Project description:This study identified LEAFY (LFY) as a pioneer transcription factor. We made use of 35S:LFY-GR, an inducible version of the LFY protein fused to the rat glucocorticoid hormone binding domain. In root explants, steroid activated LFY-GR triggers synchronous and abundant flower induction (PMID: 15225291). We combined LFY ChIP-seq, MNase-seq before and after LFY binding and time-course RNA-seq in 35S:LFY-GR root explants to characterize the role of LFY as a pioneer transcription factor.
Project description:This study identified LEAFY (LFY) as a pioneer transcription factor. We made use of 35S:LFY-GR, an inducible version of the LFY protein fused to the rat glucocorticoid hormone binding domain. In root explants, steroid activated LFY-GR triggers synchronous and abundant flower induction (PMID: 15225291). We combined LFY ChIP-seq, MNase-seq before and after LFY binding and time-course RNA-seq in 35S:LFY-GR root explants to characterize the role of LFY as a pioneer transcription factor.
Project description:This study identified LEAFY (LFY) as a pioneer transcription factor. We made use of 35S:LFY-GR, an inducible version of the LFY protein fused to the rat glucocorticoid hormone binding domain. In root explants, steroid activated LFY-GR triggers synchronous and abundant flower induction (PMID: 15225291). We combined LFY ChIP-seq, MNase-seq before and after LFY binding and time-course RNA-seq in 35S:LFY-GR root explants to characterize the role of LFY as a pioneer transcription factor.
Project description:The nucleosome is a fundamental unit of chromatin in eukaryotes, and generally prevents the binding of transcription factors to genomic DNA. Pioneer transcription factors overcome the nucleosome barrier, and bind their target DNA sequences in chromatin. OCT4 is a representative pioneer transcription factor that plays a role in stem cell pluripotency. In the present study, we biochemically analyzed the nucleosome binding by OCT4. Crosslinking mass spectrometry showed that OCT4 binds the nucleosome.
Project description:The aim of this experiment is to test the ability of the ortholog of Arabidopsis LFY gene from flowering and non flowering species to complement an Arabidopsis LFY mutant. <br>Plants expressing, in a homozygous lfy12 background, the open reading frame of LFY orthologs under the control of Arabidopsis LFY promoter were synchronously induced to flower by growing plants in short days for 30 days then shifting them to Long Day for an additional 8 days. Shoot apices were dissected at either d0 or d8 in long days. Two biological replicates were performed. The following genotypes were used: <br>Col - wild type arabidopsis; reference strain<br>LFY (lfy12; LFY::AthLFY) - Arabidopsis<br>UNI (lfy12; LFY::UNI) - Pisum<br>ALF (lfy12; LFY::ALF) - Petunia <br>WelNDLY (lfy12; LFY::WelNDLY) - Welwitschia mirabilis<br>CrLFY1 (lfy12; LFY::CrLFY1) - Ceratopteris richardii<br>CrLFY2 (lfy12; LFY::CrLFY2) - Ceratopteris richardii<br>lfy-2; weak lfy allele<br>lfy-9; intermediate leafy allele<br>lfy-12; strong leafy allele.
Project description:Multicellular organisms develop new structures by initiating specific gene regulatory programs through coordinated changes at the transcriptional and chromatin levels. Master transcription factors orchestrate such global changes but the underlying molecular mechanisms remain unclear. Here we focus on LEAFY (LFY), a key regulator of flower development in angiosperms. The resolution of the crystallographic structure of its N-terminal domain shows that it forms an unanticipated Sterile Alpha Motif (SAM) domain. This domain drives LFY oligomerization, which we establish to be essential for LFY floral switch function. Combining in vitro and in vivo experiments, we demonstrate that oligomerization facilitates LFY binding to DNA regions with multiple binding sites. Moreover, genome-wide analyses reveal an additional prominent role for the oligomerization domain: it confers upon LFY the capacity to bind to closed chromatin regions. This novel property, combined with its previously demonstrated capacity to recruit chromatin remodelers, indicates that LFY controls floral fate by acting as a plant pioneer transcription factor.