title: The β-1,3-glucanosyltransferase Gas1 regulates Sir2-mediated rDNA stability in Saccharomyces cerevisiae.
abstract: In Saccharomyces cerevisiae, the stability of highly repetitive rDNA array is maintained through transcriptional silencing. Recently, a β-1,3-glucanosyltransferase Gas1 has been shown to play a significant role in the regulation of transcriptional silencing in S. cerevisiae. Here, we show that the gas1Δ mutation increases rDNA silencing in a Sir2-dependent manner. Remarkably, the gas1Δ mutation induces nuclear localization of Msn2/4 and stimulates the expression of PNC1, a gene encoding a nicotinamidase that functions as a Sir2 activator. The lack of enzymatic activity of Gas1 or treatment with a cell wall-damaging agent, Congo red, exhibits effects similar to those of the gas1Δ mutation. Furthermore, the loss of Gas1 or Congo red treatment lowers the cAMP-dependent protein kinase (PKA) activity in a cell wall integrity MAP kinase Slt2-dependent manner. Collectively, our results suggest that the dysfunction of Gas1 plays a positive role in the maintenance of rDNA integrity by decreasing PKA activity and inducing the accumulation of Msn2/4 in the nucleus. It seems that nuclear-localized Msn2/4 stimulate the expression of Pnc1, thereby enhancing the association of Sir2 with rDNA and promoting rDNA stability.
authors: Department of Biological Sciences and Research Center for Functional Cellulomics, Institute of Microbiology, Seoul National University, Seoul 151-747, Republic of Korea.
authors: Cheol Woong
authors: CW
authors: Ha
authors: Department of Biological Sciences and Research Center for Functional Cellulomics, Institute of Microbiology, Seoul National University, Seoul 151-747, Republic of Korea.
authors: Kwantae
authors: K
authors: Kim
authors: Department of Biological Sciences and Research Center for Functional Cellulomics, Institute of Microbiology, Seoul National University, Seoul 151-747, Republic of Korea.
authors: Yeon Ji
authors: YJ
authors: Chang
authors: Department of Biological Sciences and Research Center for Functional Cellulomics, Institute of Microbiology, Seoul National University, Seoul 151-747, Republic of Korea.
authors: Bongkeun
authors: B
authors: Kim
authors: Department of Biological Sciences and Research Center for Functional Cellulomics, Institute of Microbiology, Seoul National University, Seoul 151-747, Republic of Korea wkh@snu.ac.kr.
authors: Won-Ki
authors: WK
authors: Huh
mesh_terms: D003224:Congo Red; D004275:DNA, Ribosomal; D004268:DNA-Binding Proteins / Q000378:metabolism; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D020868:Gene Silencing; D004693:Glucan Endo-1,3-beta-D-Glucosidase / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009535:Nicotinamidase / Q000096:biosynthesis; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae / Q000378:metabolism*; D056565:Sirtuin 2 / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D004275:DNA, Ribosomal; D004268:DNA-Binding Proteins; C066709:GAS1 protein, S cerevisiae; C081935:MSN2 protein, S cerevisiae; C081937:MSN4 protein, S cerevisiae; D008562:Membrane Glycoproteins; D029701:Saccharomyces cerevisiae Proteins; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae; D014157:Transcription Factors; D003224:Congo Red; D020928:Mitogen-Activated Protein Kinases; C072724:SLT2 protein, S cerevisiae; C117939:1,3-beta-glucanosyltransferase; D004693:Glucan Endo-1,3-beta-D-Glucosidase; C087778:SIR2 protein, S cerevisiae; D056565:Sirtuin 2; D009535:Nicotinamidase; C474330:PNC1 protein, S cerevisiae