Toggle Main Menu Toggle Search

Open Access padlockePrints

Bacillus subtilis NhaC, an Na+/H+ antiporter, influences expression of the phoPR operon and production of alkaline phosphatases

Lookup NU author(s): Dr Zoltan Pragai, Dr Sierd Bron, Professor Colin Harwood


Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


When Bacillus subtilis is subjected to phosphate starvation, genes of the Pho regulon are either induced or repressed. Among those induced are genes encoding alkaline phosphatases (APases). A set of isogenic mutants, with a β-galactosidase gene transcriptionally fused to the inactivated target gene, was used to identify genes that influence the operation of the Pho regulon. One such gene was nhaC (previously yheL). In the absence of NhaC, growth and APase production were enhanced, while the production of other non-Pho-regulon secretory proteins (proteases and α-amylase) did not change. The influence of NhaC on growth, APase synthesis, and its own expression was dependent on the external Na+ concentration. Other monovalent cations such as Li+ or K+ had no effect. We propose a role for NhaC in the uptake of Na+. nhaC appears to be encoded by a monocistronic operon and, contrary to previous reports, is not in the same transcriptional unit as yheK, the gene immediately upstream. The increase in APase production was dependent on an active PhoR, the sensor kinase of the two-component system primarily responsible for controlling the Pho regulon. Transcriptional fusions showed that the phoPR operon and both phoA (encoding APaseA) and phoB (encoding APaseB) were hyperinduced in the absence of NhaC and repressed when this protein was overproduced. This suggests that NhaC effects APase production via phoPR.

Publication metadata

Author(s): Pragai Z; Harwood CR; Bron S; Eschevins C

Publication type: Article

Publication status: Published

Journal: Journal of Bacteriology

Year: 2001

Volume: 183

Issue: 8

Pages: 2505-2515

Print publication date: 01/01/2001

ISSN (print): 0021-9193

ISSN (electronic): 1098-5530

Publisher: American Society for Microbiology


DOI: 10.1128/JB.183.8.2505-2515.2001

PubMed id: 11274110


Altmetrics provided by Altmetric