Biology subjects

Gui, M.

Publications and source records attributed to Gui, M..

8 recordsLinked to original sources

bioRxiv2026

Structural streamlining of axonemal doublet microtubules in Plasmodium male gametes

Male gametogenesis in malaria parasites produces up to eight flagellated gametes within approximately 15 min, requiring de novo construction of motile axonemes on an unusually short timescale. Here we combine cellular cryo-electron tomography, high-resolution cryo-EM, proteomics, and parasite genetics to define the molecular architecture and assembly states of the Plasmodium male gamete axoneme. The doublet microtubules retain the principal surface-associated motility modules but contain a markedly reduced luminal microtubule inner protein network. Their inner junction lacks PACRG and is instead organized by CFAP20 and CFAP52, whose combined loss disrupts doublet integrity and exflagellation. We further identify a calmodulin protein at the outer dynein arm docking region and show that outer dynein arms accumulate progressively during gametogenesis. These findings establish distinct form of axonemal remodeling in Plasmodium and reveal the ordered assembly of structural and motor modules during rapid male gamete formation.

cell biology↗

bioRxiv2026

Hierarchical Assembly of Native Cytoplasmic Lattices Revealed by Cryo-EM

Oocytes depend on maternal factors for maturation and early embryogenesis. Cytoplasmic lattices (CPLs) are distinctive fibrillar structures in mammalian oocyte cytoplasm implicated in maternal factor storage and developmental competence, yet their molecular composition and architecture remain elusive. Here, we use cryo-electron microscopy to resolve the high-resolution structure of native mouse oocyte CPLs. We identify 14 intrinsic components of multiple copies that assemble into filaments in which PADI6-mediated self-assembly and two subtypes of subcortical maternal complexes (SCMCs) form the core scaffold. Unexpectedly, we discover that /{beta}-tubulin dimers and two autoinhibited ubiquitination modules (UHRF1-UBE2D3, SKP1-FBXW18) are internal components of CPLs. We also uncover multivalent interactions that organize adjacent CPL filaments into higher-order helical bundles. By integrating CPL structure with biochemical and proteomic data, we propose a hierarchical assembly mechanism of CPLs, from subcomplexes to filaments to supramolecular lattices. Our study offers mechanistic insights into how maternal proteins are spatially organized to ensure successful early embryonic development and provides a structural foundation for understanding female infertility related to CPL-associated gene mutations.

developmental biology↗

bioRxiv2024

TFE3 fusions direct an oncogenic transcriptional program that drives OXPHOS and unveils vulnerabilities in translocation renal cell carcinoma

Translocation renal cell carcinoma (tRCC) is an aggressive subtype of kidney cancer driven by TFE3 gene fusions, which act via poorly characterized downstream mechanisms. Here we report that TFE3 fusions transcriptionally rewire tRCCs toward oxidative phosphorylation (OXPHOS), contrasting with the highly glycolytic metabolism of most other renal cancers. This TFE3 fusion-driven OXPHOS program, together with heightened glutathione levels found in renal cancers, renders tRCCs sensitive to reductive stress - a metabolic stress state induced by an imbalance of reducing equivalents. Genome-scale CRISPR screening identifies tRCC-selective vulnerabilities linked to this metabolic state, including EGLN1, which hydroxylates HIF-1 and targets it for proteolysis. Inhibition of EGLN1 compromises tRCC cell growth by stabilizing HIF-1a and promoting metabolic reprogramming away from OXPHOS, thus representing a vulnerability to OXPHOS-dependent tRCC cells. Our study defines a distinctive tRCC-essential metabolic program driven by TFE3 fusions and nominates EGLN1 inhibition as a therapeutic strategy to counteract fusion-induced metabolic rewiring.

cancer biology↗

bioRxiv2024

Decoding the anti-aging effect of retinol in reshaping the human skin microbiome niches

