title: Regulation of transcription termination in the nematode Caenorhabditis elegans.
abstract: The current predicted mechanisms that describe RNA polymerase II (pol II) transcription termination downstream of protein expressing genes fail to adequately explain, how premature termination is prevented in eukaryotes that possess operon-like structures. Here we address this issue by analysing transcription termination at the end of single protein expressing genes and genes located within operons in the nematode Caenorhabditis elegans. By using a combination of RT-PCR and ChIP analysis we found that pol II generally transcribes up to 1 kb past the poly(A) sites into the 3' flanking regions of the nematode genes before it terminates. We also show that pol II does not terminate after transcription of internal poly(A) sites in operons. We provide experimental evidence that five randomly chosen C. elegans operons are transcribed as polycistronic pre-mRNAs. Furthermore, we show that cis-splicing of the first intron located in downstream positioned genes in these polycistronic pre-mRNAs is critical for their expression and may play a role in preventing premature pol II transcription termination.
authors.affiliation: Genetics Unit, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Haenni
authors.forename: Helen E
authors.initials: HE
authors.lastname: Sharpe
authors.forename: Maria
authors.initials: M
authors.lastname: Gravato Nobre
authors.forename: Kerstin
authors.initials: K
authors.lastname: Zechner
authors.forename: Cathy
authors.initials: C
authors.lastname: Browne
authors.forename: Jonathan
authors.initials: J
authors.lastname: Hodgkin
authors.forename: André
authors.initials: A
authors.lastname: Furger
mesh_terms: D000818:Animals; D002107:Caenorhabditis / Q000235:genetics*; D004257:DNA Polymerase II / Q000378:metabolism*; D005786:Gene Expression Regulation; D007438:Introns; D009876:Operon; D034622:RNA Interference; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000037:antagonists & inhibitors; D020040:Trans-Splicing; D014158:Transcription, Genetic
chemical_list: D012333:RNA, Messenger; D017412:Ribonucleoprotein, U1 Small Nuclear; D004257:DNA Polymerase II