Transcriptional control of photosynthesis genes: the evolutionarily conserved regulatory mechanism in plastid genome function.

ABSTRACT: Chloroplast sensor kinase (CSK) is a bacterial-type sensor histidine kinase found in chloroplasts--photosynthetic plastids--in eukaryotic plants and algae. Using a yeast two-hybrid screen, we demonstrate recognition and interactions between: CSK, plastid transcription kinase (PTK), and a bacterial-type RNA polymerase sigma factor-1 (SIG-1). CSK interacts with itself, with SIG-1, and with PTK. PTK also interacts directly with SIG-1. PTK has previously been shown to catalyze phosphorylation of plastid-encoded RNA polymerase (PEP), suppressing plastid transcription nonspecifically. Phospho-PTK is inactive as a PEP kinase. Here, we propose that phospho-CSK acts as a PTK kinase, releasing PTK repression of chloroplast transcription, while CSK also acts as a SIG-1 kinase, blocking transcription

SUBMITTER: Puthiyaveetil S 

PROVIDER: S-EPMC3012001 | biostudies-literature | 2010

REPOSITORIES: biostudies-literature