The genetic material of eukaryotes is segregated into transcriptionally active euchromatin and silent heterochromatin compartments. The spatial arrangement of chromatin compartments evolves over the course of cellular life in a process that remains poorly understood. The latest nuclear imaging experiments reveal a number of dynamical signatures of chromatin that are reminiscent of active multiphase liquids. This includes the observations of viscoelastic response, coherent motions, Ostwald ripening, and coalescence of chromatin compartments. There is also growing evidence that liquid-liquid phase separation of protein and nucleic acid components is the underlying mechanism for the dynamical behavior of chromatin. To dissect the organizational and dynamical implications of chromatin's liquid behavior, we have devised a phenomenological field-theoretic model of the nucleus as a multiphase condensate of liquid chromatin types. Employing the liquid chromatin model of the Drosophila nucleus, we have carried out an extensive set of simulations with an objective to shed light on the dynamics and chromatin patterning observed in the latest nuclear imaging experiments. Our simulations reveal the emergence of experimentally detected mesoscale chromatin channels and spheroidal droplets which arise from the dynamic interplay of chromatin type to type interactions and intermingling of chromosomal territories. We also quantitatively reproduce coherent motions of chromatin domains observed in displacement correlation spectroscopy measurements which are explained within the framework of our model by phase separation of chromatin types operating within constrained intrachromosomal and interchromosomal boundaries. Finally, we illuminate the role of heterochromatin-lamina interactions in the nuclear organization by showing that these interactions enhance the mobility of euchromatin and indirectly introduce correlated motions of heterochromatin droplets.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8633720 | PMC |
http://dx.doi.org/10.1016/j.bpj.2021.10.012 | DOI Listing |
Reprod Biol Endocrinol
January 2025
Department of Gynecology and Reproductive Medicine, Karolinska University Hospital, Huddinge, Stockholm, 14183, Sweden.
Background: A didelphic uterus represents a unique and infrequent congenital condition in which a woman possesses two distinct uteri, each with its own cervix. This anomaly arises due to partial or incomplete merging of the Müllerian ducts during the developmental stages in the womb. Accounting for uterine malformations, a didelphic uterus is a relatively rare condition, affecting approximately 0.
View Article and Find Full Text PDFTrends Biochem Sci
January 2025
Department of Chemistry, Syracuse University, Syracuse, NY 13244, USA; Department of Biology, Syracuse University, Syracuse, NY 13244, USA; Bioinspired Institute, Syracuse University, Syracuse, NY 13244, USA; Interdisciplinary Neuroscience Program, Syracuse University, Syracuse, NY 13244, USA. Electronic address:
Protein quality control (PQC) mechanisms including the ubiquitin (Ub)-proteasome system (UPS), autophagy, and chaperone-mediated refolding are essential to maintain protein homeostasis in cells. Recent studies show that these PQC mechanisms are further modulated by biomolecular condensates that sequester PQC components and compartmentalize reactions. Accumulating evidence points towards the PQC machinery playing a pivotal role in regulating the assembly, disassembly, and viscoelastic properties of several condensates.
View Article and Find Full Text PDFJ Mol Biol
January 2025
Elettra Sincrotrone Trieste, Italy; The Wohl Institute, King's College London, 5 Cutcombe Rd, SW59RT London, UK. Electronic address:
Annexins are a family of calcium-dependent phospholipid-binding proteins involved in crucial cellular processes such as cell division, calcium signaling, vesicle trafficking, membrane repair, and apoptosis. In addition to these properties, Annexins have also been shown to bind RNA, although this function is not universally recognized. In the attempt to clarify this important issue, we employed an integrated combination of experimental and computational approaches.
View Article and Find Full Text PDFJ Chromatogr A
December 2024
School of Chemistry and Chemical Engineering/State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, Shihezi University, Shihezi 832003, PR China. Electronic address:
Molecularly imprinted nanocomposite membranes (MINMs) have shown great superiority in selective separation of acteoside (ACT) from phenylethanoid glycosides in Cistanche tubulosa. Herein, ACT-based MINMs (A-MINMs) with coral reef-like imprinted structure were proposed and developed for specifically separating ACT molecules. The nanospheres with hydrophilic multicores (NHMs) were introduced into polyvinylidene fluoride (PVDF) powders to obtain NHMs@PVDF membranes by a phase inversion method.
View Article and Find Full Text PDFFood Chem
December 2024
Department of Chemistry, Faculty of Sciences, Erciyes University, Kayseri, Turkiye; Technology Research and Application Center (TAUM), Erciyes University, Kayseri, Turkiye; Turkish Academy of Sciences (TUBA), Cankaya, Ankara, Turkiye; Khazar University Nano BioAnalytical Chemistry Center (NBAC), Mahsati Str 41, AZ-1096 Baku, Azerbaijan.
In this study, a green synthesis method for synthesizing a novel nanocomposite (CuO/g-C₃N₄/Fe₃O₄) utilizing renewable dragon fruit peels as the primary raw material was developed. Hydrothermal and thermal decomposition techniques were used for nanocomposite synthesis. This nanocomposite was subsequently employed for the separation and preconcentration of Cd(II) from various environments, including food and water samples.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!