Abstract
The moderately halophilic archaeon Haloferax volcanii was surveyed for protein profile changes correlated with growth at high and low salinity. A single polypeptide with an approximate mass of 46 kDa was conspicuously more abundant during growth at high salinity. This protein was identified as HMG-CoA reductase (HMGR), encoded by the hmgR gene. HMGR is a key enzyme in the mevalonate pathway of isoprenoid biosynthesis, the sole route in haloarchaea for lipid and carotenoid production. Enzymatic assays confirmed that HMGR activity is more abundant in cells grown at high salinity. Low salt cultures of H. volcanii contained lower amounts of hmgR transcript compared to cells grown in high salt suggesting that the observed regulation occurs at the level of transcription. Paradoxically, both lipid and carotenoid content decreased in H. volcanii grown at high salinity despite the increased levels of HMGR specific activity. To our knowledge, this is the first report demonstrating that the expression of HMGR is regulated in response to non-optimal salinity in a halophilic archaeon.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.