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Suppression of polyglutamine‐induced cytotoxicity in Saccharomyces cerevisiae by enhancement of mitochondrial biogenesis
Author(s) -
Ocampo Alejandro,
Zambrano Andrea,
Barrientos Antoni
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.09-148601
Subject(s) - mitochondrial biogenesis , mitochondrion , biology , biogenesis , microbiology and biotechnology , saccharomyces cerevisiae , mutant , protein subunit , mitochondrial toxicity , yeast , biochemistry , gene
Alterations in mitochondrial metabolism have been associated with age‐related neurodegenerative disorders. This is seen in diseases caused by misfolding of proteins with expanded polyglutamine (polyQ) tracts, such as Huntington's disease. Although evidence of mitochondrial impairment has been extensively documented in patients and disease models, the mechanisms involved and their relevance to the initiation of polyQ cytotoxicity and development of clinical manifestations remain controversial. We report that in yeast models of polyQ cytotoxicity, wild‐type and mutant polyQ domains might associate early with the outer mitochondrial membrane. The association of mutant domains with mitochondrial membranes could contribute to induce significant changes in mitochondrial physiology, ultimately compromising the cell's ability to respire. The respiratory defect can be fully prevented by enhancing mitochondrial biogenesis by overexpression of Hap4p, the catalytic subunit of the transcriptional activator Hap2/3/4/5p complex, the master regulator of the expression of many nuclear genes encoding mitochondrial proteins in yeast. Protecting cellular respiratory capacity in this way ameliorates the effect of expanded polyQ on cellular fitness. We conclude that mitochondrial dysfunction is an important contributor to polyQ cytotoxicity. Our results suggest that therapeutic approaches enhancing mitochondrial biogenesis could reduce polyQ toxicity and delay the development of clinical symptoms in patients.—Ocampo, A., Zambrano, A., Barrientos, A. Suppression of polyglutamine‐induced cytotoxicity in Saccharomyces cerevisiae by enhancement of mitochondrial biogenesis. FASEB J. 24, 1431–1441 (2010). www.fasebj.org