Hsp70 family proteins are highly conserved chaperones involved in protein folding, degradation, targeting and translocation, and protein complex remodeling. They are comprised of an N-terminal nucleotide binding domain (NBD) and a C-terminal protein substrate binding domain (SBD). ATP binding to the NBD alters SBD conformation and substrate binding kinetics, but an understanding of the mechanism of interdomain communication has been hampered by the lack of a crystal structure of an intact chaperone. We report here the 2.6 angstroms structure of a functionally intact bovine Hsc70 (bHsc70) and a mutational analysis of the observed interdomain interface and the immediately adjacent interdomain linker. This analysis identifies interdomain interactions critical for chaperone function and supports an allosteric mechanism in which the interdomain linker invades and disrupts the interdomain interface when ATP binds.
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http://dx.doi.org/10.1016/j.molcel.2005.09.028 | DOI Listing |
J Proteome Res
January 2025
Department of Microbiology, Faculty of Biology, Universidad de Sevilla, Av. de la Reina Mercedes 6, 41012 Sevilla, Spain.
Prokaryotes and eukaryotes secrete extracellular vesicles (EVs) into the surrounding milieu to preserve and transport elevated concentrations of biomolecules across long distances. EVs encapsulate metabolites, DNA, RNA, and proteins, whose abundance and composition fluctuate depending on environmental cues. EVs are involved in eukaryote-to-prokaryote communication owing to their ability to navigate different ecological niches and exchange molecular cargo between the two domains.
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December 2024
Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, UK. Electronic address:
Nuclear receptors (NRs) regulate gene expression in response to hormonal signals, influencing diverse physiological processes and diseases. Structural and dynamics investigations based on X-ray crystallography, cryo-electron microscopy (cryo-EM), hydrogen-deuterium exchange mass spectrometry, and molecular dynamics simulations, have significantly deepened our understanding of the conformational states, dynamics, and interdomain interactions of multi-domain NRs. Structural studies have examined heterodimeric complexes such as peroxisome proliferator-activated receptor gamma (PPAR-γ) with retinoid X receptor alpha (RXRα), liver X receptor beta (LXRβ) with RXRα, and retinoic acid receptor beta (RARβ) with RXRα, as well as homodimers like hepatic nuclear factor 4 alpha (HNF-4α), androgen receptor (AR), and glucocorticoid receptor (GR).
View Article and Find Full Text PDFJ Chem Inf Model
December 2024
National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
Understanding how membrane composition influences the dynamics and function of transmembrane proteins is crucial for the comprehensive elucidation of cellular signaling mechanisms and the development of targeted therapeutics. In this study, we employed all-atom molecular dynamics simulations to investigate the impact of different membrane compositions on the conformational dynamics of the NKG2A/CD94/HLA-E immune receptor complex, a key negative regulator of natural killer cell cytotoxic activity. Our results reveal significant variations in the behavior of the immune complex structure across five different membrane compositions, which include POPC, POPA, DPPC, and DLPC phospholipids, and a mixed POPC/cholesterol system.
View Article and Find Full Text PDFSci Adv
November 2024
Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
The transduction of extracellular chemical signals into intracellular events relies on the communication between neighboring domains of membrane receptors. In the particular case of Cys-loop receptor channels, five short stretches of amino acids, one per subunit, link the extracellular and transmembrane domains in such a way that the ion permeability of the latter and the affinity for neurotransmitters of the former become tied to each other. Here, using direct functional approaches, we set out to understand the molecular bases of this crucial interdependence through the characterization of total loss-of-current mutations at the interface between domains.
View Article and Find Full Text PDFComput Med Imaging Graph
December 2024
Faculty of Applied Sciences, Macao Polytechnic University, 999078, Macao Special Administrative Region of China. Electronic address:
Despite the potential benefits of data augmentation for mitigating data insufficiency, traditional augmentation methods primarily rely on prior intra-domain knowledge. On the other hand, advanced generative adversarial networks (GANs) generate inter-domain samples with limited variety. These previous methods make limited contributions to describing the decision boundaries for binary classification.
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