TY - JOUR
T1 - Protease-deficient DegP suppresses lethal effects of a mutant OmpC protein by its capture
AU - CastilloKeller, Maria
AU - Misra, Rajeev
PY - 2003/1
Y1 - 2003/1
N2 - The expression of assembly-defective outer membrane proteins can confer lethality if they are not degraded by envelope proteases. We report here that the expression of a mutant OmpC protein, OmpC2cys which forms disulfide bonds in the periplasm due to the presence of two non-native cysteine residues, is lethal in cells lacking the major periplasmic protease, DegP. This lethality is not observed in dsbA strains that have diminished ability to form periplasmic disulfide bonds. Our data show that this OmpC2Cys mediated lethality in a degP:: Kmr dsbA+ background can be reversed by a DegP variant, DegPS210A, that is devoid of its proteolytic activity but retains its reported chaperone activity. However, DegPS210A does not reverse the lethal effect of OmpC2Cys, by correcting its assembly but rather by capturing misfolded mutant OmpC polypeptides and thus removing them from the assembly pathway. Displacement of OmpC2Cys by DegPS210A also alleviates the negative effect that the mutant OmpC protein has on wild-type OmpF.
AB - The expression of assembly-defective outer membrane proteins can confer lethality if they are not degraded by envelope proteases. We report here that the expression of a mutant OmpC protein, OmpC2cys which forms disulfide bonds in the periplasm due to the presence of two non-native cysteine residues, is lethal in cells lacking the major periplasmic protease, DegP. This lethality is not observed in dsbA strains that have diminished ability to form periplasmic disulfide bonds. Our data show that this OmpC2Cys mediated lethality in a degP:: Kmr dsbA+ background can be reversed by a DegP variant, DegPS210A, that is devoid of its proteolytic activity but retains its reported chaperone activity. However, DegPS210A does not reverse the lethal effect of OmpC2Cys, by correcting its assembly but rather by capturing misfolded mutant OmpC polypeptides and thus removing them from the assembly pathway. Displacement of OmpC2Cys by DegPS210A also alleviates the negative effect that the mutant OmpC protein has on wild-type OmpF.
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U2 - 10.1128/JB.185.1.148-154.2003
DO - 10.1128/JB.185.1.148-154.2003
M3 - Article
C2 - 12486051
AN - SCOPUS:0037214416
SN - 0021-9193
VL - 185
SP - 148
EP - 154
JO - Journal of bacteriology
JF - Journal of bacteriology
IS - 1
ER -