MnSOD overexpression extends the yeast chronological (G(0)) life span but acts independently of Sir2p histone deacetylase to shorten the replicative life span of dividing cells

• Type: Article in International Scientific Journal
• Date: 2003

Authors

Harris, N (Author) Other; Vitor Costa (Author) ICBAS; MacLean, M (Author) Other; Mollapour, M (Author) Other; Pedro Moradas Ferreira (Author) ICBAS; Piper, PW (Author) Other

Journal

Title: Free Radical Biology and Medicine

Vol. 34

Pages: 1599-1606

ISSN: 0891-5849

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 71 Citations

Scopus - 78 Citations

Other information

Authenticus ID: P-000-G94

DOI: 10.1016/s0891-5849(03)00210-7

Abstract (EN): Studies in Drosophila and Caenorhabditis elegans have shown increased longevity with the increased free radical scavenging that accompanies overexpression of oxidant-scavenging enzymes. This study used yeast, another model for aging research, to probe the effects of overexpressing the major activity protecting against superoxide generated by the mitochondrial respiratory chain. Manganese superoxide dismutase (MnSOD) overexpression increased chronological life span (optimized survival of stationary (G(0)) yeast over time), showing this is a survival ultimately limited by oxidative stress. In contrast, the same overexpression dramatically reduced the replicative life span of dividing cells (the number of daughter buds produced by each newly born mother cell). This reduction in the generational life span by MnSOD overexpression was greater than that generated by loss of the major redox-responsive regulator of the yeast replicative life span, NAD+-dependent Sir2p histone deacetylase. It was also independent of the latter activity. Expression of a mitochondrially targeted green fluorescent protein in the MnSOD overexpressor revealed that the old mother cells of this overexpressor, which had divided for a few generations, were defective in segregation of the mitochondrion from the mother to daughter. Mitochondrial defects are, therefore, the probable reason that MnSOD overexpression shortens replicative life span. (C) 2003 Elsevier Inc.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8