Retinol has been widely added to skincare products due to its ability to promote the proliferation of skin keratinocytes and regulate skin cell collagen expression. While it is known the skin harbors a myriad of commensal bacteria, the impact of retinol on the skin microbiome, as well as the role of the skin microbiome in mediating the anti-aging properties of retinol, remains poorly understood. In this study, we incorporated phenomics, metagenomics and metabolomics to explore the human skin alterations during the anti-aging process mediated by retinol, and potential interactions between retinol, skin microbiome and metabolites. Topical retinol significantly improved skin conditions, including enhancing skin hydration, acidifying the epidermis, strengthening the skin barrier, and reducing the number and volume of wrinkles. Furthermore, retinol also reshaped the skin microecology by altering the structure and function of the skin microbiome as well as the host and microbial metabolites. Through GEM construction, we identified 2 skin microorganism, Sericytochromatia sp. and Corynebacterium kefirresidentii capable of oxidizing retinol to retinal. Over 10 skin microbes can utilize UDP-glucose as a carbon source, potentially accelerating RAG hydrolysis and increasing glucuronic acid consumption. The retinoic acid and retinol generated by RAG hydrolysis are reused by skin cells and microbes, enhancing retinol metabolism and its effective duration. This combined effect between the skin microbiome and retinol improves skin condition and anti-aging efficacy.

microbiology↗

bioRxiv2024

The catabolism of alanine and glutamate ensure proper sporulation by respectively preventing premature germination and providing energy sources

Sporulation as a typical bacterial differentiation process has been studied for decades. However, two crucial aspects of sporulation, (i) the energy sources supporting the process, and (ii) the maintenance of spore dormancy throughout sporulation, are scarcely explored. Here, we reported the crucial role of RocG-mediated glutamate catabolism in regulating mother cell lysis, a critical step for successful sporulation, likely by providing energy metabolite ATP. Notably, rocG overexpression resulted in an excessive ATP accumulation in sporulating cells, leading to adverse effects on future spore properties, e.g. increased germination efficiency, reduced DPA content, and lowered heat resistance. Additionally, we revealed that Ald-mediated alanine metabolism decreased the typical germinant L-alanine concentration in sporulating environment, thereby preventing premature germination and maintaining spore dormancy. Our data inferred that sporulation was a highly orchestrated biological process requiring a delicate balance in diverse metabolic pathways, hence ensuring both the completion of sporulation and production of high-quality spores.

microbiology↗

bioRxiv2022

Chemotherapy drugs induce different gut microbiota disorder pattern and NODs/RIP2/NF-κB signaling pathway activation that lead to different degrees of intestinal injury

