Publications by authors named "Cheng-Han Yang"

Recent reports highlight the efficacy of engineered mycobacteriophages to treat non-tuberculosis mycobacterial disease. Molecular insights into mycobacteriophage architecture and host interactions could allow structure-guided phage engineering to increase efficacy and broaden host range, but such information is currently unavailable. We describe the cryoelectron microscopy (cryo-EM) structure of mycobacteriophage Douge, which contains 1,105 protein subunits assembled into a complete siphophage and is coated with glycan-binding domains for mycobacterial cell surface interactions.

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Animal-like cryptochromes are photoreceptors that control circadian rhythm and signaling in many eukaryotes. Transient photoreduction of the cryptochrome flavin chromophore initiated signaling via a poorly understood mechanism. By serial femtosecond crystallography (SFX), we show that the photoreduction mechanism of cryptochrome involves three loci [carboxyl-terminal region, a transient protonation pathway, and flavin adenine dinucleotide (FAD)-binding site] acting in unison to accomplish three effects: radical pair stabilization, protonation of FAD radical, and formation of the signaling state.

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The coronavirus disease 2019 pandemic presented unprecedented challenges in balancing infection control measures with the timely management of ST-segment elevation myocardial infarction (STEMI), a time-sensitive condition. This study investigates the pandemic's effects on STEMI management times and outcomes at a high-volume medical center in Taiwan. A retrospective analysis of 1309 STEMI patients was conducted at Chang Gung Memorial Hospital between 2017 and 2022.

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Untranslated regions (UTRs) contain crucial regulatory elements for RNA stability, translation and localization, so their integrity is indispensable for gene expression. Approximately 3.7% of genetic variants associated with diseases occur in UTRs, yet a comprehensive understanding of UTR variant functions remains limited due to inefficient experimental and computational assessment methods.

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Background: The rate of survival after out-of-hospital cardiac arrest varies depending on the timeliness and effectiveness of prehospital interventions. This study was conducted to compare out-of-hospital cardiac arrest outcomes between intravenous and intraosseous routes and between upper and lower extremity routes for drug administration.

Methods And Results: We retrospectively analyzed data (collected using the Utstein template) from 1220 patients who had experienced out-of-hospital cardiac arrest in Taiwan's Taoyuan City between January 2021 and August 2023.

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Article Synopsis
  • - The study addresses the limitations of traditional mass spectrometry (MS) for intact protein analysis, particularly due to large protein sizes and slow ion flight speeds which lead to low sensitivity and resolution.
  • - A new compact ion trap-mass spectrometry method is proposed to enhance the detection of protein ions, utilizing a specially designed radio frequency waveform to minimize ion motion disturbances and improve spectral quality.
  • - This method successfully measured cytochrome C proteins with a resolution of 20 Da and demonstrated quick scanning capabilities for other proteins, showcasing its potential for high-resolution protein analysis.
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Eukaryotic ribosomal proteins contain extended regions essential for translation coordination. Dedicated chaperones stabilize the associated ribosomal proteins. We identified Bcp1 as the chaperone of uL14 in Saccharomyces cerevisiae.

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The rise of cutting-edge precision cancer treatments has led to a growing significance of the optimal biological dose (OBD) in modern oncology trials. These trials now prioritize the consideration of both toxicity and efficacy simultaneously when determining the most desirable dosage for treatment. Traditional approaches in early-phase oncology trials have conventionally relied on the assumption of a monotone relationship between treatment efficacy and dosage.

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The theories for substrate recognition in enzyme catalysis have evolved from lock-key to induced fit, then conformational selection, and conformational selection followed by induced fit. However, the prevalence and consensus of these theories require further examination. Here we use cryogenic electron microscopy and African swine fever virus type 2 topoisomerase (AsfvTop2) to demonstrate substrate binding theories in a joint and ordered manner: catalytic selection by the enzyme, conformational selection by the substrates, then induced fit.

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The Bayesian logistic regression method (BLRM) is a widely adopted and flexible design for finding the maximum tolerated dose in oncology phase I studies. However, the BLRM design has been criticized in the literature for being overly conservative due to the use of the overdose control rule. Recently, a discussion paper titled "Improving the performance of Bayesian logistic regression model with overall control in oncology dose-finding studies" in Statistics in Medicine has proposed an overall control rule to address the "excessive conservativeness" of the standard BLRM design.

