The impact of dnaKJ overexpression on recombinant protein solubility results from antagonistic effects on the control of protein quality.
We have produced increasing levels of DnaK and its co-chaperone DnaJ along with the model VP1LAC misfolding-prone protein, to explore the role of DnaK on the management of Escherichia coli inclusion bodies. While relative solubility of VP1LAC is progressively enhanced, the heat-shock response is down-regulated as revealed by decreasing levels of GroEL. This is accompanied by an increasing yield of VP1LAC and a non-regular evolution of its insoluble fraction, at moderate levels of DnaK resulting in more abundant inclusion bodies. Also, the impact of chaperone co-expression is much more pronounced in wild type cells than in a DnaK- mutant, probably due to the different background of heat shock proteins in these cells. The involvement of DnaK in the supervision of misfolding proteins is then pictured as a dynamic balance between its immediate holding and folding activities, and the side-effect downregulation of the heat shock response though the limitation of other chaperone and proteases activities.
Petersson
Lisa
L
Departament de Genètica i de Microbiologia, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de, Barcelona, Bellaterra, 08193 Barcelona, Spain.
Carrió
M Mar
MM
Vera
Andrea
A
Villaverde
Antonio
A
D019281:Dimerization; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006360:Heat-Shock Proteins; D018869:Heat-Shock Response / Q000502:physiology; D002479:Inclusion Bodies / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D015202:Protein Engineering / Q000379:methods*; D011994:Recombinant Proteins / Q000737:chemistry* / Q000378:metabolism*; D012995:Solubility
C494635:DnaJ protein, E coli; D029968:Escherichia coli Proteins; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D011994:Recombinant Proteins; C063842:dnaK protein, E coli