Biology subjects

Park, H. L.

Publications and source records attributed to Park, H. L..

4 recordsLinked to original sources

bioRxiv2025

UC Irvine Brain Initiative Cell Atlas Network (BICAN) Brain Procurement Program for the Center for Multiomic Human Brain Cell Atlas Project

High-quality neurotypical postmortem human brain tissue is essential but difficult to obtain for constructing comprehensive human brain cell atlases. Here we describe the establishment of UC Irvines Brain Procurement Program, a coordinated initiative to collect and process neurotypical donor brains for multiomic mapping studies within the NIH BRAIN Initiative Cell Atlas Network (BICAN) consortium. Through partnerships with the Orange County Coroners Office, the UC Irvine Willed Body Program, UCI Medical Center, and the Childrens Hospital of Orange County, we have developed standardized workflows encompassing donor identification, postmortem brain recovery and processing, region-of-interest dissection, neurotypical donor selection, and data management. Our experience demonstrates the feasibility of a community-based, multi-institutional procurement framework while highlighting challenges in recruiting neurotypical donors and ensuring demographic representation reflective of Southern California. We further identify opportunities to strengthen outreach and donation pathways. This program provides a scalable model for advancing population-reflective, high-quality human brain cell atlas efforts. HighlightsO_LIEstablish a multi-site pipeline for procuring high-quality neurotypical human brains. C_LIO_LIDemonstrate feasibility of donor collection across childhood to adulthood. C_LIO_LIIdentify barriers and propose strategies to improve broad donor recruitment. C_LI

neuroscience↗

bioRxiv2025

Rapid ethylene-triggered protein complex remodeling in dark grown hypocotyls

Protein-level cellular dynamics, including multimerization, play a crucial role in rapid adaptation of plants during developmental transitions and environmental stresses. The gaseous hormone ethylene is a key regulator of rapid cellular growth modulation. During soil emergence, etiolated seedlings undergo crucial morphological changes to their apical hooks and hypocotyls, with ethylene inhibiting hypocotyl axial elongation while promoting radial expansion. Ethylene triggers these growth responses within two hours; however, the protein machineries and cellular processes that mediate morphogenesis control are not known. Here, we used quantitative proteomics and co-fractionation mass spectrometry to test for rapid ethylene-dependent changes in protein abundance and protein complex composition. Protein multimerization responses were numerous and diverse. There were instances of protein complex assembly and disassembly, with varying degrees of completeness. Small-scale validation tests indicate that the identified proteins play a role in hypocotyl development and suggest that this novel approach to gene discovery identifies potential targets for ethylene-mediated growth regulation and enhanced seedling adaptability during early development.

plant biology↗

bioRxiv2024

Autophagy-mediated CTR1 turnover orchestrates the reciprocal interaction between autophagy and ethylene signaling

The phytohormone ethylene and autophagy are crucial for plant adaptation to various environmental stresses, yet the integration of these signaling networks into stress responses is not fully understood. Here, we report that ethylene signaling and autophagy reciprocally regulate each other through Constitutive Triple Response 1 (CTR1), a negative regulator of ethylene signaling. Autophagy facilitates the turnover of the CTR1 protein, which interacts with the key autophagy-related protein ATG8 as autophagic cargo. Impaired autophagy attenuates ethylene responses. Conversely, ethylene-insensitive mutants exhibit enhanced autophagic flux, while a constitutive ethylene response mutant is hypersensitive to carbon starvation stress, which induces autophagy. This suggests that ethylene suppresses autophagy during carbon limitation. We further elucidated that ethylene receptors with a receiver domain play a primary role in modulating autophagy, while receptor kinase activity is not essential. Our findings uncover that the autophagic control of CTR1 degradation allows reciprocal cross-regulation between autophagy and ethylene transduction cascades, optimizing stress responses and resilience.

plant biology↗

bioRxiv2020

Ethylene-triggered subcellular trafficking of CTR1 suppresses the response to ethylene gas

Ethylene gas controls plant growth and stress responses. Ethylene-exposed dark-grown seedlings exhibit dramatic growth reduction, yet the seedlings rapidly return to the basal growth rate when ethylene gas is removed. However, the underlying mechanism governing this reversible acclimation of dark-grown seedlings to ethylene remains enigmatic. Here, we report that ethylene triggers the translocation of the Raf-like protein kinase CONSTITUTIVE TRIPLE RESPONSE1 (CTR1), a negative regulator of ethylene signaling, from the endoplasmic reticulum to the nucleus. Nuclear-localized CTR1 stabilizes the ETHYLENE-INSENSITIVE3 (EIN3) transcription factor via interaction with the EIN3-BINDING F-box (EBF) proteins, thus enhancing the ethylene response and delaying growth recovery. These findings uncover a mechanism of the ethylene signaling pathway that links the spatiotemporal dynamics of cellular signaling components to organismal responses.

plant biology↗