Biology subjects

Zhao, H.

Publications and source records attributed to Zhao, H..

At least 379 records · Page 21Linked to original sources

bioRxiv2022

ame-miR-34 modulates the larval body weight and immune response of Apis mellifera workers to Ascosphara apis invasion

MiRNAs are critical regulators of numerous physiological and pathological processes. Ascosphaera apis exclusively infects bee larvae and causes chalkbrood disease. However, the function and mechanism of miRNAs in the bee larval response to A. apis infection is poorly understood. Here, ame-miR-34, a previously predicted miRNA involved in the response of Apis mellifera ligustica larvae to A. apis invasion, was subjected to molecular validation, and overexpression and knockdown were then conducted to explore the regulatory functions of ame-miR-34 in larval body weight and immune response. Stem-loop RT-PCR and Sanger sequencing confirmed the authenticity of ame-miR-34 in the larval gut of A. m. ligustica. RT-qPCR results demonstrated that compared with that in the uninfected larval guts, the expression level of ame-miR-34 was significantly downregulated (P < 0.001) in the guts of A. apis-infected 4-, 5-, and 6-day-old larvae, indicative of the remarkable suppression of host ame-miR-34 due to A. apis infection. In comparison with the corresponding negative control (NC) groups, the expression level of ame-miR-34 in the larval guts in the mimic-miR-34 group was significantly upregulated (P < 0.001), while that in the inhibi- tor-miR-34 group was significantly downregulated (P < 0.01). Similarly, effective overexpression and knockdown of ame-miR-34 were achieved. In addition, the body weights of 5- and 6-day-old larvae were significantly increased compared with those in the mimic-NC group; the weights of 5-day-old larvae in the inhibitor-miR-34 group were significantly decreased in comparison with those in the inhibitor-NC group, while the weights of 4- and 6-day-old larvae in the inhibi- tor-miR-34 group were significantly increased, indicating the involvement of ame-miR-34 in modulating larval body weight. Furthermore, the expression levels of both hsp and abct in the guts of A. apis-infected 4-, 5- and 6-day-old larvae were significantly upregulated after ame-miR-34 overexpression. In contrast, after ame-miR-34 knockdown, the expression levels of the aforementioned two key genes in the A. apis-infected 4-, 5- and 6-day-old larval guts were significantly downregu- lated. Together, the results demonstrated that effective overexpression and knockdown of ame-miR-34 in both noninfected and A. apis-infected A. m. ligustica larval guts could be achieved by the feeding method, and ame-miR-34 exerted a regulatory function in the host immune response to A. apis invasion through positive regulation of the expression of hsp and abct. Our findings not only provide a valuable reference for the functional investigation of bee larval miRNAs but also reveal the regulatory role of ame-miR-34 in A. mellifera larval weight and immune response. Additionally, the results of this study may provide a promising molecular target for the treatment of chalkbrood disease.

molecular biology↗

bioRxiv2022

Multi-trait genome-wide association analyses leveraging alcohol use disorder findings identify novel loci for smoking behaviors in the Million Veteran Program

Smoking behaviors and alcohol use disorder (AUD), moderately heritable traits, commonly co-occur in the general population. Single-trait genome-wide association studies (GWAS) have identified multiple loci for smoking and AUD. However, GWASs that have aimed to identify loci contributing to comorbid smoking and AUD have used small samples and thus have not been highly informative. Applying multi-trait analysis of GWASs (MTAG), we conducted a joint GWAS of smoking and AUD with data from the Million Veteran Program (N=318,694). By leveraging GWAS summary statistics for AUD, MTAG identified 21 genome-wide significant (GWS) loci associated with smoking initiation and 18 loci associated with smoking cessation compared to 16 and 8 loci, respectively, identified by single-trait GWAS. The novel loci for smoking behaviors identified by MTAG included those previously associated with psychiatric or substance use traits. Colocalization analysis identified 10 loci shared by AUD and smoking status traits, all of which achieved GWS in MTAG, including variants on SIX3, NCAM1, and near DRD2. Functional annotation of the MTAG variants highlighted biologically important regions on ZBTB20, DRD2, PPP6C, and GCKR that contribute to smoking behaviors. In contrast, MTAG of smoking behaviors and alcohol consumption (AC) did not enhance discovery compared with single-trait GWAS for smoking behaviors. We conclude that using MTAG to augment the power of GWAS enables the identification of novel genetic variants for commonly comorbid phenotypes, providing new insights into their pleiotropic effects on smoking behavior and AUD.

