title: Small Antisense RNA RblR Positively Regulates RuBisCo inSynechocystissp. PCC 6803.
abstract: Small regulatory RNAs (sRNAs) function as transcriptional and post-transcriptional regulators of gene expression in organisms from all domains of life. Cyanobacteria are thought to have developed a complex RNA-based regulatory mechanism. In the current study, by genome-wide analysis of differentially expressed small RNAs inSynechocystissp. PCC 6803 under high light conditions, we discovered an asRNA (RblR) that is 113nt in length and completely complementary to its target generbcL, which encodes the large chain of RuBisCO, the enzyme that catalyzes carbon fixation. Further analysis of the RblR(+)/(-) mutants revealed that RblR acts as a positive regulator ofrbcLunder various stress conditions; Suppressing RblR adversely affects carbon assimilation and thus the yield, and those phenotypes of both the wild type and the overexpressor could be downgraded to the suppressor level by carbonate depletion, indicated a regulatory role of RblR in CO2assimilation. In addition, a real-time expression platform inEscherichia coliwas setup and which confirmed that RblR promoted the translation of therbcLmRNA into the RbcL protein. The present study is the first report of a regulatory RNA that targets RbcL inSynechocystissp. PCC 6803, and provides strong evidence that RblR regulates photosynthesis by positively modulatingrbcLexpression inSynechocystis.
authors.affiliation: School of Life Sciences, Northwestern Polytechnical University Xi'an, China.
authors.forename: Jinlu
authors.initials: J
authors.lastname: Hu
authors.affiliation: Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of SciencesWuhan, China; University of the Chinese Academy of SciencesBeijing, China.
authors.forename: Tianpei
authors.initials: T
authors.lastname: Li
authors.affiliation: Crop Designing Centre, Henan Academy of Agricultural Sciences Zhengzhou, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Xu
authors.affiliation: Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of Sciences Wuhan, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Zhan
authors.affiliation: Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of Sciences Wuhan, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.affiliation: Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of Sciences Wuhan, China.
authors.forename: Chenliu
authors.initials: C
authors.lastname: He
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, the Chinese Academy of Sciences Wuhan, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
keywords: RblR; RuBisCo; Synechocystis sp. PCC 6803; rbcL; sRNA