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Article Synopsis
  • Phycobilisomes (PBS) are complex structures that help transfer light energy in photosynthesis, and they evolved over time into a specific shape with peripheral rods.
  • Researchers studied a primitive "paddle-shaped" PBS from a thylakoid-free cyanobacterium to better understand the ancestral characteristics of these complexes.
  • The findings suggest that while the paddle-shaped PBS is less efficient than more advanced forms, it may have played a role in increasing light absorption before the development of more complex thylakoid structures.
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Photolyases, a ubiquitous class of flavoproteins, use blue light to repair DNA photolesions. In this work, we determined the structural mechanism of the photolyase-catalyzed repair of a cyclobutane pyrimidine dimer (CPD) lesion using time-resolved serial femtosecond crystallography (TR-SFX). We obtained 18 snapshots that show time-dependent changes in four reaction loci.

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The structure determination of protein tyrosine phosphatase (PTP): phospho-protein complexes, which is essential to understand how specificity is achieved at the amino acid level, remains a significant challenge for protein crystallography and cryoEM due to the transient nature of binding interactions. Using rPTPεD1 and phospho-SrcKD as a model system, we have established an integrative workflow to address this problem, by means of which we generate a protein:phospho-protein complex model using predetermined protein structures, SAXS and pTyr-tailored MD simulations. Our model reveals transient protein-protein interactions between rPTPεD1 and phospho-SrcKD and is supported by three independent experimental validations.

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Article Synopsis
  • Regulation of CO fixation in cyanobacteria is crucial for both the organism's survival and the global carbon cycle.
  • A distinct ATP-sensing mechanism in the enzyme phosphoketolase (SeXPK) allows it to redirect carbon flow away from the Calvin-Benson-Bassham cycle when ATP levels decrease.
  • Deleting the SeXPK gene significantly boosts carbon fixation, especially during transitions from light to dark, and can lead to unexpected sucrose secretion, highlighting its regulatory importance across various life forms.
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Background: Perineural invasion (PNI), a form of local invasion defined as the ability of cancer cells to invade in, around, and through nerves, has a negative prognostic impact in oral cavity squamous cell carcinoma (OCSCC). Unfortunately, the diagnosis of PNI suffers from a significant degree of intra- and interobserver variability. The aim of this pilot study was to develop a deep learning-based human-enhanced tool, termed domain knowledge enhanced yield (Domain-KEY) algorithm, for identifying PNI in digital slides.

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Purpose: Solitary type primary intracranial malignant melanoma (PIMM) is extremely rare but fatal. The optimal treatment algorithm according to clinical relevance of symptoms and outcomes is unclear. This series emphasized the prognostic factors of solitary PIMM and established the treatment algorithm for this rare disease.

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Flavin coenzymes are universally found in biological redox reactions. DNA photolyases, with their flavin chromophore (FAD), utilize blue light for DNA repair and photoreduction. The latter process involves two single-electron transfers to FAD with an intermittent protonation step to prime the enzyme active for DNA repair.

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Background: Interferon-induced protein with tetratricopeptide repeat 2 (IFIT2) is a reported metastasis suppressor in oral squamous cell carcinoma (OSCC). Metastases and cachexia may coexist. The effect of cancer metastasis on cancer cachexia is largely unknown.

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Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity with poor prognosis. The dysregulation of Notch signaling pathway has been implicated in the OSCC tumorigenesis. However, the clinical implication of NOTCH1 mutation status in OSCC remains unelucidated.

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Due to the increasing incidence of malignant gliomas, particularly glioblastoma multiforme (GBM), a simple and reliable GBM diagnosis is needed to screen early the death-threaten patients. This study aimed to identify a protein that can be used to discriminate GBM from low-grade astrocytoma and elucidate further that it has a functional role during malignant glioma progressions. To identify proteins that display low or no expression in low-grade astrocytoma but elevated levels in GBM, glycoprotein fibronectin (FN) was particularly examined according to the mining of the Human Protein Atlas.

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Background: The tongue has been identified as a high-risk site for malignant transformation of oral leukoplakia. The purpose of this study was to investigate the clinicopathological characteristics and treatment outcomes of the dorsal and ventrolateral tongue leukoplakia.

Methods: Demographic data and pathological results of patients who underwent carbon dioxide laser surgery for tongue leukoplakia from 2002 to 2019 were retrospectively reviewed and analyzed statistically.

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Both high-fidelity and mismatch-tolerant recombination, catalyzed by RAD51 and DMC1 recombinases, respectively, are indispensable for genomic integrity. Here, we use cryo-EM, MD simulation and functional analysis to elucidate the structural basis for the mismatch tolerance of DMC1. Structural analysis of DMC1 presynaptic and postsynaptic complexes suggested that the lineage-specific Loop 1 Gln244 (Met243 in RAD51) may help stabilize DNA backbone, whereas Loop 2 Pro274 and Gly275 (Val273/Asp274 in RAD51) may provide an open "triplet gate" for mismatch tolerance.

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