genetics↗

bioRxiv2022

The Molecular and Evolutionary Principles of Histone Folding in Eukarya and Archaea

Histones are the dominant proteins to compact and store DNA in both Eukarya and Archaea. For a long time, histones are observed to exist in the unit of dimers but diverge into different formats such as heterodimers in Eukarya or homodimers in Archaea. Here, by studying 11 types of histone proteins, both monomers and their dimeric complexes, using multiscale molecular dynamics (MD) simulations combined with NMR and circular dichroism experiments, we confirm the widely applied "folding upon binding" mechanism of histone structures. A histone dimer appears to form the longest 2 helices followed by other shorter helices and inter-molecular tertiary structures. We report an alternative conformation, namely, the inverted non-native dimer, which has a minimum free energy state. Protein sequence analysis indicates that the inverted conformation can be attributed to a hidden head-tail sequence symmetry underlying all histone proteins. This finding strongly support previously proposed histone evolution hypotheses. Finally, we separately used the MD-based AWSEM and AI-based AlphaFold-Multimer model to predict eukaryotic histone homodimer structures and performed extensive allatom MD simulations to examine their structural stabilities. Our results suggest that eukaryotic histones can also form stable homodimers, whereas their disordered tails-- the structurally asymmetrical region--may tip the balance towards the formation of heterotypic dimers.

biophysics↗

bioRxiv2022

Combined Developmental Toxicity Of Cyhalofop-butyl And Quizalofop-p-ethyl On The Zebrafish (Danio rerio) Embryos

Aryloxyphenoxypropionate herbicides have the characteristics of high efficiency, low toxicity, and safety to subsequent crops, and occupy an important position in the world herbicide market. Cyhalofop-butyl and quizalofop-p-ethyl are two representative herbicides, which are widely used in weed control. However, there is limited information on their combined toxicity to aquatic organisms. In this study, the developmental toxicity of cyhalofop-butyl and quizalofop-p-ethyl exposure in combination on zebrafish embryos was valuated to better understand the interaction between the that. The 96 h-LC50 (50% lethal concentration) of cyhalofop-butyl and quizalofop-p-ethyl on zebrafish embryos were 0.637 mg{middle dot}L-1 and 0.248 mg{middle dot}L-1, respectively. The combined effect of cyhalofop-butyl and quizalofop-p-ethyl was an antagonistic effect, and the 96 h-LC50 of zebrafish embryos was 1.043 mg{middle dot}L-1. Morphologically distinct pericardial edema and yolk cysts were observed after combined exposure, with significant effects on body length and heart rate in zebrafish embryos. At the same time, the mRNA levels of gene related to apoptosis and cardiac development also changed significantly. Therefore, we speculate that changes in genes related to apoptosis and cardiac development should be responsible for the abnormal development during embryonic development following co-exposure of cyhalofop-butyl and quizalofop-p-ethyl. HighlightsO_LICombined exposure caused deformities in zebrafish. C_LIO_LICombined exposure caused apoptosis in zebrafish. C_LIO_LICombined exposure altered the expression of apoptosis and cardiac-related genes in zebrafish. C_LI

pharmacology and toxicology↗

bioRxiv2022

Benchmarking Automated Cell Type Annotation Tools for Single-cell ATAC-seq Data

As single-cell chromatin accessibility profiling methods advance, scATAC-seq has become ever more important in the study of candidate regulatory genomic regions and their roles underlying developmental, evolutionary and disease processes. At the same time, cell type annotation is critical in understanding the cellular composition of complex tissues and identifying potential novel cell types. However, most existing methods that can perform automated cell type annotation are designed to transfer labels from an annotated scRNA-seq data set to another scRNA-seq data set, and it is not clear whether these methods are adaptable to annotate scATAC-seq data. Several methods have been recently proposed for label transfer from scRNA-seq data to scATAC-seq data, but there is a lack of benchmarking study on the performance of these methods. Here, we evaluated the performance of five scATAC-seq annotation methods on both their classification accuracy and scalability using publicly available single-cell datasets from mouse and human tissues including brain, lung, kidney, PBMC and BMMC. Using the BMMC data as basis, we further investigated the performance of these methods across different data sizes, mislabeling rates, sequencing depths and the number of cell types unique to scATAC-seq. Bridge integration, which is the only method that requires additional multimodal data and does not need gene activity calculation, was overall the best method and robust to changes in data size, mislabeling rate and sequencing depth. Conos was the most time and memory efficient method but performed the worst in terms of prediction accuracy. scJoint tended to assign cells to similar cell types and performed relatively poorly for complex datasets with deep annotations but performed better for datasets only with major label annotations. The performance of scGCN and Seurat v3 was moderate, but scGCN was the most time-consuming method and had the most similar performance to random classifiers for cell types unique to scATAC-seq.

