Virulence in bacteriophage Mu: a case of trans-dominant proteolysis by the Escherichia coli Clp serine protease.
The importance of proteases in gene regulation is well documented in both prokaryotic and eukaryotic systems. Here we describe the first example of genetic regulation controlled by the Escherichia coli Clp ATP-dependent serine protease. Virulent mutants of bacteriophage Mu, which carry a particular mutation in their repressor gene (vir mutation), successfully infect Mu lysogens and induce the resident Mu prophage. We show that the mutated repressors have an abnormally short half-life due to an increased susceptibility to Clp-dependent degradation. This susceptibility is communicated to the wild type repressor present in the same cell, which provides the Muvir phages with their trans-dominant phenotype. To our knowledge this is the first case where the instability of a mutant protein is shown to trigger the degradation of its wild type parent.
Geuskens
V
V
Unité Transposition Bactérienne, Université Libre de Bruxelles, Belgium.
Mhammedi-Alaoui
A
A
Desmet
L
L
Toussaint
A
A
D049069:ATP-Dependent Proteases; D000595:Amino Acid Sequence; D010583:Bacteriophage mu / Q000472:pathogenicity*; D001483:Base Sequence; D002874:Chromosome Mapping; D004271:DNA, Fungal; D004926:Escherichia coli / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D006360:Heat-Shock Proteins; D006868:Hydrolysis; D008969:Molecular Sequence Data; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D054334:Viral Regulatory and Accessory Proteins; D014774:Virulence / Q000235:genetics
D004271:DNA, Fungal; D006360:Heat-Shock Proteins; D012097:Repressor Proteins; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C016649:phage repressor proteins; D049069:ATP-Dependent Proteases; D012697:Serine Endopeptidases