Go to JCI Insight
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Publication ethics
  • Publication alerts by email
  • Advertising
  • Job board
  • Contact
  • Clinical Research and Public Health
  • Current issue
  • Past issues
  • By specialty
    • COVID-19
    • Cardiology
    • Gastroenterology
    • Immunology
    • Metabolism
    • Nephrology
    • Neuroscience
    • Oncology
    • Pulmonology
    • Vascular biology
    • All ...
  • Videos
    • Conversations with Giants in Medicine
    • Video Abstracts
  • Reviews
    • View all reviews ...
    • Complement Biology and Therapeutics (May 2025)
    • Evolving insights into MASLD and MASH pathogenesis and treatment (Apr 2025)
    • Microbiome in Health and Disease (Feb 2025)
    • Substance Use Disorders (Oct 2024)
    • Clonal Hematopoiesis (Oct 2024)
    • Sex Differences in Medicine (Sep 2024)
    • Vascular Malformations (Apr 2024)
    • View all review series ...
  • Viewpoint
  • Collections
    • In-Press Preview
    • Clinical Research and Public Health
    • Research Letters
    • Letters to the Editor
    • Editorials
    • Commentaries
    • Editor's notes
    • Reviews
    • Viewpoints
    • 100th anniversary
    • Top read articles

  • Current issue
  • Past issues
  • Specialties
  • Reviews
  • Review series
  • Conversations with Giants in Medicine
  • Video Abstracts
  • In-Press Preview
  • Clinical Research and Public Health
  • Research Letters
  • Letters to the Editor
  • Editorials
  • Commentaries
  • Editor's notes
  • Reviews
  • Viewpoints
  • 100th anniversary
  • Top read articles
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Publication ethics
  • Publication alerts by email
  • Advertising
  • Job board
  • Contact

Submit a comment

Defective respiratory capacity and mitochondrial protein synthesis in transformant cybrids harboring the tRNA(Leu(UUR)) mutation associated with maternally inherited myopathy and cardiomyopathy.
C Mariotti, … , S DiDonato, M Zeviani
C Mariotti, … , S DiDonato, M Zeviani
Published March 1, 1994
Citation Information: J Clin Invest. 1994;93(3):1102-1107. https://doi.org/10.1172/JCI117061.
View: Text | PDF
Research Article

Defective respiratory capacity and mitochondrial protein synthesis in transformant cybrids harboring the tRNA(Leu(UUR)) mutation associated with maternally inherited myopathy and cardiomyopathy.

  • Text
  • PDF
Abstract

We studied the physiometabolic effects of a mitochondrial DNA (mtDNA) heteroplasmic point mutation, the A-->G3260 transition associated with maternally inherited myopathy and cardiomyopathy. To eliminate the possible influence of the autochthonous nuclear gene set, we fused myoblast-derived cytoplasts of a patient with a human tumoral cell line deprived of mtDNA (Rho degrees). The presence and amount of the mutant G3260 vs the wild-type A3260 were measured by solid phase minisequencing. We observed a marked reduction of the percentage of mutant mtDNA in the culture system compared with that measured in the donor's muscle biopsy, suggesting the presence of negative selection against the mutation. Furthermore, stable mitotic segregation of the two mtDNA populations was observed in 18 of 19 transformant clones, suggesting the presence of intraorganelle and possibly intracellular homoplasmy in the precursor cells of the donor. Several indexes of mtDNA-related respiratory capacity, including oxygen consumption, complex I- and complex IV-specific activities, and lactate production, were markedly abnormal in the clones containing a high proportion of mutant mtDNA, as compared with those containing homoplasmic wild-type mtDNA, possibly because of impaired mitochondrial protein synthesis. We conclude that (a) the A-->G3260 transition is indeed responsible for the mitochondrial disorder identified in the donor patient, and (b) transformant cybrid system gives direct evidence of the mitochondrial origin of a genetic disorder and should be adopted for the evaluation of the pathogenic potential of the mtDNA mutations.

Authors

C Mariotti, V Tiranti, F Carrara, B Dallapiccola, S DiDonato, M Zeviani

×

Guidelines

The Editorial Board will only consider comments that are deemed relevant and of interest to readers. The Journal will not post data that have not been subjected to peer review; or a comment that is essentially a reiteration of another comment.

  • Comments appear on the Journal’s website and are linked from the original article’s web page.
  • Authors are notified by email if their comments are posted.
  • The Journal reserves the right to edit comments for length and clarity.
  • No appeals will be considered.
  • Comments are not indexed in PubMed.

Specific requirements

  • Maximum length, 400 words
  • Entered as plain text or HTML
  • Author’s name and email address, to be posted with the comment
  • Declaration of all potential conflicts of interest (even if these are not ultimately posted); see the Journal’s conflict-of-interest policy
  • Comments may not include figures
This field is required
This field is required
This field is required
This field is required
This field is required
This field is required

Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)

Sign up for email alerts