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hong, y.

Publications and source records attributed to hong, y..

4 recordsLinked to original sources

Protein inverse folding through joint modeling of surface and backbone geometry

Inverse protein folding aims to generate amino acid sequences compatible with a given protein structure. While recent deep learning methods have achieved strong performance by conditioning on residue-level backbone geometry, backbone-only representations insufficiently constrain surface-exposed residues and thus incompletely capture the structural determinants of sequence identity. Here we propose Surleton, a structure-aware inverse folding framework that jointly models backbone geometry and protein surface organization. By integrating complementary surface geometric information, Surleton refines the conditional sequence distribution and improves the balance of sequence modeling across buried and exposed residues. On the CATH4.2 and SCOPe benchmarks, Surleton consistently outperforms backbone-only baselines in sequence recovery, sequence similarity, and predictive confidence, with especially strong improvements on surface-exposed residues. Together, these findings indicate that protein surface geometry serves as a complementary source of structural constraint and that surface-aware modeling may provide a promising direction for improving inverse protein folding.

bioinformatics↗

NMDA receptor-dependent presynaptic homeostatic plasticity?

Excitatory glutamatergic synapses in the brain are remarkably plastic. Two forms of plasticity have received the most attention: long-term potentiation (LTP) and synaptic homeostasis. While LTP requires the activation of NMDA receptors, synaptic homeostasis does not. However, both phenomena are mediated by the recruitment of postsynaptic AMPA receptors to the synapses. Recently a new form of plasticity has been described referred to as presynaptic homeostatic plasticity (PHP) (Chipman et al., 2022; Chipman et al., 2025). Pharmacological inhibition of AMPA synaptic responses in CA1 hippocampal pyramidal cells initiates a rapid homeostatic response that results in the recovery of the AMPA responses to normal values in the continued presence of the inhibitor. Accompanying this recovery is a doubling of the NMDA response which is interpreted as an increase in the release of glutamate. This is provocative since it is the first report claiming that a reduction in AMPA responses triggers an enhancement in NMDA responses. Using three different protocols to monitor synaptic responses we fail to observe any recovery of synaptic responses in the presence of an AMPA inhibitor. Furthermore, there was no enhancement in NMDA responses. Thus, we find no evidence for the presence of PHP at CA1 hippocampal synapses.

neuroscience↗

Detection of Multiple Types of Cancer Driver Mutations Us-ing Targeted RNA Sequencing in NSCLC

Currently, DNA and RNA are used separately to capture different types of gene mutations. DNA is commonly used for the detection of SNVs, indels and CNVs; RNA is used for analysis of gene fusion and gene expression. To perform both DNA sequencing (DNA-seq) and RNA-seq, material is divided into two copies, and two different procedures are required for sequencing. Due to overconsumption of samples and experimental process complexity, it is necessary to create an experimental method capable of analyzing SNVs, indels, fusions and expression. We developed an RNA-based hybridization capture panel targeting actionable driver oncogenes in solid tumors and corresponding sample preparation and bioinformatics workflows. Analytical validation with an RNA standard reference containing 16 known fusion mutations and 6 SNV mutations demonstrated a detection specificity of 100.0% [95% CI 88.7%~100.0%] for SNVs and 100.0% [95% CI 95.4%~100.0%] for fusions. The targeted RNA panel achieved a 0.73-2.63 copies/ng RNA lower limit of detection (LOD) for SNVs and 0.21-6.48 copies/ng RNA for fusions. Gene expression analysis revealed a correlation greater than 0.9 across all 15 cancer-related genes between the RNA-seq results and targeted RNA panel. Among 1253 NSCLC FFPE tumor samples, multiple mutation types were called from DNA- and RNA-seq data and compared between the two assays. The DNA panel detected 103 fusions and 21 METex14 skipping events; 124 fusions and 26 METex14 skipping events were detected by the target RNA panel; 21 fusions and 4 METex14 skipping events were only detected by the target RNA panel. Among the 173 NSCLC samples negative for targetable mutations by DNA-seq, 15 (15/173, 8.67%) showed targetable gene fusions that may change clinical decisions with RNA-seq. In total, 226 tier I and tier II missense variants for NSCLC were analyzed at genomic (DNA-seq) and transcriptomic (RNA-seq) levels. The positive percent agreement (PPA) was 97.8%, and the positive predictive value (PPV) was 98.6%. Interestingly, variant allele frequencies were generally higher at the RNA level than at the DNA level, suggesting relatively dominant expression of mutant alleles. PPA was 97.6% and PPV 99.38% for EGFR 19del and 20ins variants. We also explored the relationship of RNA expression with gene copy number and protein expression. The RPKM of EGFR transcripts assessed by the RNA panel showed a linear relationship with copy number quantified by the DNA panel, with an R of 0.8 in 1253 samples. In contrast, MET gene expression is regulated in a more complex manner. In IHC analysis, all 3+ samples exhibited higher RPKM levels; IHC level of 2+ and below showed lower RNA expression. Parallel DNA- and RNA-seq and systematic analysis demonstrated the accuracy and robustness of the RNA sequencing panel in identifying multiple types of variants for cancer therapy. Contact: zhaojia0327@126.com

molecular biology↗

An atlas of infiltrated B-lymphocytes in breast cancer revealed by paired single-cell RNA-sequencing and antigen receptor profiling

While it has been well-recognized that T-cell mediated adaptive cellular immunity plays important roles in cancer immune response and tumor control, the roles of B lymphocytes in tumor development and therapy have only been proposed until recently, and are still mostly controversial. To gain mechanistic insights into the origin and dynamics of tumor infiltrated immune cells, especially B lymphocytes, we combine single-cell RNA-sequencing and antigen receptor lineage analysis to characterize a large number of triple-negative breast cancer (TNBC) infiltrated immune cells and present a comprehensive atlas of infiltrated B-lymphocytes in TNBC, the most aggressive breast cancer subtype. We demonstrate that TNBC infiltrated B cells showed more mature and memory B cell characteristics, as well as high clonality and extensive IgH class switching recombination and somatic hypermutations. The B cell signatures based on single-cell RNA-seq results are significantly associated with improved survival for TNBC patients and provide better prognostication than classic single B cell markers (CD19 or CD20). Further dissection of the mechanisms regulating the functions and dynamic distribution of tumor infiltrated B cell populations will provide new clues for tumor immunotherapy.

immunology↗