Connection between gene dosage and protein stability revealed by a high-yield production of recombinant proteins in an E. coli LexA1(Ind-) background.
Bacterial production of a plasmid-encoded bacteriophage P22 tailspike protein shows different yield and impact on cell viability in RecA+ LexA+, RecA- LexA+ and RecA+ LexA1(Ind-) backgrounds. In a LexA1(Ind-) context, we have observed lesser toxicity and higher productivity than in the wild-type strain, in which the bacterial growth was inhibited after induction of recombinant gene expression. Also, a negative effect of the incubation temperature on the growth of producing cells was also detected. By exploring the molecular basis of these inhibitory events, we found a connection between the dosage of the recombinant gene and the proteolytic stability of the encoded protein. Under both genetic and environmental conditions favoring higher plasmid copy number and consequently increasing the synthesis rate of the recombinant protein, enhanced protein degradation was observed in parallel with an important growth inhibition. Altogether, the obtained data suggest the existence of a critical concentration of recombinant protein over which cell proteolysis is stimulated at rates not compatible with optimal physiological conditions for bacterial growth.
Medina
Manel G
MG
Institut de Biologia Fonamental and Departament de Genètica and Microbiologia, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain.
Carbonell
Xavier
X
Villaverde
Antonio
A
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004260:DNA Repair; D004269:DNA, Bacterial / Q000235:genetics; D004274:DNA, Recombinant; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D015870:Gene Expression; D015964:Gene Expression Regulation, Bacterial; D006026:Glycoside Hydrolases / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D008957:Models, Genetic; D015233:Models, Statistical; D010957:Plasmids / Q000235:genetics; D011994:Recombinant Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics*; D011995:Recombination, Genetic; D012680:Sensitivity and Specificity; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D013997:Time Factors; D017376:Viral Tail Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D000099160:LexA Repressor Protein
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004274:DNA, Recombinant; D006026:Glycoside Hydrolases; D011994:Recombinant Proteins; D012697:Serine Endopeptidases; D017376:Viral Tail Proteins; D000099160:LexA Repressor Protein; C083268:tailspike protein, bacteriophage