bioinformatics↗

bioRxiv2022

Atypical peripheral actin band formation via overactivation of RhoA and Non-muscle myosin II in Mitofusin 2 deficient cells

Cell spreading and migration play central roles in many physiological and pathophysiological processes. We have previously shown that MFN2 regulates the migration of human neutrophillike cells via suppressing Rac activation. Here, we show that in mouse embryonic fibroblasts, MFN2 suppresses RhoA activation and supports cell polarization. After the initial spreading period, the wild-type cells polarize and migrate, whereas the Mfn2-/- cells maintain a circular shape. Increased cytosolic Ca2+ resulting from the loss of Mfn2 is directly responsible for this phenotype, which can be rescued by expressing an artificial tether to bring mitochondria and ER to close vicinity. Elevated cytosolic Ca2+ activates Ca2+/calmodulin-dependent protein kinase II, RhoA, and Myosin light-chain kinase, causing an over-activation of non-muscle myosin II and a formation of a prominent F-actin ring at the cell periphery and increased cell contractility. The formation of the peripheral actin band alters cell physics and is dependent on substrate rigidity. Our results provide a novel molecular basis to understand how MFN2 regulates distinct signaling pathways in different cells and tissue environments, which is instrumental in understanding and treating MFN2-related diseases.

cell biology↗

bioRxiv2022

Hybrid Synthesis of bioplastics polyhydroxybutyrate from carbon dioxide

The accelerating environmental crisis has intensified the demand for switching from traditional economy to a renewable one with a reduced carbon footprint. Here we reported a hybrid system, coupling chemical process of CO2 hydrogen reduction and biological process for polyhydroxybutyrate (PHB) synthesis, that utilized CO2 as a raw material to produce PHB in vitro. The synthetic pathway of PHB was optimized by screening more efficient methanol oxidases, high activity mutants of glycolaldehyde synthase and coordinating enzyme dosages in the pathway, which achieved the carbon yield of 93.6% for producing PHB from methanol. Finally, by combining with the chemical process from CO2 to methanol, a scaling-up bio-system was performed to convert CO2 into PHB, yielding 5.8 g/L with the productivity of 1.06 g-1L-1h-1. This approach represents a promising carbon-neutral way to produce biodegradable plastics.

synthetic biology↗

bioRxiv2022

Programming super DNA-enzyme molecules for on-demand enzyme activity modulation

Dynamic interactions of enzymes, including programmable configuration and cycling of enzymes, play important roles in the regulation of cellular metabolism. Here, we construct a super DNA-enzymes molecule (SDEM) that comprises at least two cascade enzymes and linked DNA strands to control and detect metabolism. We find that the programmable SDEM which comprises glucose oxidase (GOx) and horseradish peroxidase (HRP) has a 50-fold lower detection of limit and a 1.6-fold higher reaction rate than free enzymes. SDEM can be assembled and disassembled using a hairpin structure and a displacement DNA strand to complete multiple cycles. An entropically driven catalytic assembly (catassembly) enables different SDEMs to switch from SDEM with GOx and HRP cascades to SDEM with sarcosine oxidase (SOX) and HRP cascades by over six orders of magnitude less time than no catassembly to detect different metabolisms (glucose and sarcosine) on demand.

biochemistry↗

bioRxiv2022

Designing a Minimal Artificial Glycolytic Pathway

The canonical glycolysis generates two molecules of acetyl-coenzyme A (acetyl-CoA) from one glucose through eleven cascade biochemical reactions. Here, we designed and constructed a Minimal Artificial Glycolytic (MAG) pathway consisting of only three types of biochemical reactions, with phosphoketolase as the core, combined with phosphatase and isomerase as auxiliary enzymes. It could theoretically achieve a 100% carbon yield to acetyl-CoA from any monosaccharide by integrating one-carbon condensation reaction. We tested the MAG pathway in vitro and in vivo, demonstrating the catabolism of typical C1-C6 carbohydrates to acetyl-CoA with yields from 82% to 95%. This novel glycolytic pathway provides a promising route for biomanufacturing with stoichiometric productivity from multiple carbon sources in the future.

