title: Glutamyl-tRNA mediates a switch in RNA polymerase use during chloroplast biogenesis.
abstract: Chloroplast genes of higher plants are transcribed by two types of RNA polymerase that are encoded by nuclear (NEP (nuclear-encoded plastid RNA polymerase)) or plastid (PEP (plastid-encoded plastid RNA polymerase)) genomes. NEP is largely responsible for the transcription of housekeeping genes during early chloroplast development. Subsequent light-dependent chloroplast maturation is accompanied by repression of NEP activity and activation of PEP. Here, we show that the plastid-encoded transfer RNA for glutamate, the expression of which is dependent on PEP, directly binds to and inhibits the transcriptional activity of NEP in vitro. The plastid tRNA(Glu) thus seems to mediate the switch in RNA polymerase usage from NEP to PEP during chloroplast development.
authors.affiliation: Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
authors.forename: Mitsumasa
authors.initials: M
authors.lastname: Hanaoka
authors.forename: Kengo
authors.initials: K
authors.lastname: Kanamaru
authors.forename: Makoto
authors.initials: M
authors.lastname: Fujiwara
authors.forename: Hideo
authors.initials: H
authors.lastname: Takahashi
authors.forename: Kan
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D002736:Chloroplasts / Q000201:enzymology*; D003001:Cloning, Molecular; D017931:DNA Primers; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004789:Enzyme Activation / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense; D012346:RNA, Transfer, Amino Acyl / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D017931:DNA Primers; D016376:Oligonucleotides, Antisense; D012346:RNA, Transfer, Amino Acyl; D012321:DNA-Directed RNA Polymerases