Year: 2006
Type: article
Abstract: Thioredoxin was initially identified by its ability to serve as an electron donor for ribonucleotide reductase in vitro. Whether it serves a similar function in vivo is unclear. In Saccharomyces cerevisiae, it was previously shown that Deltatrx1 Deltatrx2 mutants lacking the two genes for cytosolic thioredoxin have a slower growth rate because of a longer S phase, but the basis for S phase elongation was not identified. The hypothesis that S phase protraction was due to inefficient dNTP synthesis was investigated by measuring dNTP levels in asynchronous and synchronized wild-type and Deltatrx1 Deltatrx2 yeast. In contrast to wild-type cells, Deltatrx1 Deltatrx2 cells were unable to accumulate or maintain high levels of dNTPs when alpha-factor- or cdc15-arrested cells were allowed to reenter the cell cycle. At 80 min after release, when the fraction of cells in S phase was maximal, the dNTP pools in Deltatrx1 Deltatrx2 cells were 60% that of wild-type cells. The data suggest that, in the absence of thioredoxin, cells cannot support the high rate of dNTP synthesis required for efficient DNA synthesis during S phase. The results constitute in vivo evidence for thioredoxin being a physiologically relevant electron donor for ribonucleotide reductase during DNA precursor synthesis.
Source: Journal of Biological Chemistry
Authors: Ahmet Koc, Christopher K. Mathews, Linda J. Wheeler, Michael K. Gross, Gary F. Merrill
Institution: Oregon State University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
Awards: Thioredoxin Control of Transcription during the Cell Cycle, G132990788, G1497661912, G2010940753, Reshaping Civil Society: Islam, Democracy and Diversity in Istanbul, Reducing Susceptibility to Environmental Stress Throughout the Life Span, DEPENDENCE OF P53 ON THIOL MAINTENANCE PROTEINS, G9000092324
OpenAlex ID: W2088272956