synthetic biology↗

bioRxiv2022

Genomic deletions and rearrangements in monkeypox virus from the 2022 outbreak, USA

Genomic surveillance of monkeypox virus (MPXV) during the 2022 outbreak has been mainly focused on single nucleotide polymorphism (SNP) changes. DNA viruses, including MPXV, have a lower SNP mutation rate than RNA viruses due to higher fidelity replication machinery. We identified a large genomic rearrangement in a MPXV sequence from a 2022 case in the state of Minnesota (MN), USA, from an abnormal, uneven MPXV read mapping coverage profile in whole-genome sequencing (WGS) data. We further screened WGS data of 206 U.S. MPXV samples and found seven (3.4 percent) sequenced genomes contained similar abnormal read coverage profiles that suggested putative large deletions or genomic rearrangements. Here, we present three MPXV genomes containing deletions ranging from 2.3 to 15 kb and four genomes containing more complex rearrangements. Five genomic changes were each only seen in one sample, but two sequences from linked cases shared an identical 2.3 kb deletion in the 3 terminal region. All samples were positive using VAC1 and Clade II (formerly West African)-specific MPXV diagnostic tests; however, large deletions and genomic rearrangements like the ones reported here have the potential to result in viruses in which the target of a PCR diagnostic test is deleted. The emergence of genomic rearrangements during the outbreak may have public health implications and highlight the importance of continued genomic surveillance.

genomics↗

bioRxiv2022

Molecular mechanism of substrate recognition by folate transporter SLC19A1

Folate (vitamin B9) is the coenzyme involved in one-carbon transfer biochemical reactions essential for cell survival and proliferation, with its inadequacy causing developmental defects or severe diseases. Notably, mammalian cells lack the ability to de novo synthesize folate but instead rely on its intake from extracellular sources via specific transporters or receptors, among which SLC19A1 is the ubiquitously expressed one in tissues. However, the mechanism of substrate recognition by SLC19A1 has been unclear. Here we report the cryo-EM structures of human SLC19A1 and its complex with 5-methyltetrahydrofolate at 3.5-3.6 [A] resolution and elucidate the critical residues for substrate recognition. In particular, we reveal that two variant residues among SLC19 subfamily members would designate the specificity for folate. Moreover, we identify intracellular thiamine pyrophosphate as the favorite coupled substrate for folate transport by SLC19A1. Together, this work has established the molecular basis of substrate recognition by this central folate transporter.

biochemistry↗

bioRxiv2022

Transcriptome-wide characterization of piRNAs during the developmental process of European honey bee larval guts

piRNAs play pivotal roles in suppressing transposons, maintaining genome stability, regulating gene expression, and modulating development and immunity. However, there are few piRNA-associated studies on honey bee, and the regulatory role of piRNAs in the development of bee guts is largely unknown. In this current work, the differential expression pattern of piRNAs during the developmental process of the European honey bee (Apis mellifera) was analyzed, and target prediction of differentially expressed piRNAs (DEpiRNAs) was then conducted, followed by investigation of regulatory networks and the potential function of DEpiRNAs in regulating larval gut development. Here, a total of 843 piRNAs were identified in the larval guts of A. mellifera; among these, 764 piRNAs were shared by 4- (Am4 group), 5- (Am5 group), and 6-day-old (Am6 group) larval guts, while 11, 67, and 1, respectively, were unique. The first base of piRNAs in each group had a cytosine (C) bias. Additionally, 61 up-regulated and 17 down-regulated piR-NAs were identified in the Am4 vs. Am5 comparison group, further targeting 9, 983 genes, which were involved in 50 GO terms and 142 pathways, while two up-regulated and five down-regulated piRNAs were detected in the Am5 vs. Am6 comparison group, further targeting 1, 936 genes, which were engaged in 41 functional terms and 101 pathways. piR-ame-742536 and piR-ame-856650 in the Am4 vs. Am5 comparison group as well as piR-ame-592661 and piR-ame-31653 in the Am5 vs. Am6 comparison group were found to link to the highest number of targets. Further analysis indicated that targets of DEpiRNAs in these two comparison groups were seven development-associated signaling pathways such as Hippo and Notch signaling pathways, seven immune-associated pathways including endocytosis and the Jak/STAT signaling pathway, and three energy metabolism pathways, namely sulfur metabolism, nitrogen metabolism, and oxidative phosphorylation. Moreover, the expression trends of five randomly selected DEpiRNAs were verified based on stem-loop RT-PCR and RT-qPCR. These results were suggestive of the overall alteration of piRNAs during the larval developmental process and demonstrated that DEpiRNAs potentially modulate development-, immune-, and energy metabolism-associated pathways by regulating expression of corresponding genes via target binding, further affecting the development of A. mellifera larval guts. Our data offer novel insights into the development of bee guts and lay a basis for clarifying the developmental mechanism underlying the larval guts of European honey bee.

