Dynamin-like 120 kDa protein

Last updated

OPA1
Identifiers
Aliases OPA1 , MGM1, NPG, NTG, largeG, Optic atrophy 1, BERHS, MTDPS14, mitochondrial dynamin like GTPase, OPA1 mitochondrial dynamin like GTPase
External IDs OMIM: 605290; MGI: 1921393; HomoloGene: 14618; GeneCards: OPA1; OMA:OPA1 - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_001199177
NM_133752

RefSeq (protein)
Location (UCSC) Chr 3: 193.59 – 193.7 Mb Chr 16: 29.4 – 29.47 Mb
PubMed search [3] [4]
Wikidata
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Dynamin-like 120 kDa protein, mitochondrial is a protein that in humans is encoded by the OPA1 gene. [5] [6] This protein regulates mitochondrial fusion and cristae structure in the inner mitochondrial membrane (IMM) and contributes to ATP synthesis and apoptosis, [7] [8] [9] and small, round mitochondria. [10] Mutations in this gene have been implicated in dominant optic atrophy (DOA), leading to loss in vision, hearing, muscle contraction, and related dysfunctions. [6] [7] [11]

Structure

Eight transcript variants encoding different isoforms, resulting from alternative splicing of exon 4 and two novel exons named 4b and 5b, have been reported for this gene. [6] They fall under two types of isoforms: long isoforms (L-OPA1), which attach to the IMM, and short isoforms (S-OPA1), which localize to the intermembrane space (IMS) near the outer mitochondrial membrane (OMM). [12] S-OPA1 is formed by proteolysis of L-OPA1 at the cleavage sites S1 and S2, removing the transmembrane domain. [9]

The OPA1 transcript may be alternatively spliced to incorporate a poison exon between exons 5 and 6 or between exons 5b and 6. [13]

Function

This gene product is a nuclear-encoded mitochondrial protein with similarity to dynamin-related GTPases. It is a component of the mitochondrial network. [6] The OPA1 protein localizes to the inner mitochondrial membrane, where it regulates mitochondrial fusion and cristae structure. [7] OPA1 mediates mitochondrial fusion in cooperation with mitofusins 1 and 2 and participates in cristae remodeling by the oligomerization of two L-OPA1 and one S-OPA1, which then interact with other protein complexes to alter cristae structure. [8] [14] Its cristae regulating function also contributes to its role in oxidative phosphorylation and apoptosis, as it is required to maintain mitochondrial activity during low-energy substrate availability. [7] [8] [9] Moreover, stabilization of mitochondrial cristae by OPA1 protects against mitochondrial dysfunction, cytochrome c release, and reactive oxygen species production, thus preventing cell death. [15] Mitochondrial SLC25A transporters can detect these low levels and stimulate OPA1 oligomerization, leading to tightening of the cristae, enhanced assembly of ATP synthase, and increased ATP production. [8] Stress from an apoptotic response can interfere with OPA1 oligomerization and prevent mitochondrial fusion. [9]

Clinical significance

Mutations in this gene have been associated with optic atrophy type 1, which is a dominantly inherited optic neuropathy resulting in progressive loss of visual acuity, leading in many cases to legal blindness. [6] Dominant optic atrophy (DOA) in particular has been traced to mutations in the GTPase domain of OPA1, leading to sensorineural hearing loss, ataxia, sensorimotor neuropathy, progressive external ophthalmoplegia, and mitochondrial myopathy. [7] [11] As the mutations can lead to degeneration of auditory nerve fibres, cochlear implants provide a therapeutic means to improve hearing thresholds and speech perception in patients with OPA1-derived hearing loss. [7]

Mitochondrial fusion involving OPA1 and MFN2 may be associated with Parkinson's disease. [11]

Stoke Therapeutics is evaluating the splice-switching antisense oligonucleotide STK-002 as a potential treatment for DOA. STK-002 reduces poison exon inclusion in the OPA1 transcript, leading to increased OPA1 protein levels. [13]

Interactions

OPA1 has been shown to interact with:

