Combined effects of the signal sequence and the major chaperone proteins on the export of human cytokines in Escherichia coli.
We have studied the export of two human proteins in the course of their production in Escherichia coli. The coding sequences of the granulocyte-macrophage colony-stimulating factor and of interleukin 13 were fused to those of two synthetic signal sequences to direct the human proteins to the bacterial periplasm. We found that the total amount of protein varies with the signal peptide-cytokine combination, as does the fraction of it that is soluble in a periplasmic extract. The possibility that the major chaperone proteins such as SecB and the GroEL-GroES and DnaK-DnaJ pairs are limiting factors for the export was tested by overexpressing one or the other of these chaperones concomitantly with the heterologous protein. The GroEL-GroES chaperone pair had no effect on protein production. Overproduction of SecB or DnaK plus DnaJ resulted in a marked increase of the quantity of human proteins in the periplasmic fraction, but this increase depends on the signal peptide-heterologous protein-chaperone association involved.
Bergès
H
H
Laboratoire de Microbiologie et Génétique Moléculaire, Centre National de la Recherche Scientifique, Toulouse, France.
Joseph-Liauzun
E
E
Fayet
O
O
D000595:Amino Acid Sequence; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D018793:Interleukin-13 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D018832:Molecular Chaperones / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D021382:Protein Sorting Signals / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000378:metabolism*; D012995:Solubility
D018793:Interleukin-13; D018832:Molecular Chaperones; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D016178:Granulocyte-Macrophage Colony-Stimulating Factor