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Biology subjects

Hong, J. C.

Publications and source records attributed to Hong, J. C..

4 recordsLinked to original sources

STRUCTURAL AND MOLECULAR DYNAMICS ANALYSIS OF HUMAN β-DEFENSIN 1 VARIANTS REVEALS DISTINCT PERTURBATION SIGNATURES

Human {beta}-defensin 1 (hBD-1) is a small, disulfide-constrained antimicrobial peptide produced predominantly in the kidney and urogenital tract, where it contributes to epithelial innate defense. Genetic variation in the gene encoding hBD-1 has been associated with altered expression levels and susceptibility to infections, including infection following solid organ transplantation, yet the molecular consequences of coding substitutions in the active, mature form remain largely undefined. Here, we integrate conventional genomics, protein bioinformatics, structural modeling, and molecular dynamics to investigate the molecular consequences of 93 human-observed hBD-1 missense variants. Evaluation of hBD-1 missense variants across sequence-, structure-, and dynamics-based dimensions reveals variant-specific molecular perturbation signatures that complement conventional and static biophysical predictions. By treating naturally occurring substitutions as a perturbation series across a compact defensin scaffold, this study identifies multiple molecular routes through which sequence variation can remodel an endogenous antimicrobial peptide and prioritizes variants for direct structure-function testing. These findings provide a mechanistic framework for investigating how naturally occurring hBD-1 variation may influence peptide behavior and, ultimately, antimicrobial function.

biophysics↗

A single-cell and spatial atlas of prostate cancer reveals the combinatorial nature of gene modules underlying lineage plasticity and metastasis

Prostate cancer encompasses a spectrum of disease states driven by complex cellular heterogeneity. To delineate the transcriptional programs underlying lineage plasticity and metastasis, we constructed a comprehensive single-cell atlas of 128 patients, spanning localized, castration-resistant, and metastatic disease. Lineage plasticity was prevalent in localized disease, with subsets of tumor cells adopting distinct basal-like and club-like states. Luminal-like cancer cells also displayed extensive lineage infidelity, defined not by a binary loss of identity but by the combinatorial erosion of luminal gene modules associated with higher grade and stage. In the metastatic setting, gene program association analysis (GPAS) identified a broad induction of cell-cycle gene modules across organ sites as well as an induction of organ-specific gene modules, including osteomimetic signaling in bone, neuro-migratory genes in brain, and erythroid-like transitions in liver. Neuroendocrine prostate cancers (NEPCs) were not monolithic but defined by combinations of NE-associated gene modules including a novel HES6 program. Notably, these modules were detected at intermediate levels in localized samples, suggesting molecular plasticity precedes histological transformation. We also developed a refined NE signature that could distinguish NEPC tumors more accurately than previously published signatures. Within the tumor microenvironment (TME), we observed an elevation of pro-inflammatory Th17 T-cells in African American patients and identified a rare Schwann cell population. Finally, we present PCformer, a transformer-based foundation model trained on >500,000 cells to automate cell-state classification. Together, this comprehensive atlas demonstrates the complex nature of gene modules underlying lineage infidelity and plasticity in cancer cells and highlights distinct immune and stromal populations within the tumor ecosystem.

genomics↗

A complex tissue-specific interplay between the Arabidopsis transcription factors AtMYB68, AtHB23, and AtPHL1 modulates primary and lateral root development and adaptation to salinity

O_LIAdaptation to soil is a well-regulated process vital for plant life. AtHB23 is a homeodomain-leucine zipper I transcription factor (TF), previously revealed as crucial for plant survival in front of salinity conditions. We wondered whether this TF has partners to achieve this essential function. C_LIO_LIA TF cDNA library screening, Y2H, BiFC, and CoIP assays were complemented with expression analyses and phenotypic characterizations of silenced, mutant, overexpressor, and crossed plants in normal and salinity conditions. C_LIO_LIWe revealed that AtHB23, AtPHL1, and AtMYB68 interact with each other, modulating root development and salinity response. The encoding genes coexpress in specific root tissues and developmental stages. In normal conditions, amiR68 silenced plants have less initiated roots, the opposite phenotype to that showed by amiR23 ones. AtMYB68 and AtPHL1 play contrary roles in lateral root elongation. Under salinity, where AtHB23 plays a crucial positive function, AtMYB68 cooperates with it, whereas AtPHL1 obstructs its action impacting survival ability and supporting the complex interaction between AtHB23, AtPHL1, and AtMYB68 in the primary and lateral roots. The root adaptation capability was associated with the amyloplast state. C_LIO_LIWe identified new molecular players that through a complex relationship determine Arabidopsis root architecture and survival ability in salinity conditions. C_LI

plant biology↗

The Arabidopsis ORA59 coordinates jasmonic acid- and ethylene-responsive gene expression to regulate plant immunity

Jasmonic acid (JA) and ethylene (ET) signaling modulate plant defense against necrotrophic pathogens. These hormone pathways lead to transcriptional reprogramming, which is a major part of plant immunity and requires the roles of transcription factors. ET response factors are responsible for the transcriptional regulation of JA/ET-responsive defense genes, among which ORA59 functions as a key regulator of this process and has been implicated in the JA-ET crosstalk. Here, we identified the ERELEE4 as an ORA59-binding cis-element, in addition to the well-characterized GCC box, demonstrating that ORA59 regulates JA/ET-responsive genes through direct binding to these elements in the gene promoters. Notably, ORA59 exhibited differential preference for the GCC box and ERELEE4, depending on whether ORA59 activation is achieved by JA and ET, respectively. Our results provide insights into how ORA59 can generate specific patterns of gene expression dynamics through JA and ET hormone pathways.

plant biology↗