- 著者
- Hazuki Hasegawa Tatsuhiro Tsurumaki Ikki Kobayashi Sousuke Imamura Kan Tanaka
- 出版者
- Applied Microbiology, Molecular and Cellular Biosciences Research Foundation
- 雑誌
- The Journal of General and Applied Microbiology (ISSN:00221260)
- 巻号頁・発行日
- pp.2019.05.002, (Released:2019-09-10)
- 参考文献数
- 34
- 被引用文献数
- 5
Proteins that bind to RNA polymerase (RNAP) sigma factors play important roles in various transcriptional regulations. In this study, we identified a candidate of the principal sigma factor interacting protein in cyanobacteria, named SinA, based on a previous comprehensive protein interaction study (Sato et al., 2007) and analyzed this in the cyanobacterium Synechococcus elongatus PCC 7942. SinA is highly conserved among cyanobacteria and a knock out mutant showed defective growth at a usually permissive high temperature (40°C). Because this observation suggested SinA involvement in heat-inducible transcriptional activation, we examined heat-inducible protein gene hspA expression after temperature upshifts. The second-step induction disappeared after 15 min in the sinA mutant. In vivo pull-down experiments demonstrated the interaction between SinA and the principal sigma factor RpoD1. This SinA-RpoD1 complex was associated with an RNAP core enzyme under growth temperatures, but was dissociated after a temperature upshift. Based on these results, we propose a function of SinA to facilitate the substitution of the principal sigma factor with alternative sigma factors under heat-stressed conditions.