title: Antisense-mediated FLC transcriptional repression requires the P-TEFb transcription elongation factor.
abstract: The functional significance of noncoding transcripts is currently a major question in biology. We have been studying the function of a set of antisense transcripts called COOLAIR that encompass the whole transcription unit of the Arabidopsis floral repressor FLOWERING LOCUS C (FLC). Alternative polyadenylation of COOLAIR transcripts correlates with different FLC sense expression states. Suppressor mutagenesis aimed at understanding the importance of this sense-antisense transcriptional circuitry has identified a role for Arabidopsis cyclin-dependent kinase C (CDKC;2) in FLC repression. CDKC;2 functions in an Arabidopsis positive transcription elongation factor b (P-TEFb) complex and influences global RNA polymerase II (Pol II) Ser(2) phosphorylation levels. CDKC;2 activity directly promotes COOLAIR transcription but does not affect an FLC transgene missing the COOLAIR promoter. In the endogenous gene context, however, the reduction of COOLAIR transcription by cdkc;2 disrupts a COOLAIR-mediated repression mechanism that increases FLC expression. This disruption then feeds back to indirectly increase COOLAIR expression. This tight interconnection between sense and antisense transcription, together with differential promoter sensitivity to P-TEFb, is central to quantitative regulation of this important floral repressor gene.
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom; andKey Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China.
authors.forename: Zhi-Wei
authors.initials: ZW
authors.lastname: Wang
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom; and.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom; and.
authors.forename: Oleg
authors.initials: O
authors.lastname: Raitskin
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom; and.
authors.forename: Qianwen
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom; and caroline.dean@jic.ac.uk.
authors.forename: Caroline
authors.initials: C
authors.lastname: Dean
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D005816:Genetic Complementation Test; D026161:MADS Domain Proteins / Q000235:genetics*; D009154:Mutation; D016376:Oligonucleotides, Antisense / Q000235:genetics*; D010766:Phosphorylation; D030821:Plants, Genetically Modified; D042925:Positive Transcriptional Elongation Factor B / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000235:genetics; D019076:Transgenes
chemical_list: D029681:Arabidopsis Proteins; D002843:Chromatin; C418902:At5g10140 protein, Arabidopsis; D026161:MADS Domain Proteins; D016376:Oligonucleotides, Antisense; D012097:Repressor Proteins; D042925:Positive Transcriptional Elongation Factor B; C523217:CDKC;2 protein, Arabidopsis; D018844:Cyclin-Dependent Kinases
keywords: autonomous pathway; chromatin silencing; lncRNA; transcriptional regulation