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The interplay between SUCLA2, SUCLG2, and mitochondrial DNA depletion
Chaya Miller1, Liya Wang, Elsebet Ostergaard
1Department of Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, POB 1200, 91120 Jerusalem, Israel.
Biochimica Et Biophysica Acta
|February 8, 2011
Summary
Mutations in SUCLA2 cause mitochondrial DNA depletion. The GDP-dependent isoform (SUCLG2) is crucial for mitochondrial DNA maintenance and growth, suggesting its role in disease.
Area of Science:
- Biochemistry
- Cell Biology
- Genetics
Background:
- SUCLA2 mutations cause mitochondrial DNA (mtDNA) depletion syndrome.
- The role of SUCLG2 and mitochondrial nucleoside diphosphate kinase (NDPK) in this process is unclear.
Purpose of the Study:
- Investigate the relationship between SUCLG2, NDPK, and mtDNA maintenance in SUCLA2-deficient cells.
Main Methods:
- Studied fibroblasts from patients with SUCLA2 deficiency.
- Knocked down SUCLG2 expression using shRNA in patient and control fibroblasts.
Main Results:
- SUCLA2-deficient fibroblasts showed normal mtDNA content and NDPK activity.
- SUCLG2 knockdown significantly decreased mtDNA levels, NDPK and cytochrome c oxidase activities, and cell growth.
- These effects were observed in both patient and control cells.
Conclusions:
- SUCLG2 is critical for mtDNA maintenance and cell growth, more so than SUCLA2.
- Mitochondrial NDPK is implicated in the pathomechanism of SUCLA2-related mtDNA depletion syndrome.
- Findings may explain tissue specificity and disease mechanisms in SUCLA2-related disorders.
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