Budding yeast RNA polymerase II CTD phosphorylation and transcription termination factor localization
ABSTRACT: Whole genome analysis of total RNA pol II, Ser2-, Ser5- and Ser7-phosphorylated RNA pol II, in WT and mutants of the C-terminal domain (CTD) kinases Ctk1 and Kin28, and localization of the termination factors Pcf11, Nrd1 and Rat1. ChIP-chip using ligation-mediated PCR-amplified material hybridized to NimbleGen 385K arrays (50mers, median probe spacing 32 bp, cat. No. C4214-00-01).
Phosphorylation of the RNA polymerase (Pol) II C-terminal domain (CTD) repeats (1-YSPTSPS-7) is coupled to transcription and may act as a 'code' that controls mRNA synthesis and processing. To examine the code in budding yeast, we mapped genome-wide CTD Ser2, Ser5 and Ser7 phosphorylations and the CTD-associated termination factors Nrd1 and Pcf11. Phospho-CTD dynamics are not scaled to gene length and are gene-specific, with highest Ser5 and Ser7 phosphorylation at the 5' ends of well-expressed ...[more]
Project description:The rate of RNA polymerase II (pol II) elongation can influence splice site selection in nascent transcripts, yet the extent and physiological relevance of this kinetic coupling between transcription and alternative splicing is not well understood. We performed experiments to perturb pol II elongation and then globally compared alternative splicing patterns with genome-wide pol II occupancy. RNA binding and RNA processing functions were significantly enriched among the genes with pol II elongation inhibition-dependent changes in alternative splicing. Under conditions that interfere with pol II elongation, including cell stress, increased pol II occupancy was detected in the intronic regions flanking the alternative exons in these genes, and these exons generally became more included. A disproportionately high fraction of these exons introduced premature termination codons that elicited nonsense-mediated mRNA decay (NMD), thereby further reducing transcript levels. Our results provide evidence that kinetic coupling between transcription, alternative splicing and NMD affords a rapid mechanism by which cells can respond to changes in growth conditions, including cell stress, to coordinate the levels of RNA processing factors with mRNA levels. To monitor pol II distributions, chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-Seq) was performed using an anti-pol II antibody (4H8) and cross-linked chromatin preparations from Jurkat cells, treated with or without pol II elongation inhibitor 5,6-dichloro-1-β-D-ribofuranosyl-benzimidazole (DRB) at 10 and 25 ug/ml respectively prior to phorbol 12-myristate 13-acetate (PMA) stimulation, for 5000+ alternative splicing events.
Project description:We report genome-wide detection of long noncoding RNA (lncRNA) generate by Pol V in transcriptional gene silencing in Arabidopsis thaliana. We further show that most of these transcripts are bound by AGO4. RNA immunoprecipitation followed by high-throughput sequencing (RIP-seq) RNA immunoprecipitation with an anti-AGO4 antibody was performed in one biological replicate and included Col-0, nrpe1, and ago4-1; RNA immunoprecipitation with an anti-NRPE1 (largest subunit of Pol V) was performed in two replicates; replicate 1 included Col-0 and nrpe1, replicated two included Col-0, nrpe1, ago4-1, and idn2-1
Project description:Germ cells employ elaborate mechanisms to maintain and protect their genetic material, and also to regulate gene expression during the complex differentiation process of gametogenesis. Piwi proteins, a subclade of the Argonaute family, are expressed mainly in the germline and bind piRNAs, a novel and diverse class of small RNAs whose biogenesis and putative functions are still largely elusive. We employed High Throughput Sequencing after Crosslinking and Immunoprecipitation (HITS-CLIP) coupled with RNA-Seq to characterize the genome-wide target RNA repertoire of Mili and Miwi, two mouse Piwi proteins. Our analysis outlines a model for primary piRNA biogenesis in postnatal mouse and indicates that piRNAs do not mediate target RNA recognition, but rather are the end products of RNA processing. Moreover, we identify a set of mRNAs essential for spermiogenesis that are bound and regulated by Miwi, directly implicating Piwi proteins in the control of gene expression at key time points of spermiogenesis. HITS-CLIP (High Throughput Sequencing after Crosslinking and Immunoprecipitation) experiments targeting two mouse Piwi proteins Mili and Miwi.
Project description:We examined genome-wide variation in transcription factor binding in different individuals and a chimpanzee using chromatin immunoprecipitation followed by massively-parallel sequencing (ChIP-Seq). The binding sites of RNA Polymerase II (Pol II) as well as a key regulator of immune responses, NFkB, were mapped in ten HapMap lymphoblastoid cell lines derived from individuals of African, European, and Asian ancestry, including a parent-offspring trio. We also mapped gene expression in all ten human cell lines for two treatment conditions: a) no treatment and b) following induction by TNF-alpha. Genome-wide comparison of Pol II and NF-KappaB binding in ten individuals. ChIP-seq with NF-KappaB.
Project description:whole genome analysis of RNA pol II and histone H3 in WT and Spt6-depleted cells using a tetracycline regulated ts degron mutant, spt6-td. ChiP-ChIP using ligation-mediated PCR amplified material hybridized to Nimblegen 385K arrays 50mers median probe spacing 32 bp cat. No. C4214-00-01
Project description:Asf1, through its histone chaperone activity, helps chromatin closing/opening during DNA replication, repair, recombination and transcription. Despite extensive research on Asf1-mediated physiological functions, a genome-wide localization map is lacking, limiting our knowledge of chromosomal features targeted by Asf1. We present a high-resolution genome-wide map of Asf1, localizing at essentially all pol III-transcribed genes, highly active pol II-transcribed genes and heterochromatic features. Pol III-transcribed genes are negatively regulated by Asf1, whereas pol II genes are regulated indirectly by Asf1-dependent H3K56 acetylation. Interestingly, Asf1 localization along yeast chromosomes shows nearly identical distribution to that of the condensin complex, predicting a functional overlap in chromosome architecture and genome organization. ChIP-seq analysis of Asf1 targets using a yeast strain that expresses an 18-Myc tag fused to the C-terminus of ASF1. Two biological replicates and one mock/control were performed. The Illumina GAII was used. ChIP-seq reads are aligned to the budding yeast sacCer3 (2011) assembly.