Endoribonucleases govern the maturation and degradation of RNA and are indispensable in the posttranscriptional regulation of gene expression.A key endoribonuclease in Gram-negative bacteria is RNase E.To ensure an ap...Endoribonucleases govern the maturation and degradation of RNA and are indispensable in the posttranscriptional regulation of gene expression.A key endoribonuclease in Gram-negative bacteria is RNase E.To ensure an appropriate supply of RNase E,some bacteria,such as Escherichia coli,feedback-regulate RNase E expression via the rne 5′-untranslated region(5′UTR)in cis.However,the mechanisms involved in the control of RNase E in other bacteria largely remain unknown.Cyanobacteria rely on solar light as an energy source for photosynthesis,despite the inherent ultraviolet(UV)irradiation.In this study,we first investigated globally the changes in gene expression in the cyanobacterium Synechocystis sp.PCC ^(6)803 after a brief exposure to UV.Among the 407 responding genes 2 h after UV exposure was a prominent upregulation of rne mRNA level.Moreover,the enzymatic activity of RNase E rapidly increased as well,although the protein stability decreased.This unique response was underpinned by the increased accumulation of full-length rne mRNA caused by the stabilization of its 5′UTR and suppression of premature transcriptional termination,but not by an increased transcription rate.Mapping of RNA 3′ends and in vitro cleavage assays revealed that RNase E cleaves within a stretch of six consecutive uridine residues within the rne 5′UTR,indicating autoregulation.These observations suggest that RNase E in cyanobacteria contributes to reshaping the transcriptome during the UV stress response and that its required activity level is secured at the RNA level despite the enhanced turnover of the protein.展开更多
基金supported by Grants-in-Aid 25850056,S2306,and 20K05793 from the Ministry of Education,Culture,Sports,Science and Technology of Japan,the Advanced Low Carbon Technology Research and Development Program(ALCA)of the Japan Science and Technology Agency(JST)(to S.W.)the German Ministry of Education and Research(BMBF),grant no.031L0164B“RNAProNet”(to W.R.H.)+1 种基金the German Science Foundation(DFG)research training group MeInBio 322977937/GRK2344(to A.W.and W.R.H.)grant STE 1119/4-2(to C.S.).
文摘Endoribonucleases govern the maturation and degradation of RNA and are indispensable in the posttranscriptional regulation of gene expression.A key endoribonuclease in Gram-negative bacteria is RNase E.To ensure an appropriate supply of RNase E,some bacteria,such as Escherichia coli,feedback-regulate RNase E expression via the rne 5′-untranslated region(5′UTR)in cis.However,the mechanisms involved in the control of RNase E in other bacteria largely remain unknown.Cyanobacteria rely on solar light as an energy source for photosynthesis,despite the inherent ultraviolet(UV)irradiation.In this study,we first investigated globally the changes in gene expression in the cyanobacterium Synechocystis sp.PCC ^(6)803 after a brief exposure to UV.Among the 407 responding genes 2 h after UV exposure was a prominent upregulation of rne mRNA level.Moreover,the enzymatic activity of RNase E rapidly increased as well,although the protein stability decreased.This unique response was underpinned by the increased accumulation of full-length rne mRNA caused by the stabilization of its 5′UTR and suppression of premature transcriptional termination,but not by an increased transcription rate.Mapping of RNA 3′ends and in vitro cleavage assays revealed that RNase E cleaves within a stretch of six consecutive uridine residues within the rne 5′UTR,indicating autoregulation.These observations suggest that RNase E in cyanobacteria contributes to reshaping the transcriptome during the UV stress response and that its required activity level is secured at the RNA level despite the enhanced turnover of the protein.
