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Updated: Sep 26, 2026

Genetic Engineering of Dictyostelium discoideum Cells Based on Selection and Growth on Bacteria
Published on: January 25, 2019
Only one dnaK homolog, dnaK2, is active transcriptionally and is essential in Synechocystis
Viktória Varvasovszki1, Attila Glatz, Natalia Shigapova
1Institute of Biochemistry, Biological Research Center, Hungarian Academy of Sciences, P.O. Box 521, H-6701 Szeged, Hungary.
Abstract:
We examined the expression and the function of the DnaK chaperone family in the photoautotrophic cyanobacterium, Synechocystis PCC 6803. Surprisingly, only one of the three dnaK genes was transcribed either under normal or heat shock conditions. Their predicted cochaperones (four dnaJs and one grpE) proved to be uninducible under our experimental conditions. Attempts to inactivate the active dnaK2 has failed, indicating that the gene is essential. The partial mutant displayed lower inducibility of chaperones (especially GroEL and HSP17) both at mRNA and protein levels upon heat shock. The mutant showed temperature sensitive phenotype, but was able to acquire thermotolerance.
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