Budding yeast Cdc13, Stn1, and Ten1 form the CST complex to protect telomeres from lethal DNA degradation. It remains unknown whether similar complexes are conserved in higher eukaryotes or not. Here we isolated mammalian STN1 and TEN1 homologs and CTC1 (conserved telomere maintenance component 1). The three proteins contain putative OB-fold domains and form a complex called CST, which binds to single-stranded DNA with high affinity in a sequence-independent manner. CST associates with a fraction of telomeres consistently during the cell cycle, in quiescent cells and Pot1-knockdown cells. It does not colocalize with replication foci in S phase. Significant increases in the abundance of single-stranded G-strand telomeric DNA were observed in Stn1-knockdown cells. We propose that CST is a replication protein A (RPA)-like complex that is not directly involved in conventional DNA replication at forks but plays a role in DNA metabolism frequently required by telomeres.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.molcel.2009.08.009 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
DHX15 and Rig-I Coordinate Apoptosis and Innate Immune Signaling by Antiviral RNase L.
Viruses
December 2024
Department of Biological Sciences, University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606, USA.
During virus infection, the activation of the antiviral endoribonuclease, ribonuclease L (RNase L), by a unique ligand 2'-5'-oilgoadenylate (2-5A) causes the cleavage of single-stranded viral and cellular RNA targets, restricting protein synthesis, activating stress response pathways, and promoting cell death to establish broad antiviral effects. The immunostimulatory dsRNA cleavage products of RNase L activity (RL RNAs) recruit diverse dsRNA sensors to activate signaling pathways to amplify interferon (IFN) production and activate inflammasome, but the sensors that promote cell death are not known. In this study, we found that DEAH-box polypeptide 15 (DHX15) and retinoic acid-inducible gene I (Rig-I) are essential for apoptosis induced by RL RNAs and require mitochondrial antiviral signaling (MAVS), c-Jun amino terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38 MAPK) for caspase-3-mediated intrinsic apoptosis.
View Article and Find Full Text PDFAffinity Tag-Free Purification of SARS-CoV-2 N Protein and Its Crystal Structure in Complex with ssDNA.
Biomolecules
November 2024
Cancer Innovation Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.
The nucleocapsid (N) protein is one of the four structural proteins in SARS-CoV-2, playing key roles in viral assembly, immune evasion, and stability. One of its primary functions is to protect viral RNA by forming the nucleocapsid. However, the precise mechanisms by which the N protein interacts with viral RNA and assembles into a nucleocapsid remain unclear.
View Article and Find Full Text PDFDNA binding of an RNA helicase bacterial transcription terminator.
Biochem J
January 2025
Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India.
The bacterial transcription terminator Rho is a hexameric ATP-dependent RNA helicase that dislodges elongating RNA polymerases. It has an N-terminal primary RNA binding site (PBS) on each subunit and a C-terminal secondary RNA binding site at the central channel. Here, we show that Rho also binds to linear longer double-stranded DNAs (dsDNA) and the circular plasmids non-specifically using its PBS.
View Article and Find Full Text PDFBacterial Shedu immune nucleases share a common enzymatic core regulated by diverse sensor domains.
Mol Cell
December 2024
Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA; Department of Molecular Biology, University of California, San Diego, La Jolla, CA, USA. Electronic address:
Prokaryotes possess diverse anti-bacteriophage immune systems, including the single-protein Shedu nuclease. Here, we reveal the structural basis for activation of Bacillus cereus Shedu. Two cryoelectron microscopy structures of Shedu show that it switches between inactive and active states through conformational changes affecting active-site architecture, which are controlled by the protein's N-terminal domain (NTD).
View Article and Find Full Text PDFThe HNH endonuclease domain of the giant virus MutS7 specifically binds to branched DNA structures with single-stranded regions.
DNA Repair (Amst)
December 2024
Agriculture and Marine Science Program, Graduate School of Integrated Arts and Science, Kochi University, Nankoku, Kochi 783-8502, Japan; Agricultural Science, Graduate School of Integrated Arts and Science, Kochi University, Nankoku, Kochi 783-8502, Japan. Electronic address:
Most giant viruses including Mimiviridae family build large viral factories within the host cytoplasms. These giant viruses are presumed to possess specific genes that enable the rapid and massive replication of their large double-stranded DNA genomes within viral factories. It has been revealed that a functionally uncharacterized protein, MutS7, is expressed during the operational phase of the viral factory.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!