molecular biology↗

bioRxiv2022

Dissecting aneuploidy phenotypes by constructing Sc2.0 chromosome VII and SCRaMbLEing synthetic disomic yeast

Aneuploidy compromises genomic stability, often leading to embryo inviability, and is frequently associated with tumorigenesis and aging. Different aneuploid chromosome stoichiometries lead to distinct transcriptomic and phenotypic changes, making it helpful to study aneuploidy in tightly controlled genetic backgrounds. By deploying the engineered SCRaMbLE system to the newly synthesized Sc2.0 megabase chromosome VII (synVII), we constructed a synthetic disomic yeast and screened hundreds of SCRaMbLEd derivatives with diverse chromosomal rearrangements. Phenotypic characterization and multi-omics analysis revealed that fitness defects associated with aneuploidy could be restored by i) removing most of the chromosome content, or ii) modifying specific regions in the duplicated chromosome. These findings indicate that both chromosome copy number and chromosomal regions contribute to the aneuploidy-related phenotypes, and the synthetic yeast resource opens new paradigms in studying aneuploidy. In briefUse of SCRaMbLE and newly synthesized Mb-scale Sc2.0 chromosome VII enables insights into genotype/phenotype relationships associated with aneuploidy HighlightsO_LIDe novo design and synthesis of a Mb-scale synthetic yeast chromosome VII, carrying 11.8% sequence modifications and representing nearly 10% of the yeast genome. C_LIO_LIA disomic yeast (n + synVII) is constructed for dissecting the aneuploidy phenotype C_LIO_LISCRaMbLE enables systematic exploration of regions causing aneuploidy phenotypes C_LIO_LIChromosomal copy number and content both contribute to aneuploidy phenotypes C_LIO_LIA 20 Kb deletion on the right arm of synVII leads to fitness improvement linked to up-regulation of protein synthesis C_LI

synthetic biology↗

bioRxiv2022

Nucleotide and structural polymorphisms of the eastern oyster genome paint a mosaic of divergence, selection, and human impacts

The eastern oyster, Crassostrea virginica, is a valuable fishery and aquaculture species that provides critical services as an ecosystem engineer. Oysters have a life-history that promotes high genetic diversity and gene flow while also occupying a wide range of habitats in variable coastal environments from the southern Gulf of Mexico to the southern waters of Atlantic Canada. To understand the interplay of genetic diversity, gene flow, and intense environmental selection, we used whole genome re-sequencing data from 90 individuals across the eastern United States and Gulf of Mexico, plus 5 selectively bred lines. Our data confirmed a large phylogeographic break between oyster populations in the Gulf of Mexico and the Atlantic coast of the USA. We also demonstrated that domestication has artificially admixed genetic material between the two ocean basins, and selected lines with admixed ancestry continue to maintain heterozygosity at these sites through several generations post admixture, possibly indicating relevance to desirable aquaculture traits. We found that genetic and structural variation are high in both wild and selected populations, but we also demonstrated that, when controlling for domestication admixture across ocean basins, wild populations do have significantly higher levels of nucleotide diversity and copy number variation than selected lines. Within the Atlantic coast, we detected subtle but distinct population structure, introgression of selected lines within wild individuals, an interaction between structural variation and putatively adaptive population structure, and evidence of candidate genes responding to selection from salinity. Our study highlights the potential for applying whole genome sequencing to highly polymorphic species and provides a road map for future work examining the genome variation of eastern oyster populations.

evolutionary biology↗

bioRxiv2022

A second unveiling: haplotig masking of the eastern oyster genome improves population-level inference

