Physical interaction between heat shock proteins DnaK, DnaJ, and GrpE and the bacterial heat shock transcription factor σ32

Expression of an Atriplex nummularia gene encoding a protein homologous to the bacterial molecular chaperone DnaJ.

“…The 73-kD heat shock protein detected by anti-Sec63 serum was present only in soluble protein fractions (100,000g supernatant), whereas the yeast Sec63 has three potential membrane spanning domains and was shown Time represents the period after inoculation of stationary phase cells into fresh medium (see Casas et al, 1991, for growth data on these cells). and the heat shock transcription factor o 32 occurs independently of DnaK (Gamer et al, 1992).…”

Heat‐shock proteins as molecular chaperones

“…DnaJ, a protein-binding protein in its own right (Langer et al, 1992a), stimulates the ATPase activity of DnaK (Liberek et al, 1991a). In some cases the interaction of DnaJ increases binding of DnaK to its substrate proteins such as denatured rhodanese (Langer et al, 1992a), transcriptional activator u3' (Gamer et al, 1992) and the bacteriophage P1 RepA dimer, converting it to the active monomeric form (Wickner et al, 1991(Wickner et al, , 1992. In the presence of both DnaJ and GrpE the ATPase activity of DnaK can be accelerated up to 50-fold.…”

Mdj1p, a novel chaperone of the DnaJ family, is involved in mitochondrial biogenesis and protein folding

“…DnaJ stimulates the ATPase activity of DnaK, whereas GrpE acts as a nucleotide exchange factor (Liberek et al, 1991). In this manner, these three heat shock proteins participate in a variety of processes, such as bacteriophage I, DNA replication, protein folding, and regulation of heat shock response (Zylicz et al, 1989;Langer et al, 1992;Gamer et al, 1992).…”