a plant-specific transcription factor iib-related protein, pbrp2, is involved in endosperm growth control植物转录因子iib-related蛋白质,pbrp2,参与控制胚乳的增长.pdfVIP

A Plant-Specific Transcription Factor IIB-Related Protein, pBRP2, Is Involved in Endosperm Growth Control 1¤ 2 1 1 1 Emilie Cavel , Marion Pillot , Dominique Pontier , Sylvie Lahmy , Natacha Bies-Etheve , Danielle 1 2 1 Vega , Daniel Grimanelli *, Thierry Lagrange * ´ ´ ´ ´ 1 Laboratoire Genome et Developpement des Plantes, Centre National de la Recherche Scientifique/Institut de Recherche pour le Developpement/Universite de ´ Perpignan, Perpignan, France, 2 Institut de Recherche pour le Developpement, Montpellier, France Abstract General transcription factor IIB (TFIIB) and TFIIB-related factor (BRF), are conserved RNA polymerase II/III (RNAPII/III) selectivity factors that are involved in polymerase recruitment and transcription initiation in eukaryotes. Recent findings have shown that plants have evolved a third type of B-factor, plant-specific TFIIB-related protein 1 (pBRP1), which seems to be involved in RNAPI transcription. Here, we extend the repertoire of B-factors in plants by reporting the characterization of a novel TFIIB-related protein, plant-specific TFIIB-related protein 2 (pBRP2), which is found to date only in the Brassicacea family. Unlike other B-factors that are ubiquitously expressed, PBRP2 expression is restricted to reproductive organs and seeds as shown by RT-PCR, immunofluorescence labe