Biomolecular condensates (BCs) are membraneless hubs enriched in proteins and nucleic acids that have become important players in many cellular functions. Uncovering the sequence determinants of proteins for phase separation is important in understanding the biophysical and biochemical properties of BCs. Despite significant discoveries in the last decade, the role of cysteine residues in BC formation and dissolution has remained unknown. Here, to determine the involvement of disulfide crosslinks and their redox sensitivity in BCs, we designed a 'stickers and spacers' model of phase-separating peptides interspersed with cysteines. Through biophysical investigations, we learned that cysteines promote liquid-liquid phase separation in oxidizing conditions and perpetuate liquid condensates through disulfide crosslinks, which can be reversibly tuned with redox chemistry. By varying the composition of cysteines, subtle but distinct changes in the viscoelastic behavior of the condensates were observed. Empirically, we conclude that cysteines are neither stickers nor spacers but function as covalent nodes to lower the effective concentrations for sticker interactions and inhibit system-spanning percolation networks. Together, we unmask the role of cysteines in protein phase behavior and the potential to develop tunable, redox-sensitive viscoelastic materials.
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http://dx.doi.org/10.1101/2024.07.13.603402 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
Maintaining human body temperature in both high and low-temperature environments is fundamental to human survival, necessitating high-performance thermal insulation materials to prevent heat exchange with the external environment. Currently, most fibrous thermal insulation materials are characterized by large weight, suboptimal thermal insulation, and inferior mechanical and waterproof performance, thereby limiting their effectiveness in providing thermal protection for the human body. In this study, lightweight, waterproof, mechanically robust, and thermal insulating polyamide-imide (PAI) grooved micro/nanofibrous aerogels were efficiently and directly assembled by electrospinning.
View Article and Find Full Text PDFSci Adv
January 2025
Key Laboratory of Plant Carbon Capture, Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Plants sense and respond to hyperosmotic stress via quick activation of sucrose nonfermenting 1-related protein kinase 2 (SnRK2). Under unstressed conditions, the protein phosphatase type 2C (PP2C) in clade A interact with and inhibit SnRK2s in subgroup III, which are released from the PP2C inhibition via pyrabactin resistance 1-like (PYL) abscisic acid receptors. However, how SnRK2s are released under osmotic stress is unclear.
View Article and Find Full Text PDFCancer Res
January 2025
Yale University, New Haven, CT, United States.
Biomolecular condensation has emerged as a general principle in organizing biological processes, including immune response. Xu and colleagues recently reported that the cytoplasmic tail of the CD3ɛ subunit of TCR complex, when fused to CAR, can promote CAR condensation by liquid-liquid phase separation. Through sequence engineering, the authors identified modified CD3ɛ sequences that enhance the maturation of the immunological synapse and co-receptor signaling, leading to an improvement of cytotoxicity in vitro and anti-tumor effects in mouse xenograft models.
View Article and Find Full Text PDFInorg Chem
January 2025
Beijing Spacecrafts Manufacturing Factory, Beijing 100094, P. R. China.
The rapid upsurge of metal-organic frameworks (MOFs) has sparked profound interest in their potential as proton conductors for proton exchange membrane fuel cells. However, proton-conducting behaviors of hydrophobic MOFs remain poorly understood compared with their hydrophilic counterparts, largely due to the absence of a microscopic phase separation structure akin to that found in Nafion membranes. Herein, we demonstrate a strategy for regulating the structures and proton conductivities of MOFs by separately incorporating hydrophobic -C(CF)- group alongside hydrophilic -O- and -SO- groups into organic ligands as linkers.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Hydrogen and Renewable Energy, Kyungpook National University, Daegu 41566, Republic of Korea.
The side-chain directions in nonfullerene acceptors (NFAs) strongly influence the intermolecular interactions in NFAs; however, the influence of these side chains on the morphologies and charge carrier dynamics of Y6-based acceptors remains underexplored. In this study, we synthesize four distinct Y6-based acceptors, i.e.
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