Proteomics-based sequence analysis of plant gene expression – the chloroplast transcription apparatus

• Published in: Phytochemistry (Oxford) Vol. 65; no. 12; pp. 1785 - 1793
• Main Authors: Loschelder, Heike, Homann, Anke, Ogrzewalla, Karsten, Link, Gerhard
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2004
• Subjects: Amino Acid Sequence; amino acid sequences; Base Sequence; casein kinase; Chloroplast transcription; chloroplasts; Chloroplasts - genetics; Chloroplasts - metabolism; Databases, Protein; DNA-directed RNA polymerase; DNA-Directed RNA Polymerases - analysis; DNA-Directed RNA Polymerases - isolation & purification; Gene Expression; gene expression regulation; Mass spectrometry; Molecular Sequence Data; Molecular Weight; mustard; Mustard Plant - genetics; Mustard Plant - metabolism; plant proteins; Plant Proteins - analysis; Plant Proteins - isolation & purification; Protein kinase; protein kinases; Protein-Serine-Threonine Kinases - analysis; proteome; Proteomics; RNA-binding proteins; RNA-Binding Proteins - analysis; RNA-Binding Proteins - isolation & purification; sequence alignment; sequence analysis; Sequence Analysis - methods; Sequence database searches; Sequence Homology, Amino Acid; Sinapis alba; transcription (genetics); transcription factors; Transcription, Genetic; SDR; RBP; SAP; ESI-QTOF; PTK; MALDI-MS; CSP41; RNA-binding proteins; CK2; Sequence database searches; Protein kinase; NEP; PEP; GSH; Chloroplast transcription; Mass spectrometry
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2004.04.034

Database screening helped to identify regulatory proteins of chloroplast RNA polymerase, including a novel putative RNA-binding protein (RBP).The previously identified transcription kinase (cpCK2) is likely to play a common role in number of plant species The chloroplast transcription apparatus has turned out to be more complex than anticipated, with core polypeptides surrounded by multiple accessory proteins of diverse, and in part unexpected, functions. At least two different RNA-binding proteins and several redox-responsive proteins are components of the major chloroplast RNA polymerase termed PEP-A. One of the key-regulatory factors has been identified as a Ser/Thr-specific protein kinase that is sensitive to SH group modification by glutathione and by this means is able to modulate transcription. The cloned plastid transcription kinase from mustard (Sinapis alba L.) has been assigned as a member of the (mostly nucleo-cytosolic) CK2 family and hence has been termed cpCK2. Despite its apparent role in mustard chloroplast transcription, until recently no data have been available for other plant species. Using the web database resources, we find evidence for an evolutionarily conserved role of this redox-sensitive plastid transcription factor.