Protein-folding stress is characteristic of specialized secretory cells and plays a dominant role in a multitude of diseases. The unfolded protein response (UPR) thus triggered is a proteostatic signaling network that adapts the protein-folding capacity of the endoplasmic reticulum to the cellular demands. We have measured the binding affinities between human GRP78, an essential chaperone located in ER, and two transmembrane UPR sensors (human PERK and Ire1α), with or without the addition of an unfolded protein client. We reveal distinct binding affinities between the binary and ternary complexes thus formed, that suggest a preference for the PERK signaling branch under stress, and a predilection for the GRP78-UPR sensor complex formation upon stressor removal. These results imply a gated UPR mechanism that tunes the overall cellular behavior to the accumulation of unfolded proteins.
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http://dx.doi.org/10.1016/j.bbrc.2017.04.069 | DOI Listing |
Zool Res
January 2025
National Key Laboratory for Swine Genetic Improvement and Germplasm Innovation, Ministry of Science and Technology of China, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China.
Pigeons and certain other avian species produce a milk-like secretion in their crop sacs to nourish offspring, yet the detailed processes involved are not fully elucidated. This study investigated the crop sacs of 225-day-old unpaired non-lactating male pigeons (MN) and males initiating lactation on the first day after incubation (ML). Using RNA sequencing, ribosome profiling, and single-cell transcriptome sequencing (scRNA-seq), we identified a significant up-regulation of genes associated with ribosome assembly and protein synthesis in ML compared to MN.
View Article and Find Full Text PDFFront Immunol
January 2025
Shanghai Frontiers Science Center for Drug Target Identification and Delivery, and the Engineering Research Center of Cell and Therapeutic Antibody of the Ministry of Education, School of Pharmaceutical Sciences, Shanghai Jiao Tong University, Shanghai, China.
Endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) are integral to T cell biology, influencing immune responses and associated diseases. This review explores the interplay between the UPR and T cell immunity, highlighting the role of these cellular processes in T cell activation, differentiation, and function. The UPR, mediated by IRE1, PERK, and ATF6, is crucial for maintaining ER homeostasis and supporting T cell survival under stress.
View Article and Find Full Text PDFNat Cell Biol
January 2025
Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, Bonn, Germany.
Mitochondria have to import a large number of precursor proteins from the cytosol. Chaperones keep these proteins in a largely unfolded state and guide them to the mitochondrial import sites. Premature folding, mitochondrial stress and import defects can cause clogging of import sites and accumulation of non-imported precursors, representing a critical burden for cellular proteostasis.
View Article and Find Full Text PDFAdv Protein Chem Struct Biol
January 2025
Department of Neurochemistry, National Institute of Mental Health and Neuro Sciences Hospital (NIMHANS), Institute of National Importance, Bangalore, Karnataka, India. Electronic address:
Alzheimer's disease (AD) is a prevalent neurodegenerative disease associated with dementia and neuronal impairments in brain. AD is characterized histopathologically by two hallmark lesions: abnormally phosphorylated Tau inside neurons as intracellular NFTs and extracellular accumulation of amyloid β peptide (Aβ). Furthermore, it is unable to clarify the distinction between the brief association between the development and build-up of Aβ and the commencement of illness.
View Article and Find Full Text PDFJ Med Chem
January 2025
Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States.
Alzheimer's disease (AD) is the most common form of dementia, marked by progressive brain degeneration and cognitive decline. A major pathological feature of AD is the accumulation of hyperphosphorylated tau (p-tau) in the form of neurofibrillary tangles (NFTs), which leads to neuronal death and neurodegeneration. P-tau also induces endoplasmic reticulum (ER) stress and activates the unfolded protein response, causing inflammation and apoptosis.
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