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Regulation of SirT1-Nucleomethylin Binding by rRNA Coordinates Ribosome Biogenesis with Nutrient Availability
- Source :
- Molecular and Cellular Biology. 33:3835-3848
- Publication Year :
- 2013
- Publisher :
- Informa UK Limited, 2013.
-
Abstract
- Nucleomethylin (NML), a novel nucleolar protein, is important for mediating the assembly of the energy-dependent nucleolar silencing complex (eNoSC), which also contains SirT1 and SUV39H1. eNoSC represses rRNA transcription during nutrient deprivation, thus reducing energy expenditure and improving cell survival. We found that NML is an RNA binding protein that copurifies with 5S, 5.8S, and 28S rRNA. The SirT1 and RNA binding regions on NML showed partial overlap, and the NML-SirT1 interaction was competitively inhibited by rRNA. Nutrient deprivation triggered downregulation of rRNA transcription, reduced the level of NML-associated rRNA, and stimulated NML-SirT1 binding. Assembly of eNoSC facilitated repression of pre-rRNA transcription. These results suggest that nascent rRNA generates a positive-feedback signal by suppressing the assembly of eNoSC and protecting active ribosomal DNA units from heterochromatin formation. This RNA-mediated mechanism enables the eNoSC to amplify the effects of upstream nutrient-responsive regulators.
- Subjects :
- Blotting, Western
Molecular Sequence Data
Gene Expression
Ribosome biogenesis
Biology
Ribosome
Sirtuin 1
23S ribosomal RNA
Transcription (biology)
Cell Line, Tumor
RNA, Ribosomal, 28S
Humans
Amino Acid Sequence
Molecular Biology
Ribosomal DNA
Sequence Homology, Amino Acid
Reverse Transcriptase Polymerase Chain Reaction
RNA, Ribosomal, 5S
Nuclear Proteins
RNA-Binding Proteins
RNA
Methyltransferases
Articles
Cell Biology
Ribosomal RNA
Molecular biology
RRNA transcription
RNA, Ribosomal, 5.8S
Cell biology
Glucose
RNA, Ribosomal
RNA Interference
Ribosomes
HeLa Cells
Protein Binding
Subjects
Details
- ISSN :
- 10985549
- Volume :
- 33
- Database :
- OpenAIRE
- Journal :
- Molecular and Cellular Biology
- Accession number :
- edsair.doi.dedup.....67621525aee1cad913403f981ee0a86f