title: S1 domain-containing STF modulates plastid transcription and chloroplast biogenesis in Nicotiana benthamiana.
abstract: • In this study, we examined the biochemical and physiological functions of Nicotiana benthamiana S1 domain-containing Transcription-Stimulating Factor (STF) using virus-induced gene silencing (VIGS), cosuppression, and overexpression strategies. • STF : green fluorescent protein (GFP) fusion protein colocalized with sulfite reductase (SiR), a chloroplast nucleoid-associated protein also present in the stroma. Full-length STF and its S1 domain preferentially bound to RNA, probably in a sequence-nonspecific manner. • STF silencing by VIGS or cosuppression resulted in severe leaf yellowing caused by disrupted chloroplast development. STF deficiency significantly perturbed plastid-encoded multimeric RNA polymerase (PEP)-dependent transcript accumulation. Chloroplast transcription run-on assays revealed that the transcription rate of PEP-dependent plastid genes was reduced in the STF-silenced leaves. Conversely, the exogenously added recombinant STF protein increased the transcription rate, suggesting a direct role of STF in plastid transcription. Etiolated seedlings of STF cosuppression lines showed defects in the light-triggered transition from etioplasts to chloroplasts, accompanied by reduced light-induced expression of plastid-encoded genes. • These results suggest that STF plays a critical role as an auxiliary factor of the PEP transcription complex in the regulation of plastid transcription and chloroplast biogenesis in higher plants.
authors: Department of Systems Biology, Yonsei University, Seoul, Korea.
authors: Young
authors: Y
authors: Jeon
authors: Hyun Ju
authors: HJ
authors: Jung
authors: Hunseung
authors: H
authors: Kang
authors: Youn-Il
authors: YI
authors: Park
authors: Soon Hee
authors: SH
authors: Lee
authors: Hyun-Sook
authors: HS
authors: Pai
mesh_terms: D002736:Chloroplasts / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D024202:Electrophoretic Mobility Shift Assay; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing / Q000528:radiation effects; D007425:Intracellular Membranes / Q000378:metabolism / Q000528:radiation effects / Q000648:ultrastructure; D008027:Light; D008969:Molecular Sequence Data; D010641:Phenotype; D010788:Photosynthesis / Q000528:radiation effects; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000528:radiation effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism / Q000528:radiation effects; D013489:Suppression, Genetic / Q000528:radiation effects; D020524:Thylakoids / Q000648:ultrastructure; D014026:Nicotiana / Q000235:genetics* / Q000528:radiation effects / Q000648:ultrastructure; D014158:Transcription, Genetic / Q000528:radiation effects
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins