摘要

Glutathione reductase (GLR) null mutants of the yeast Kluyveromyces lams, a model eukaryotic respiratory cell, were created and phenotypically analysed. We found that cells lacking GLR show decreased resistance to oxidative stress and higher levels of reactive oxygen species and catalase activity than the wild-type strain. However. glutathione redox levels (GSH : GSSG ratio) were similar in the Delta Klglr1 mutant and wild-type strains. The thioredoxin thioredoxin reductase system is proposed as an alternative system for maintaining the GSH:GSSG ratio in the Delta Klglr1 mutant. The involvement of GLR in glucose metabolism in K. lactis is suggested by the improved growth on glucose caused by the Delta Klglr1 mutation and by the increased GLR activity in the Delta Klgcr1 strain, KlGer1 being a transcriptional activator of glycolytic genes. We also studied the subcellular location of GLR in K. laths, showing that it is present in mitochondria; however, the Delta Klglr1 mutation does not affect mitochondrial morphology. Genomic DNA integrity and life span are also unaffected by the Delta Klglr1 mutation, at least under the conditions tested in this study.

  • 出版日期2010-7