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PEO1 (human)

PEO1 Involved in mitochondrial DNA (mtDNA) metabolism. Could function as an adenine nucleotide-dependent DNA helicase. Function inferred to be critical for lifetime maintenance of mtDNA integrity. In vitro, forms in combination with POLG, a processive replication machinery, which can use double-stranded DNA (dsDNA) as template to synthesize single-stranded DNA (ssDNA) molecules. May be a key regulator of mtDNA copy number in mammals. Defects in PEO1 are the cause of progressive external ophthalmoplegia with mitochondrial DNA deletions autosomal dominant type 3 (PEOA3). Progressive external ophthalmoplegia is characterized by progressive weakness of ocular muscles and levator muscle of the upper eyelid. In a minority of cases, it is associated with skeletal myopathy, which predominantly involves axial or proximal muscles and which causes abnormal fatigability and even permanent muscle weakness. Ragged- red fibers and atrophy are found on muscle biopsy. A large proportion of chronic ophthalmoplegias are associated with other symptoms, leading to a multisystemic pattern of this disease. Additional symptoms are variable, and may include cataracts, hearing loss, sensory axonal neuropathy, ataxia, depression, hypogonadism, and parkinsonism. Defects in PEO1 are a cause of sensory ataxic neuropathy dysarthria and ophthalmoparesis (SANDO). SANDO is a clinically heterogeneous systemic disorder with variable features resulting from mitochondrial dysfunction. It shares phenotypic characteristics with autosomal recessive progressive external ophthalmoplegia and mitochondrial neurogastrointestinal encephalopathy syndrome. The clinical triad of symptoms consists of sensory ataxic, neuropathy, dysarthria, and ophthalmoparesis. Defects in PEO1 are the cause of mitochondrial DNA depletion syndrome type 7 (MTDPS7); also known as spinocerebellar ataxia infantile-onset (IOSCA). A severe disease associated with mitochondrial dysfunction. Some patients are affected by progressive atrophy of the cerebellum, brain stem, the spinal cord, and sensory axonal neuropath. Clinical features include hypotonia, athetosis, ataxia, ophthalmoplegia, sensorineural hearing deficit, sensory axonal neuropathy, epileptic encephalopathy and female hypogonadism. Some individuals manifest a hepatocerebral phenotype characterized by liver insufficiency, increased serum and CSF lactate, hypotonia, psychomotor retardation and peripheral neuropathy. 3 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Protein type: Helicase; EC; DNA replication; EC 3.6.1.-; Mitochondrial
Molecular Function: protease binding; 5'-3' DNA helicase activity; single-stranded DNA binding; ATP binding
Biological Process: DNA unwinding during replication; cell death; mitochondrial DNA replication; protein homooligomerization; transcription from mitochondrial promoter
Reference #:  Q96RR1 (UniProtKB)
Alt. Names/Synonyms: ataxin 8; ATXN8; C10orf2; chromosome 10 open reading frame 2; FLJ21832; IOSCA; PEO; PEO1; PEOA3; Progressive external ophthalmoplegia 1 protein; SANDO; SCA8; T7 gp4-like protein with intramitochondrial nucleoid localization; T7-like mitochondrial DNA helicase; Twinkle protein, mitochondrial; TWINL
Gene Symbols: C10orf2
Molecular weight: 77,154 Da
Basal Isoelectric point: 9.13  Predict pI for various phosphorylation states
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Protein Structure Not Found.

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Modification Sites and Domains  

Modification Sites in Parent Protein, Orthologs, and Isoforms  

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SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.


MS: The number of records in which this modification site was assigned using ONLY proteomic discovery-mode mass spectrometry.



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