See also

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000198836 Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000038084 Ensembl, May 2017
  3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. Votruba M, Moore AT, Bhattacharya SS (Jan 1998). "Demonstration of a founder effect and fine mapping of dominant optic atrophy locus on 3q28-qter by linkage disequilibrium method: a study of 38 British Isles pedigrees". Human Genetics. 102 (1): 79–86. doi:10.1007/s004390050657. PMID   9490303. S2CID   26060748.
  6. 1 2 3 4 5 "Entrez Gene: OPA1 optic atrophy 1 (autosomal dominant)".
  7. 1 2 3 4 5 6 Santarelli R, Rossi R, Scimemi P, Cama E, Valentino ML, La Morgia C, et al. (Mar 2015). "OPA1-related auditory neuropathy: site of lesion and outcome of cochlear implantation". Brain : A Journal of Neurology. 138 (Pt 3): 563–576. doi:10.1093/brain/awu378. PMC   4339771 . PMID   25564500.
  8. 1 2 3 4 5 6 7 8 9 10 11 Patten DA, Wong J, Khacho M, Soubannier V, Mailloux RJ, Pilon-Larose K, et al. (Nov 2014). "OPA1-dependent cristae modulation is essential for cellular adaptation to metabolic demand". The EMBO Journal. 33 (22): 2676–2691. doi:10.15252/embj.201488349. PMC   4282575 . PMID   25298396.
  9. 1 2 3 4 Anand R, Wai T, Baker MJ, Kladt N, Schauss AC, Rugarli E, et al. (Mar 2014). "The i-AAA protease YME1L and OMA1 cleave OPA1 to balance mitochondrial fusion and fission". The Journal of Cell Biology. 204 (6): 919–929. doi:10.1083/jcb.201308006. PMC   3998800 . PMID   24616225.
  10. Wiemerslage L, Lee D (Mar 2016). "Quantification of mitochondrial morphology in neurites of dopaminergic neurons using multiple parameters". Journal of Neuroscience Methods. 262: 56–65. doi:10.1016/j.jneumeth.2016.01.008. PMC   4775301 . PMID   26777473.
  11. 1 2 3 Carelli V, Musumeci O, Caporali L, Zanna C, La Morgia C, Del Dotto V, et al. (Mar 2015). "Syndromic parkinsonism and dementia associated with OPA1 missense mutations". Annals of Neurology. 78 (1): 21–38. doi:10.1002/ana.24410. PMC   5008165 . PMID   25820230.
  12. Fülöp L, Rajki A, Katona D, Szanda G, Spät A (Dec 2013). "Extramitochondrial OPA1 and adrenocortical function" (PDF). Molecular and Cellular Endocrinology. 381 (1–2): 70–79. doi:10.1016/j.mce.2013.07.021. PMID   23906536. S2CID   5657510.
  13. 1 2 McKenty T, Ali S, Sonntag D, Ravipaty S, Cui Y, Slate D, et al. (2024-10-01). "Antisense Oligonucleotide STK-002 Increases OPA1 in Retina and Improves Mitochondrial Function in Autosomal Dominant Optic Atrophy Cells". Nucleic Acid Therapeutics. 34 (5): 221–233. doi:10.1089/nat.2024.0022. ISSN   2159-3337. PMC   11564677 . PMID   39264859.
  14. Fülöp L, Szanda G, Enyedi B, Várnai P, Spät A (2011). "The effect of OPA1 on mitochondrial Ca²⁺ signaling". PLOS ONE. 6 (9): e25199. doi: 10.1371/journal.pone.0025199 . PMC   3182975 . PMID   21980395.
  15. Varanita T, Soriano ME, Romanello V, Zaglia T, Quintana-Cabrera R, Semenzato M, et al. (Jun 2015). "The OPA1-dependent mitochondrial cristae remodeling pathway controls atrophic, apoptotic, and ischemic tissue damage". Cell Metabolism. 21 (6): 834–844. doi:10.1016/j.cmet.2015.05.007. PMC   4457892 . PMID   26039448.

Further reading