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Biology subjects

Fagherazzi, P.

Publications and source records attributed to Fagherazzi, P..

2 recordsLinked to original sources

Quantitative AI-based DNA fiber workflow to study replication stress

Replication stress (RS) is a prominent source of genome instability and human diseases. Understanding its molecular mechanism through various quantitative and unbiased methodologies is essential for the advancement of treatment strategies. One of the powerful methods to study DNA replication dynamics and its alterations at the single-molecule resolution is the DNA fiber assay. However, this method relies exclusively on manual image acquisition and analysis, making it time-consuming and susceptible to user bias. Here, we present a quantitative AI-based DNA fiber (qAID) workflow enabling imaging and multiparameter analysis of thousands of DNA fibers within several dozen minutes. Our workflow quantifies key parameters, including DNA fiber frequency, length, and symmetry, while also allowing visual inspection of individual DNA fibers using unbiased image galleries. The robustness of the workflow is demonstrated by comprehensive datasets of biologically relevant experiments performed by three independent laboratories. Overall, qAID workflow provides a fast and effective examination of replication dynamics and its alterations at the single-molecule resolution.

cell biology↗

Development of a cell-permeable Biotin-HaloTag ligand to explore functional differences between protein variants across cellular generations

HaloTag technology represents a versatile tool for studying proteins. Fluorescent HaloTag ligands employed in sequential labeling led to the discovery of distinct protein variants for histones, cohesins, and MCM complexes. Nonetheless, an efficient biochemical approach to separate the distinct protein variants to study their biological functions is missing. Principally being a gap in technology, the HaloTag toolbox lacks affinity ligands displaying good cell permeability and efficient affinity capture. Here, we describe the design, synthesis, and validation of a new cell-permeable Biotin-HaloTag ligand, which allows rapid labeling of Halo-tagged proteins in live cells and their efficient separation using streptavidin pull-down. Our work outlines how to use the herein-developed affinity ligand in sequential labeling to biochemically separate distinct protein variants and study their biological properties. The approach holds immense potential for addressing fundamental questions concerning essential cellular processes, including genome duplication and chromatin maintenance.

cell biology↗