbol POLG contributors: mct/npt - updated : 01- 02-202
HGNC name polymerase (DNA directed), gamma
HGNC id 9179
Corresponding disease
AMS1 ataxia-myopathy syndrome 1
MNGIE2 mitochondrial neurogastrointestinal encephalopathy
OLEN occipital lobe epilepsy with nystagmus
PEO1 progressive external ophthalmoplegia 1
PNDC neuronal degeneration of childhood with liver disease, progressive
SANDO sensory ataxic neuropathy, dysarthria, and ophthalmoparesis
Location 15q26.1      Physical location : 89.859.536 - 89.878.026
Synonym name
  • DNA polymerase subunit gamma-1
  • mitochondrial DNA polymerase catalytic subunit
  • PolG, catalytic subunit
    • Synonym symbol(s) FLJ27114, MDP1, PEO, POLG1, POLGA, SANDO, SCAE, PolG-alpha, MIRAS, MTDPS4A, MTDPS4B
    EC.number 2.7.7.7
    DNA
    TYPE functioning gene
    STRUCTURE 18.50 kb     23 Exon(s)
    10 Kb 5' upstream gene genomic sequence study
    text structure (CAG)10 repeat in the first exon
    MAPPING cloned Y linked N status confirmed
    RNA
    TRANSCRIPTS type messenger
    text variants encode the same protein
    identificationnb exonstypebpproduct
    ProteinkDaAAspecific expressionYearPubmed
    23 - 4450 139.4 1239 - 2021 34189666
    23 - 4462 139.4 1239 - 2021 34189666
    EXPRESSION
    Type widely
       expressed in (based on citations)
    organ(s)
    SystemOrgan level 1Organ level 2Organ level 3Organ level 4LevelPubmedSpeciesStageRna symbol
    blood / hematopoieticspleen   highly
    Cardiovascularheart   highly
    Digestiveliver    
    Endocrinepancreas    
    Nervousbrain    
     spinal cord   highly
    Respiratorylung    
    Urinarykidney    
    tissue
    SystemTissueTissue level 1Tissue level 2LevelPubmedSpeciesStageRna symbol
    Epithelialsecretoryglandularendocrine 
    Lymphoid    
    Muscularstriatumskeletal  
    Nervouscentral   
    cell lineage
    cell lines
    fluid/secretion
    at STAGE
    PROTEIN
    PHYSICAL PROPERTIES
    STRUCTURE
    motifs/domains
  • an N terminal polyglutamine region
  • a polymerase motif B
  • a exonuclease motif
  • a spacer-region
    • mono polymer heteromer , dimer , trimer
    HOMOLOGY
    interspecies homolog to murine Polg
    homolog to Drosophila tam
    homolog to C.elegans Y57A10A.15
    Homologene
    FAMILY
  • DNA polymerase type A family
    • CATEGORY enzyme
    SUBCELLULAR LOCALIZATION     intracellular
    intracellular,cytoplasm,organelle,mitochondria,matrix
    intracellular,nucleus
    basic FUNCTION
  • involved in the replication of mitochondrial DNA
  • playing an essential role for the organogenesis during embryonic development
  • encodes the mitochondrial DNA polymerase that is responsible for replication of the mitochondrial genome
  • is responsible for the replication and repair of mitochondrial DNA (mtDNA)
    • CELLULAR PROCESS nucleotide, replication
    PHYSIOLOGICAL PROCESS
    text mitochondrial DNA replication
    PATHWAY
    metabolism
    signaling
    a component
  • subunit of DNA poymerase gamma
  • heterotrimer composed of a 140kDa catalytic subunit (POLG alpha)and a 55 kDa accessory subunit (POLG beta)
    • INTERACTION
    DNA binding
    RNA
    small molecule metal binding,
  • Mg2+
    • protein
  • interacting with LIG3 (interaction of DNA ligase III and DNA polymerase gamma is required for proper maintenance of the mitochondrial genome)
  • co-association of NEIL2 and PNKP with POLG on the mitochondrial genome
  • MGME1 interacts with the mitochondrial replicase POLG, suggesting that it is a constituent of the mitochondrial replisome, to which it provides an additional exonuclease activity
  • among the direct targets of POLR3G, POLG is potentially important in sustaining stem cell status in a POLR3G-dependent manner
    • cell & other
    REGULATION
    ASSOCIATED DISORDERS
    corresponding disease(s) PEO1 , AMS1 , PNDC , SANDO , MNGIE2 , OLEN
    related resource MITOP database
    Other morbid association(s)
    TypeGene ModificationChromosome rearrangementProtein expressionProtein Function
    constitutional somatic mutation      
    in substantia nigra of Parkinson disease, with respiratory deficiency
    constitutional     --low  
    co- deficient expression of POLG and SSBP1 genes could contribute to the development of mtDNA deletion
    Susceptibility
  • to male infertility
  • to deletion of mitochondrial DNA
  • to testicular germ-cell can
    • Variant & Polymorphism SNP , repeat , other
  • common A467T associated to reduced polymerase activity and loss of accessory subunit interaction are responsible for the depletion and deletion of mitochondrial DNA
  • association of the polymorphism of the CAG repeat with testicular germ-cell cancer (Blomberg 2008)
    • Candidate gene
    Marker
    Therapy target
    ANIMAL & CELL MODELS
  • mice expressing proofreading-deficient version of the mitochondrial POLG accumulate mtDNA mutations and display features of accelerated aging
  • in mice a mutation in the catalytic subunit of polymerase gamma (POLG) was associated with haematopoietic dysfunction including anaemia