Although DNA methylation primarily represses TEs, it also represses select genes that are methylated in plant body tissues but demethylated by DNA glycosylases (DNGs) in endosperm or pollen. Activity of either one of two DNGs, MDR1 or DNG102, is essential for pollen viability in maize. Using single-pollen mRNA sequencing on pollen segregating mutations in both genes, we identified 58 candidate DNG target genes that account for 11.1% of the wild-type transcriptome but are silent or barely detectable in the plant body (sporophyte). They are unusual in their tendency to lack introns but even more so in their having TE-like methylation in their CDS. The majority have predicted functions in cell wall modification, and they likely support the rapid tip growth characteristic of pollen tubes. These results suggest a critical role for DNA methylation and demethylation in regulating maize genes with potential for extremely high expression in pollen but constitutive silencing elsewhere.
8-oxoguanine (8-oxoG) is a common oxidative DNA lesion that causes G > T substitutions. Determinants of local and regional differences in 8-oxoG-induced mutability across genomes are currently unknown. Here, we show DNA oxidation induces G > T substitutions and insertion/deletion (INDEL) mutations in human cells and cancers.
Base excision repair (BER) is an essential cellular mechanism that repairs small, non-helix-distorting base lesions in DNA, resulting from oxidative damage, alkylation, deamination, or hydrolysis. This review highlights recent advances in understanding the molecular mechanisms of BER enzymes through single-molecule studies. We discuss the roles of DNA glycosylases in lesion recognition and excision, with a focus on facilitated diffusion mechanisms such as sliding and hopping that enable efficient genome scanning.
Background: The efficacy of tyrosine kinase inhibitors (TKIs) targeting the EGFR is limited due to the persistence of drug-tolerant cell populations, leading to therapy resistance. Non-genetic mechanisms, such as metabolic rewiring, play a significant role in driving lung cancer cells into the drug-tolerant state, allowing them to persist under continuous drug treatment.
Methods: Our study employed a comprehensive approach to examine the impact of the glycolytic regulator 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB3) on the adaptivity of lung cancer cells to EGFR TKI therapies.
Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, 7491, Trondheim, Norway; Department of Neurology and Clinical Neurophysiology, University Hospital of Trondheim, 7006, Trondheim, Norway. Electronic address:
8-oxo-7,8-dihydroguanine (OG) is one of the most abundant oxidative lesions in the genome and is associated with genome instability. Its mutagenic potential is counteracted by a concerted action of 8-oxoguanine DNA glycosylase (OGG1) and mutY homolog DNA glycosylase (MUTYH). It has been suggested that OG and its repair has epigenetic-like properties and mediates transcription, but genome-wide evidence of this interdependence is lacking.
Human 8-oxoguanine DNA -glycosylase 1 (hOGG1) is an essential enzyme in DNA repair, responsible for recognizing and excising 8-oxoguanine (8OG), the lesion resulting from oxidative damage to guanine (G). By removing 8OG, hOGG1 prevents mutations like G-to-T transversions, maintains genomic stability, and reduces the risk of cancer and other diseases. Structural studies of hOGG1 bound to DNA have shown that lesion recognition occurs through base eversion from the DNA helix and hOGG1 finger residue insertion into the DNA helix.
