,mTERF5 Acts as a Transcriptional Pausing Factor to Positively Regulate Transcription of Chloroplast

• 作 者: Shunhua Ding Yi Zhang Zhi HU Xiahe Huang Bohan Zhang Qingtao Lu Xiaogang Wen Yingchun Wang Congming Lu
• 机 构: Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, Ch
• 出 处: 分子植物（英文版）
• 发表日期: 2019年9期
• 关键词: mTERF5 transcriptional pausing transcription chloroplast psbEFLJ

RNA polymerase transcriptional pausing represents a major checkpoint in transcription in bacteria and metazoans,but it is unknown whether this phenomenon occurs in plant organelles.Here,we report that transcriptional pausing occurs in chloroplasts.We found that mTERF5 specifically and positively regulates the transcription of chloroplast psbEFLJ in Arabidopsis thaliana that encodes four key subunits of photosystem Ⅱ.We found that mTERF5 causes the plastid-encoded RNA polymerase (PEP) complex to pause at psbEFLJ by binding to the +30 to +51 region of double-stranded DNA.Moreover,we revealed that mTERF5 interacts with pTAC6,an essential subunit of the PEP complex,although pTAC6 is not involved in the transcriptional pausing at psbEFLJ.We showed that mTERF5 recruits additional pTAC6 to the transcriptionally paused region ofpsbEFLJ,and the recruited pTAC6 proteins could be assembled into the PEP complex to regulate psbEFLJ transcription.Taken together,our findings shed light on the role of transcriptional pausing in chloroplast transcription in plants.