Disease relevance of rpoH

• Induction of heat shock proteins in Escherichia coli is primarily caused by increased cellular levels of the heat shock sigma-factor sigma32 encoded by the rpoH gene [1].
• Primary amino acid sequence comparisons demonstrate that R. sphaeroides RpoH(II) belongs to a phylogenetically distinct group with RpoH orthologs from alpha-proteobacteria that contain two rpoH genes [2].
• Evidence is presented that the activation of the RNA polymerase sigma factor sigma(W) in Bacillus subtilis by regulated intramembrane proteolysis is governed by a novel, membrane-embedded protease [3].

High impact information on rpoH

• To understand the mechanism of heat induction of sigma32 synthesis further, we analyzed expression of rpoH-lacZ gene fusions with altered stability of mRNA structure before and after heat shock [1].
• Like its previously identified paralog, RpoH(I), RpoH(II) is able to complement the temperature-sensitive phenotype of an Escherichia coli sigma(32) (rpoH) mutant [2].
• This study demonstrates that the conserved consensus sequence of the sigma(54) promoter in the regulatory region of the rpoH gene, described previously, is a functional promoter, P6 [4].
• The Escherichia coli heat shock regulatory gene is immediately downstream of a cell division operon: the fam mutation is allelic with rpoH [5].
• We also show that the fam-715 mutation is allelic with rpoH and so the conditional lipoprotein deficiency of the fam mutation must be due to the pleiotropic nature of the heat shock response [5].

Biological context of rpoH

• We determined the relative positions of most of these genes and show that the rpoH gene lies immediately downstream of the last gene (ftsX) of a cell division operon and is transcribed in the same direction [5].

References