title: Transcription of the mating-type-regulated lncRNA IRT1 is governed by TORC1 and PKA.
abstract: Cell fate decisions are controlled by multiple cell-intrinsic and -extrinsic factors. In budding yeast, the decision to enter gametogenesis or sporulation is dictated by nutrient availability and mating type. Recently, we showed that in diploid cells harbouring opposite mating types (MATa and MATα), the protein kinase A (PKA) and target of rapamycin complex I (TORC1) signalling pathways integrate at the promoter of the master regulatory transcription factor IME1 to control sporulation via nutrient availability (Weidberg, et al. 2016). In cells with a single mating type (MATa or MATα), however, IME1 is repressed by transcription through the IME1 promoter of a long non-coding RNA called IRT1, which prevents this cell type from undergoing sporulation. Here, we investigated the role of nutrient signalling in mating-type control of IME1. We find that expression of IRT1, like IME1 itself, depends on nutrient availability and the activities of PKA and TORC1. IRT1 transcription is repressed when nutrients are ample and TORC1 and PKA are active. In contrast, inhibition of PKA and TORC1 is sufficient to recruit Rme1 to the IRT1 promoter and induce IRT1-mediated repression of IME1. Finally, we provide evidence that IRT1 and IME1 are co-repressed by the Tup1-Cyc8 complex when nutrients are ample. Thus, in cells with a single mating-type nutrient availability regulates mating-type repression of IME1 and sporulation. Our results indicate that there is a hierarchy between nutrient and mating-type signals in controlling the decision to enter sporulation.
authors: Cell Fate and Gene Regulation Laboratory, The Francis Crick Institute, 44 Lincoln's Inn Fields, London, WC2A 3LY, UK.
authors: Fabien
authors: F
authors: Moretto
authors: Cell Fate and Gene Regulation Laboratory, The Francis Crick Institute, 44 Lincoln's Inn Fields, London, WC2A 3LY, UK. Folkert.vanWerven@crick.ac.uk.
authors: Folkert J
authors: FJ
authors: van Werven
mesh_terms: D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D049770:Genes, Mating Type, Fungal / Q000235:genetics*; D008957:Models, Genetic; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D062085:RNA, Long Noncoding / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D013172:Spores, Fungal / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: C065455:CYC8 protein, S cerevisiae; C080326:IME1 protein, S cerevisiae; D009687:Nuclear Proteins; D062085:RNA, Long Noncoding; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; C561842:TORC1 protein complex, S cerevisiae; C066502:TUP1 protein, S cerevisiae; D014157:Transcription Factors; D017868:Cyclic AMP-Dependent Protein Kinases
keywords: Gametogenesis; IME1; IRT1; Long non-coding RNA; Mating type; Nutrients; Protein kinase A; Rme1; Signalling; Sporulation; TORC1; Transcription; Tup1