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Biology subjects

Hardy, W. R.

Publications and source records attributed to Hardy, W. R..

3 recordsLinked to original sources

Spatiotemporal remodeling of cytoskeletal and junction networks during somatic cell reprogramming

Summary/AbstractReprogramming somatic cells into induced pluripotent stem cells involves a dramatic reorganization of the cytoskeleton and junctions during the critical mesenchymal-to-epithelial transition stage. While protein abundance changes have been profiled, the spatiotemporal dynamics of protein-protein associations involving these structural components remain poorly resolved. Here, we present a time-resolved proximity proteomics resource that maps cytoskeletal and junctional remodeling across 27 baits during the early stages of reprogramming. We identified over 1100 high-confidence interactions, including many not previously reported, capturing the dynamic reorganization of cell architecture. By integrating proximity-dependent biotinylation with quantitative proteomics, we distinguished spatial relocalizations from abundance-driven effects. Dynamic redistributions of actin regulators and desmosomal proteins were observed, and a targeted short interfering RNA screen uncovered early acting structural proteins essential for colony formation. Our findings reveal adhesion and cytoskeletal maturation as structural bottlenecks in reprogramming and provide a broadly applicable framework for mapping subcellular remodeling during dynamic cell fate transitions.

systems biology↗

Benchmarking of proximity-dependent biotinylation enzymes across cellular compartments and time windows

Proximity-dependent biotinylation has become a powerful approach for mapping protein interactions and subcellular organization in living cells. Although a growing number of engineered biotin ligases have been introduced, their performance has not been systematically evaluated across diverse cellular contexts. Here, we benchmark ten proximity ligases spanning three bacterial lineages using standardized proteomic workflows across multiple labeling durations, subcellular compartments, and two human cell types. While all enzymes efficiently detect proximal associations, they differ in labeling kinetics, background activity, and spatial specificity. TurboID exhibits the highest overall activity but generates substantial background in standard media. miniTurbo and ultraID support rapid, biotin-dependent labeling with low background, making them better suited for dynamic and time-resolved applications. However, miniTurbo showed aberrant mitochondrial localization with two cytoskeletal baits (VASP and PFN1). Across 15 diverse baits, ultraID consistently provides an excellent combination of specificity, efficiency, and spatial compatibility--including unique recovery of Golgi-resident glycosyltransferases. This study serves as a comparative resource, offering guidance for enzyme selection and experimental design in proximity proteomics.

systems biology↗

SHC-3: a previously unidentified C. elegans Shc family member functions in the insulin-like signaling pathway to enhance survival during L1 arrest

Shc proteins function in many different signaling pathways where they mediate phosphorylation-dependent protein-protein interactions. These proteins are characterized by the presence of two phosphotyrosine-binding domains, an N-terminal PTB and a C-terminal SH2. We describe a previously unrecognized C. elegans Shc gene, shc-3 and characterize its role of in stress response. Both shc-3 and shc-1 are required for long-term survival in L1 arrest, however, they do not act redundantly but rather play distinct roles in this process. SHC-3 function in survival during L1 arrest is DAF-16-dependent, demonstrating that like SHC-1, SHC-3 functions in the Insulin-like signaling pathway. In the absence of SHC-3, nuclear entry and exit are slowed suggesting that SHC-3 is required for rapid changes in DAF-16 signaling.

genetics↗