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Regulation of plastid rDNA transcription by interaction of CDF2 with two different RNA polymerases
Author(s) -
Bligny Muriel,
Courtois Florence,
Thaminy Safia,
Chang ChingChun,
Lagrange Thierry,
BaruahWolff Jahnabi,
Stern David,
LerbsMache Silva
Publication year - 2000
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/19.8.1851
Subject(s) - biology , rna polymerase , transcription (linguistics) , rna polymerase i , operon , rna polymerase ii , sigma factor , promoter , genetics , transcriptional regulation , plastid , polymerase , transcription factor ii d , rna , microbiology and biotechnology , transcription factor , gene , gene expression , chloroplast , linguistics , philosophy , escherichia coli
The plastid genome is known to be transcribed by a plastid‐encoded prokaryotic‐type RNA polymerase (PEP) and by a nucleus‐encoded phage‐type RNA polymerase (NEP). The spinach plastid rrn operon promoter region harbours three different, overlapping promoters. Two of them are of the prokaryotic type. The third promoter is a non‐consensus‐type NEP promoter. We separated three different transcriptional activities from spinach chloroplasts: PEP, the phage‐type RNA polymerase NEP‐1, and a third, hitherto undescribed transcriptional activity (NEP‐2). NEP‐2 specifically transcribes the rrn operon in the presence of the transcription factor CDF2. CDF2 was previously shown to recruit PEP to the rrn promoter to repress transcription. Together, our results suggest the existence of a third RNA polymerase in plastids and a mechanism of rDNA transcriptional regulation that is based on the interaction of the transcription factor CDF2 with two different transcriptional systems.