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Biology subjects

Lu, W.-T.

Publications and source records attributed to Lu, W.-T..

3 recordsLinked to original sources

A Unified and Interpretable Framework for Evaluating Fluorescence Trace Quality in Transcription Kinetics

Quantifying transcriptional dynamics from fluorescence traces is a powerful approach to understanding gene regulation, but such analysis critically depends on the quality of the fluorescence signal. Experimental researchers often lack an objective and computationally simple way to assess trace quality before kinetic modeling. In this study, we fill in this gap via systematically investigating two key factors (i.e., signal-to-noise ratio (SNR) and trace length) using synthetic data generated from a composite-state Hidden Markov Model (cpHMM) simulator. By analyzing thousands of simulated traces, we identified quantitative thresholds (SNR [≥] 30 dB and length [≥] 360) beyond which transcriptional dynamics can be reliably captured for kinetic inference. Building on these findings, we further discovered a unified and easily computable quality indicator based on the difference between the first two autocorrelation lags. A threshold value of approximately 0.07 effectively separates reliable from low quality traces, providing a simple yet robust criterion for data selection. Together, these results establish a practical framework for assessing fluorescence trace reliability, offering experimental researchers an interpretable and computationally efficient tool to ensure data quality prior to transcription kinetics modeling.

bioinformatics↗

DDX17 is required for efficient DSB repair at DNA:RNA hybrid deficient loci

Proteins with RNA-binding activity are increasingly being implicated in DNA damage responses (DDR). Additionally, DNA:RNA-hybrids are rapidly generated around DNA double-strand breaks (DSBs), and are essential for effective repair. Here, using a meta-analysis of proteomic data, we identify novel DNA repair proteins and characterise a novel role for DDX17 in DNA repair. We found DDX17 to be required for both cell survival and DNA repair in response to numerous agents that induce DSBs. Analysis of DSB repair factor recruitment to damage sites suggested a role for DDX17 early in the DSB ubiquitin cascade. Genome-wide mapping of R-loops revealed that while DDX17 promotes the formation of DNA:RNA-hybrids around DSB sites, this role is specific to loci that are naturally deficient for DNA:RNA-hybrids. We propose that DDX17 facilitates DSB repair at loci that are inefficient at forming DNA:RNA-hybrids by catalysing the formation of DSB-induced hybrids, thereby allowing propagation of the damage response.

cell biology↗

An anti-CRISPR protein induces strong non-specific DNA binding activity in a CRISPR-Cas complex

Phages and other mobile genetic elements express anti-CRISPR proteins (Acrs) to protect their genomes from destruction by CRISPR-Cas systems. Acrs usually block the ability of CRISPR-Cas systems to bind or cleave their nucleic acid substrates. Here, we investigate an unusual Acr, AcrIF9, that induces a gain-of-function to a type I-F CRISPR-Cas (Csy) complex, causing it to bind strongly to DNA that lacks both a PAM sequence and sequence complementarity. We show that specific and non-specific dsDNA compete for the same site on the Csy:AcrIF9 complex with rapid exchange, but specific ssDNA appears to still bind through complemetarity to the CRISPR RNA. We also demonstrate that induction of non-specific DNA-binding is a conserved property of diverse AcrIF9 homologues, implying that this activity contributes the biologically relevant function of this Acr family. AcrIF9 provides another example of the surprising variety of mechanisms by which Acrs inhibit CRISPR-Cas systems.

microbiology↗