A plant-specific transcription factor IIB-related protein, pBRP2, is involved in endosperm growth control Cavel, E. /Pillot, Marion Pontier, D. Lahmy, S. Bies-Etheve, N. Vega, D. /Grimanelli, Daniel Lagrange, T. 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 labelling and GUS staining experiments. Interestingly, pbrp2 loss-of-function specifically affects the development of the syncytial endosperm, with both parental contributions required for wild-type development. pBRP2, is the first B-factor to exhibit cell-specific expression and regulation in eukaryotes, and might play a role in enforcing bi-parental reproduction in angiosperms. 2011 text https://www.documentation.ird.fr/hor/fdi:010053365 fdi:010053365 Cavel E., Pillot Marion, Pontier D., Lahmy S., Bies-Etheve N., Vega D., Grimanelli Daniel, Lagrange T.. A plant-specific transcription factor IIB-related protein, pBRP2, is involved in endosperm growth control. 2011, 6 (2), e17216 EN