5-Fluorouracil (5-FU), irinotecan (CPT-11), oxaliplatin (L-OHP) and calcium folinate (CF) are the widely used chemotherapy drugs to treat colorectal cancer. However, the use of chemotherapy is often accompanied by intestinal inflammation and gut microbiota disorder. Moreover, the change of gut microbiota may lead to destruction of the intestinal barrier, which contributes to the severity of intestinal injury. There was no detailed comparison of intestinal injury and gut microbiota disorder among 5-FU, CPT-11, L-OHP and CF, which is not benefit for the development of targeted detoxification therapy after chemotherapy. In this project, a model of chemotherapy-induced intestinal injury in tumor-bearing mice was established by intraperitoneal injection of chemotherapy drugs at a clinically equivalent dose. 16S rDNA sequencing was used to detect gut microbiota. We found that 5-FU, CPT-11 and L-OHP caused intestinal injury, inflammatory cytokine (IFN-{gamma}, TNF-, IL-1{beta}, and IL-6) secretion, and gut microbiota disorder. Importantly, we established a complex but clear network between the gut microbiota change pattern and intestinal damage degree induced by different chemotherapy drugs. L-OHP caused the most severe damage in intestine and disorder of gut microbiota, and showed considerable overlap of the microbiota change pattern with 5-FU and CPT-11. The phylogenetic investigation of communities by reconstruction of unobserved states, V1.0 (PICRUSt) analysis showed that the microbiota disorder pattern induced by 5-FU, CPT-11 and L-OHP was related to the NOD like signaling pathway. Therefore, we detected the protein expression of the NODs/RIP2/NF-{kappa}B signaling pathway and found that L-OHP activated that pathway highest. Furthermore, by RDA/CCA analysis, we found that Bifidobacterium, Akkermansia, Allobaculum, Catenibacterium, Mucispirillum, Turicibacter, Helicobacter, Proteus, Escherichia Shigella, Alloprevotealla, Vagococcus, Streptococcus and Candidatus Saccharimonas were highly correlated with the NODs/RIP2/NF-{kappa}B signaling pathway, and influenced by chemotherapy drugs. IMPORTANCEThe chemotherapy-induced intestinal injury limit drugs clinical use. Intestinal injury involves multiple signaling pathways and the disruption of microbiota. Our results suggest that the degree of intestinal injury caused by different drugs of the first-line colorectal chemotherapy regimen is related to the change pattern of microbiota. Moreover, the NODs/RIP2/NF-{kappa}B signaling pathway was activated in different degrees is also related to the change pattern of microbiota. We found L-OHP caused the most severe change of gut microbiota, and showed considerable overlap of the microbiota changes pattern with 5-FU and CPT-11. Here, we have established a network of different chemotherapy drugs, gut microbiota and NODs/RIP2/NF-{kappa}B signaling pathway, which may provide a new basis for further elucidating the mechanism and clinical treatment of intestinal injury caused by chemotherapy.

molecular biology↗

bioRxiv2020

Cryo-EM structure of an activated GPCR-G protein complex in lipid nanodiscs

G protein coupled receptors (GPCRs) are the largest superfamily of transmembrane proteins and the targets of over 30% of currently marketed pharmaceuticals1,2. Although several structures have been solved for GPCR-G protein complexes3-17, structural studies of the complex in a physiological lipid membrane environment are lacking. Additionally, most previous studies required additional antibodies/nanobodies and/or engineered G proteins for complex stabilization. In the absence of a native complex structure, the underlying mechanism of G protein activation leading to GDP/GTP exchange remains unclear. Here, we report cryo-EM structures of lipid bilayer-bound complexes of neurotensin, neurotensin receptor 1, and Gi1{beta}1{gamma}1 protein in two conformational states, resolved to 4.1 and 4.2 [A] resolution. The structures were determined without any stabilizing antibodies/nanobodies, and thus provide a native-like platform for understanding the structural basis of GPCR-G protein complex formation. Our structures reveal an extended network of protein-protein interactions at the GPCR-G protein interface compared to in detergent micelles, defining roles for the lipid membrane in modulating the structure and dynamics of complex formation, and providing a molecular explanation for the stronger interaction between GPCR and G protein in lipid bilayers. We propose a detailed allosteric mechanism for GDP release, providing new insights into the activation of G proteins for downstream signaling under near native conditions.

molecular biology↗

bioRxiv2019

Structure and activation mechanism of the BBSome membrane-protein trafficking complex

Bardet-Biedl syndrome (BBS) is an incurable ciliopathy caused by the failure to correctly establish or maintain cilia-dependent signaling pathways. Eight proteins associated with BBS assemble into the BBSome, a master regulator of the ciliary membrane proteome. We report the electron cryomicroscopy (cryo-EM) structures of the native bovine BBSome in inactive and active states at 3.1 and 3.5 [A] resolution, respectively. In the active state, the BBSome is bound to an Arf-family GTPase (ARL6/BBS3) that recruits the BBSome to ciliary membranes. ARL6 recognizes a composite binding site formed by BBS1 and BBS7 that is occluded in the inactive state. Activation requires an unexpected swiveling of the {beta}-propeller domain of BBS1, the key subunit implicated in substrate recognition, which widens a central cavity of the BBSome. Structural mapping of disease-causing mutations suggests that pathogenesis predominantly results from disruption of autoinhibition and activation.

biophysics↗