Genome assembly can be challenging for species that are characterized by high amounts of polymorphism, heterozygosity, and large effective population sizes. High levels of heterozygosity can result in genome mis-assemblies and a larger than expected genome size due to the haplotig versions of a single locus being assembled as separate loci. Here, we describe the first chromosome-level genome for the eastern oyster, Crassostrea virginica. Publicly released and annotated in 2017, the assembly has a scaffold N50 of 54 mb and is over 97.3% complete based on BUSCO analysis. The genome assembly for the eastern oyster is a critical resource for foundational research into molluscan adaptation to a changing environment and for selective breeding for the aquaculture industry. Subsequent resequencing data suggested the presence of haplotigs in the original assembly, and we developed a post hoc method to break up chimeric contigs and mask haplotigs in published heterozygous genomes and evaluated improvements to the accuracy of downstream analysis. Masking haplotigs had a large impact on SNP discovery and estimates of nucleotide diversity and had more subtle and nuanced effects on estimates of heterozygosity, population structure analysis, and outlier detection. We show that haplotig-masking can be a powerful tool for improving genomic inference, and we present an open, reproducible resource for the masking of haplotigs in any published genome.

genomics↗

bioRxiv2022

An uncertainty-based interpretable deep learning framework for breast cancer outcomes prediction

Accurate prediction of breast cancer outcomes is important for selecting appropriate treatment, which can prolong the survival period of the patients and improve the life quality. Recently, different deep learning-based methods are carefully designed for cancer outcomes prediction. However, the applications of these methods are still challenging due to the model interpretability. In this study, we proposed a novel multi-task deep neural network UISNet to interpret the feature importance of the prediction model by an uncertainty-based integrated gradients algorithm. Additionally, UISNet improves the prediction accuracy by introducing the prior biological pathway knowledge and utilizing the patients heterogeneity information. By applications to seven breast cancer public datasets, the method was shown to outperform state-of-the-art methods by achieving a 5.79% higher C-index value on average. For the identified genes based on the interpretable model, 11 out of the top 20 genes have been proved to be associated with breast cancer by literature review. The comprehensive tests indicated that our proposed method is accurate and robust to predict breast cancer outcomes, and is an effective way to identify the prognosis-related genes. The method codes are available at: https://github.com/chh171/UISNet.

bioinformatics↗

bioRxiv2022

APE1 assembles biomolecular condensates to promotethe ATR-Chk1 DNA damage response in nucleolus

Multifunctional protein APE1/APEX1/HAP1/Ref-1 (designated as APE1) plays important roles in nuclease-mediated DNA repair and redox regulation in transcription. However, it is unclear how APE1 regulates the DNA damage response (DDR) pathways and influences genome integrity directly or indirectly. Here we show that siRNA-mediated APE1-knockdown or APE1 inhibitor treatment attenuates the ATR-Chk1 DDR under stress conditions in multiple immortalized cell lines. Congruently, APE1 overexpression (APE1-OE) activates the ATR DDR under unperturbed conditions, which is independent of APE1 nuclease and redox functions. Structural and functional analysis reveals a direct requirement of the extreme N-terminal 33 amino acids (NT33) within APE1 in the assembly of distinct biomolecular condensates in vitro and DNA/RNA-independent activation of the ATR DDR. Overexpressed APE1 co-localizes with nucleolar NPM1 and assembles biomolecular condensates in nucleoli in cancer but not non-malignant cells, which recruits ATR and its direct activator molecules TopBP1 and ETAA1. APE1 W119R mutant is deficient in nucleolar condensation and liquid-liquid phase separation and is incapable of activating nucleolar ATR DDR. Lastly, APE1-OE-induced nucleolar ATR DDR activation leads to compromised ribosomal RNA transcription and reduced cell viability. Taken together, we propose distinct mechanisms by which APE1 regulates ATR DDR pathways and functions in genome integrity maintenance.

molecular biology↗

bioRxiv2022

Cryo-EM complex structure of active GPR75 with a nanobody

Although there has been enormous progress in the last half-century in the drug discovery targeting obesity and associated co-morbidities, the clinical treatment of obesity remains tremendously challenging. GPR75 is an orphan receptor and is suggested to be a potential novel target for the control of obesity and related metabolic disorders. Inhibition of the GPR75 signaling pathway by small molecules, antibodies, or genetic manipulations may provide a therapeutic strategy for obesity. Here, we report the active-like Cryo-EM structure of human GPR75 with an intracellular nanobody, which reveals the receptor activation mechanism. The extensive interaction network required to achieve the active structure helps explain the allosteric coupling between the orthosteric pocket and the G-protein coupling domain. The well-defined orthosteric ligand binding pocket of human GPR75 provides a structural basis for anti-obesity drug discovery.

biophysics↗