Small tandem duplications of DNA occur frequently in the human genome and are implicated in the aetiology of certain human cancers. Recent studies have suggested that DNA double-strand breaks are causal to this mutational class, but the underlying mechanism remains elusive. Here, we identify a crucial role for DNA polymerase α (Pol α)-primase in tandem duplication formation at breaks having complementary 3' ssDNA protrusions. By including so-called primase deserts in CRISPR/Cas9-induced DNA break configurations, we reveal that fill-in synthesis preferentially starts at the 3' tip, and find this activity to be dependent on 53BP1, and the CTC1-STN1-TEN1 (CST) and Shieldin complexes. This axis generates near-blunt ends specifically at DNA breaks with 3' overhangs, which are subsequently repaired by non-homologous end-joining. Our study provides a mechanistic explanation for a mutational signature abundantly observed in the genomes of species and cancer cells.
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http://dx.doi.org/10.1038/s41467-021-25154-w | DOI Listing |
Background: Liquid biopsy for Alzheimer's disease (AD) biomarkers in cerebral spinal fluid (CSF) or blood samples is becoming a significant sector in the management of AD and AD related dementia (ADRD). Whereas different types of molecules, such as small molecules, peptides, and antibodies, have been used as ligands for targeting AD biomarkers/pathologies such as amyloid beta peptides (Aβs), current liquid biopsy approaches mostly use antibodies. However, the activity and affinity of the antibodies can vary depending on the source and preparation as well as the stability in storage.
View Article and Find Full Text PDFBackground: XPro1595 (XPro) is a brain-penetrant, recombinant protein variant of human tumor necrosis factor (TNF) rationally designed to selectively neutralize only the soluble, pro-inflammatory form of the cytokine (solTNF). An unbiased proteomic analysis of CSF samples from an open-label, phase-1b study (NCT03943264) in patients with Alzheimer's disease (AD) was conducted to assess for pharmacodynamic activity and disease-specific target engagement.
Method: Patients with AD (n = 20) were treated for 12-weeks with one of three doses of XPro: 0.
Background: Polyunsaturated fatty acids are metabolized by cytochrome P450 (CYP450) into anti-inflammatory, pro-resolving epoxides, which are rapidly converted to inactive and cytotoxic diols by soluble epoxide hydrolase (sEH). Increased CYP450-sEH metabolites are associated with worse cognition in type 2 diabetes mellitus (T2DM), and greater white matter hyperintensities (WMH) in patients with stroke. We examined whether the relationship between linoleic acid (LA)-derived CYP450-sEH metabolites (oxylipins) and small vessel disease (SVD) markers differ across diabetes status.
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January 2025
Department of Physics and Materials Science, University of Luxembourg, Esch-sur-Alzette, L-4365, Luxembourg.
Cu(In, Ga)S demonstrates potential as a top cell material for tandem solar cells. However, achieving high efficiencies has been impeded by open-circuit voltage (V) deficits arising from In-rich and Ga-rich composition segregation in the absorber layer. This study presents a significant improvement in the optoelectronic quality of Cu(In, Ga)S films through the mitigation of composition segregation in three-stage co-evaporated films.
View Article and Find Full Text PDFNat Commun
January 2025
Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Dr., Gaithersburg, MD, USA.
The sex chromosomes contain complex, important genes impacting medical phenotypes, but differ from the autosomes in their ploidy and large repetitive regions. To enable technology developers along with research and clinical laboratories to evaluate variant detection on male sex chromosomes X and Y, we create a small variant benchmark set with 111,725 variants for the Genome in a Bottle HG002 reference material. We develop an active evaluation approach to demonstrate the benchmark set reliably identifies errors in challenging genomic regions and across short and long read callsets.
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