title: Stability of mRNA in the hyperthermophilic archaeon Sulfolobus solfataricus.
abstract: Archaea-like bacteria are prokaryotes but, in contrast, use eukaryotic-like systems for key aspects of DNA, RNA, and protein metabolism. mRNA is typically unstable in bacteria and stable in eukaryotes, but little information is available about mRNA half-lives in archaea. Because archaea are generally insensitive to antibiotics, examination of mRNA stability in the hyperthermophile, Sulfolobus solfataricus, required the identification of transcription inhibitors for half-life determinations. An improved lacS promoter-dependent in vitro transcription system was used to assess inhibitor action. Efficient inhibitors were distinguished as blocking both lacSp transcription in vitro and the incorporation of 3H-uracil into bulk RNA in vivo. Actinomycin D was the most stable and potent compound identified. A survey of transcript chemical half-lives normalized to levels of the signal recognition particle 7S RNA ranged from at least 2 h for tfb1, a transcription factor TFIIB paralog, to a minimum of 6.3 min for gln1, one of three glutamine synthetase paralogs. Transcript half-lives for other mRNAs were: 2 h, superoxide dismutase (sod); 37.5 min, glucose dehydrogenase (dhg1); 25 min, alpha-glucosidase (malA); and 13.5 min, transcription factor TFIIB-2 (tfb2) resulting in a minimum average half-life of 54 min. These are the first mRNA half-lives reported for a hyperthermophile or member of the crenarchaea. The unexpected stability of several transcripts has important implications for gene expression and mRNA degradation in this organism.
mesh_terms: D001483:Base Sequence; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D020871:RNA Stability; D019642:RNA, Archaeal / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism*; D012333:RNA, Messenger / Q000737:chemistry* / Q000378:metabolism*; D016944:Sulfolobus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D013696:Temperature; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D019384:Nucleic Acid Synthesis Inhibitors; D019642:RNA, Archaeal; D012333:RNA, Messenger