Search bioRxiv⌕ Search

bioRxiv · 10.1101/2024.09.04.610945

Chemical chaperone - sorbitol corrects cohesion and translational defects in the Roberts mutant

Abstract

The cohesin protein complex plays a very important role in chromosome segregation, transcription, DNA replication and chromosome condensation. Mutations in cohesin proteins give rise to a disease collectively referred to as Cohesinopathies. The major cause of Cohesinopathies arise due to defects associated with gene expression, that give rise to developmental disorders. In this study, we have used Saccharomyces cerevisiae to mimic the Cohesinopathy disorder Roberts syndrome with mutations (eco1W216G) homologous to that of humans (esco2). Our data suggests that polyol sugars like sorbitol, can repair misfolded proteins and reduce ER and proteostatic stress. We have used sorbitol as a chemical chaperone, to check how it can restore chromosome segregation, gene expression, misregulation, protein misfolding, autophagy and translational defects in the cohesin mutant of the Roberts phenotype. In silico screening has helped us identify the possible sites on eco1, which could be possibly altering the phenotypic traits. Article HighlightsIn presence of sorbitol O_LITemperature sensitivity of the Roberts mutants is rescued. C_LIO_LIChromosome cohesion defect is reduced. C_LIO_LITranslational defects are minimized. C_LIO_LIAutophagy is enhanced C_LIO_LIMolecular docking shows its interaction with the acetyltransferase domain of ESCO2. C_LI

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

BOSE, T., Marathe, S. D.. 2024-09-05. Chemical chaperone - sorbitol corrects cohesion and translational defects in the Roberts mutant. https://doi.org/10.1101/2024.09.04.610945

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Deep generative embeddings of gene expression and splicing reposition the interpretation of single-cell transcriptomic signatures

Single-cell transcriptomic analysis predominantly derives cell identity from gene expression analysis, while alternative splicing is processed separately despite its fundamental role for cell homeostasis. To overcome the limits of separate investigations, we developed a probabilistic deep learning framework, Crecerelle, enabling resolution of the contributions of gene expression and alternative splicing in each cell. Crecerelle learns cell embeddings from gene expressions and alternative splicing isoforms, to decipher their mutually dependent impact on the functional characterisation of cells in a data-driven manner, exemplified for the Tabula Muris dataset. This is enabled through a zero-and-N-inflated Dirichlet-Multinomial for a variational autoencoder that learns cell embeddings solely from splicing profiles, as well as a bi-modal variational autoencoder with a relevance-weighted mixture-of-experts variational posterior to consolidate the modality-specific contribution at single-cell level. Crecerelle reveals cell-type-specific isoform markers as well as subpopulations with unique isoforms and uncovers regulatory and disease-associated pathways not detected by gene expression analyses alone. This scalable and interpretable framework thus allows a more holistic study of transcriptomic regulation and will open a route to modality-relevance-weighted investigations across single-cell multiomics datasets and their influence on cellular homeostasis, tissue development and disease phenotypes.

cell biology↗

MHC Molecules on B Cell Microvilli Are Spatially Associated with IL-15Rα

Interleukin-15 (IL-15) trans-presentation (TP) by B cells is an important mechanism of T-cell activation; however, the spatial organisation of interleukin-15 receptor (IL-15R) relative to major histocompatibility complex (MHC) molecules on B-cell microvilli remains poorly understood. As microvilli protrude from the B-cell surface and may serve as sites of initial B cell-T-cell contact, the distribution of IL-15R and MHC molecules within these structures may be important during the earliest stages of T-cell recognition and activation. Here, we investigated the spatial association and molecular proximity of IL-15R with MHC class I and class II molecules on B-cell microvilli before immunological synapse formation, using confocal microscopy, stimulated emission depletion (STED) microscopy, stochastic optical reconstruction microscopy (STORM), and fluorescence lifetime imaging microscopy-based Forster resonance energy transfer (FLIM-FRET). Both MHC class I and class II molecules showed significant spatial association with IL-15R; however, the extent of colocalisation decreased as spatial resolution increased. STED microscopy revealed significant colocalisation between IL-15R and MHC class I, whereas STORM did not detect this association. In contrast, IL-15R and MHC class II remained significantly colocalised at both resolutions. FLIM-FRET further demonstrated molecular proximity between IL-15R and both MHC class I and class II molecules, with higher FRET efficiency observed for MHC class II. Collectively, these findings indicate that IL-15R is spatially organised in proximity to both MHC class I and class II molecules on B-cell microvilli before immunological synapse formation. This arrangement at potential sites of initial B-cell-T-cell contact may facilitate the coordination of IL-15 trans-presentation and antigen presentation during the earliest stages of B-cell-T-cell interactions.

cell biology↗

Pulsed-SILAC in single mouse embryos reveals early embryonic protein synthesis dynamics and phosphosite regulation

Early embryogenesis relies extensively on maternally deposited products until zygotic genome activation, yet the dynamics for the synthesis of new proteins in mammalian embryos remains poorly characterized. To address this, we applied pulsed stable isotope labelling by amino acids in cell culture (pSILAC) combined with narrow-window data-independent acquisition mass spectrometry to single mouse oocytes and embryos to resolve de novo protein synthesis during early embryogenesis. This revealed that the maternal proteome is not a static reservoir, with components of the subcortical maternal complex and amino acid transporters SLC7A1/2 being actively synthesized during the earliest developmental stages. Furthermore, phosphoproteomic analysis identified hundreds of previously unreported phosphosites and extensive regulation during the oocyte-to-embryo transition. Notably, phosphorylation of the PRC2-interacting KLP motif of EZHIP emerged as a potential regulatory mechanism, with modification of this region reducing EZHIP-PRC2 interaction and coinciding with H3K27me3 remodelling. Together, single embryo pSILAC revealed a maternal proteome that is continuously synthesized, recycled, and post-translationally regulated during early embryogenesis.

cell biology↗