TY - JOUR
T1 - Multiple copies of the pyruvate kinase gene affect yeast cell growth
AU - Moore, P. A.
AU - Bettany, A. J.E.
AU - Brown, A. J.P.
PY - 1990/1/1
Y1 - 1990/1/1
N2 - The Saccharomyces cerevisiae pyruvate kinase gene (PYK1) was transformed into yeast using the multicopy vector pJDB207. Growth rates and PYK1 gene expression levels varied considerably amongst the transformants. Yeast transformants expressing the PYK1 gene at high levels formed small colonies compared with those expressing the gene at relatively low levels. Slow-growing transformants 'reverted' at high frequency to more rapid growth, and this correlated with decreases in PYK1 gene copy number and PYK1 mRNA abundance. This apparent selection against PYK1 over-expression was disrupted by the introduction of a stop codon at the 5'-end of the PYK1 coding region, thus confirming that the growth effects were mediated by the PYK1 gene. However, massive overproduction of pyruvate kinase in yeast, using multiple copies of a PGK:PYK gene fusion, had no significant effect upon cell growth. This suggests that the deleterious effect upon the host yeast cell is mediated by abnormally high levels of the wild-type gene or PYK1 mRNA, rather than by increased pyruvate kinase levels.
AB - The Saccharomyces cerevisiae pyruvate kinase gene (PYK1) was transformed into yeast using the multicopy vector pJDB207. Growth rates and PYK1 gene expression levels varied considerably amongst the transformants. Yeast transformants expressing the PYK1 gene at high levels formed small colonies compared with those expressing the gene at relatively low levels. Slow-growing transformants 'reverted' at high frequency to more rapid growth, and this correlated with decreases in PYK1 gene copy number and PYK1 mRNA abundance. This apparent selection against PYK1 over-expression was disrupted by the introduction of a stop codon at the 5'-end of the PYK1 coding region, thus confirming that the growth effects were mediated by the PYK1 gene. However, massive overproduction of pyruvate kinase in yeast, using multiple copies of a PGK:PYK gene fusion, had no significant effect upon cell growth. This suggests that the deleterious effect upon the host yeast cell is mediated by abnormally high levels of the wild-type gene or PYK1 mRNA, rather than by increased pyruvate kinase levels.
UR - http://www.scopus.com/inward/record.url?scp=0025651646&partnerID=8YFLogxK
U2 - 10.1099/00221287-136-12-2359
DO - 10.1099/00221287-136-12-2359
M3 - Article
C2 - 2079627
AN - SCOPUS:0025651646
SN - 0022-1287
VL - 136
SP - 2359
EP - 2366
JO - Journal of General Microbiology
JF - Journal of General Microbiology
IS - 12
ER -