Regulatory system for light-responsive gene expression in photosynthesizing bacteria: cis-elements and trans-acting factors in transcription and post-transcription.
Cyanobacteria (blue-green algae) are photosynthesizing organisms that can be used as a model for analyzing light-responsive gene expression. The regulatory system of the light-responsive psbA gene with cis-elements and trans-acting factors was studied at both transcriptional and post-transcriptional levels. Positive regulation comprises DNA curvatures (CIT and RIB), upstream elements (UPE and promoter), and a light-induced sigma factor (SigD) of RNA polymerase in transcription. On the other hand, negative regulation involves mRNA instability through an AU-box under darkness. This two-step process is a candidate for a novel mechanism regulating light-responsive gene expression.
Asayama
Munehiko
M
Laboratory of Molecular Genetics, Ibaraki University, Japan. asam@mx.ibaraki.ac.jp
D000458:Cyanobacteria / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics* / Q000528:radiation effects*; D008027:Light; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics / Q000528:radiation effects*
D045332:Photosystem II Protein Complex; C422369:photosystem II, psbA subunit