The grpE gene of Escherichia coli is essential for bacteriophage λ DNA replication and is also necessary for host RNA and DNA synthesis at high temperature. A grpE mutant of E. coli was found to be substantially more resistant to 50°C heat treatment than the wild-type. Upon receiving a 42°C heat shock for 15 min, both the wild-type and the grpE mutant became more resistant to heat (i.e. they became thermotolerant). A grpE+ revertant behaved similarly to the wild-type in that it was more sensitive to heat than grpE cells. In addition, grpE cells had the same H2O2 and UV sensitivity as the wild-type. This implies that the conditions for which a grpE mutation is beneficial are unique to heat exposure and are not caused by H2O2 or UV exposure. Furthermore, synthesis of heat-shock proteins occurred sooner in the grpE mutant than in the wild-type, indicating that the grpE gene of E. coli may influence the regulation of the heat-shock response.
AngD.,
ChandrasekharG. N.,
ZyliczM.,
GeorgopoulosC.1986; Escherichia coli grpE gene codes for heat shock protein B25.3, essential for both λ DNA replication at all temperatures and host growth at high temperature. Journal of Bacteriology 167:25–29
FurthM. E.,
WicknerS. H.1983; Lambda DNA replication. In LambdaII pp. 145–173HendrixR. W.,
RobertsJ. W.,
StahlF. W.,
WeisbergR. A.
Edited by Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
KruegerJ. H.,
WalkerG. C.1984; groEL and dnaK genes of Escherichia coli are induced by UV irradiation and nalidixic acid in an htpR+-dependent fashion. Proceedings of the National Academy of Sciences of the United States of America 81:1499–1503
LiberekK.,
GeorgopoulosC.,
ZyliczM.1988; Role of Escherichia coli DnaK and DnaJ heat shock proteins in the initiation of bacteriophage λ DNA replication. Proceedings of the National Academy of Sciences of the United States of America 85:6632–6636
NeidhardtF. C.,
VanbogelenR. A.1981; Positive regulatory gene for temperature-controlled proteins in Escherichia coli
. Biochemical and Biophysical Research Communications 100:894–900
VanbogelenR. A.,
ActonM. A.,
NeidhardtR. C.1987a; Induction of the heat shock regulon does not produce thermotolerance in Escherichia coli
. Genes and Development 1:525–531
VanbogelenR. A.,
KelleyP. M.,
NeidhardtR. C.1987b; Differential induction of heat shock, SOS, and oxidation stress regulons and accumulation of nucleotides in Escherichia coli
. Journal of Bacteriology 169:26–32
YamamoriT.,
YuraT.1982; Genetic control of heat-shock protein synthesis and its bearing on growth and thermal resistance in Escherichia coli K-12. Proceedings of the National Academy of Sciences of the United States of America 79:860–864