The phasevarion: a genetic system controlling coordinated, random switching of expression of multiple genes

Proc Natl Acad Sci U S A. 2005 Apr 12;102(15):5547-51. doi: 10.1073/pnas.0501169102. Epub 2005 Mar 31.

Abstract

Several host-adapted bacterial pathogens contain methyltransferases associated with type III restriction-modification (R-M) systems that are subject to reversible, high-frequency on/off switching of expression (phase variation). To investigate the role of phase-variable expression of R-M systems, we made a mutant strain lacking the methyltransferase (mod) associated with a type III R-M system of Haemophilus influenzae and analyzed its phenotype. By microarray analysis, we identified a number of genes that were either up- or down-regulated in the mod mutant strain. This system reports the coordinated random switching of a set of genes in a bacterial pathogen and may represent a widely used mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Codon, Initiator / genetics
  • DNA Methylation
  • DNA Modification Methylases / genetics*
  • DNA, Bacterial / genetics
  • DNA, Bacterial / metabolism
  • Gene Expression Profiling
  • Gene Expression Regulation, Bacterial / genetics*
  • Genes, Bacterial / genetics*
  • Haemophilus influenzae / cytology
  • Haemophilus influenzae / enzymology
  • Haemophilus influenzae / genetics*
  • Haemophilus influenzae / immunology
  • Heat-Shock Proteins / genetics
  • Heat-Shock Response
  • Host-Parasite Interactions
  • Macrophage Activation
  • Mutation / genetics
  • Oligonucleotide Array Sequence Analysis
  • Phenotype

Substances

  • Bacterial Proteins
  • Codon, Initiator
  • DNA, Bacterial
  • Heat-Shock Proteins
  • DNA Modification Methylases