Biology subjects

Qiao, S.

Publications and source records attributed to Qiao, S..

28 records · Page 2Linked to original sources

bioRxiv2020

Bat and pangolin coronavirus spike glycoprotein structures provide insights into SARS-CoV-2 evolution

In recognizing the host cellular receptor and mediating fusion of virus and cell membranes, the spike (S) glycoprotein of coronaviruses is the most critical viral protein for cross-species transmission and infection. Here we determined the cryo-EM structures of the spikes from bat (RaTG13) and pangolin (PCoV_GX) coronaviruses, which are closely related to SARS-CoV-2. All three receptor-binding domains (RBDs) of these two spike trimers are in the "down" conformation, indicating they are more prone to adopt this receptor-binding inactive state. However, we found that the PCoV_GX, but not the RaTG13, spike is comparable to the SARS-CoV-2 spike in binding the human ACE2 receptor and supporting pseudovirus cell entry. Through structure and sequence comparisons, we identified critical residues in the RBD that underlie the different activities of the RaTG13 and PCoV_GX/SARS-CoV-2 spikes and propose that N-linked glycans serve as conformational control elements of the RBD. These results collectively indicate that strong RBD-ACE2 binding and efficient RBD conformational sampling are required for the evolution of SARS-CoV-2 to gain highly efficient infection.

biophysics↗

bioRxiv2020

Cryo-EM structures of HKU2 and SADS-CoV spike glycoproteins and insights into coronavirus evolution

A new porcine coronavirus SADS-CoV was recently identified from suckling piglets with severe diarrhea in southern China and its genome sequence is most identical (~95% identity) to that of bat -coronavirus HKU2. It again indicates bats are the natural reservoir of many coronaviruses that have great potential for cross-species transmission to animals and humans by recombination and/or mutation. Here we report the cryo-EM structures of HKU2 and SADS-CoV spike glycoprotein trimers at 2.38 [A] and 2.83 [A] resolution, respectively. HKU2 and SADS-CoV spikes exhibit very high structural similarity, with subtle differences mainly distributed in the NTD and CTD of the S1 subunit responsible for cell attachment and receptor binding. We systematically analyzed and compared the NTD, CTD, SD1 and SD2 domains of the S1 subunit and the S2 subunit of HKU2 spike with those of -, {beta}-, {gamma}-, and {delta}-coronavirus spikes. The results show that the NTD and CTD of HKU2/SADS-CoV are probably the most ancestral in the evolution of spike. Although the S2 subunit mediating membrane fusion is highly conserved, the connecting region after fusion peptide in HKU2/SADS-CoV S2 subunit also adopts a conformation distinct from other coronaviruses. These results structurally demonstrate a close evolutionary relationship between HKU2 /SADS-CoV and {beta}-coronavirus spikes and provide new insights into the evolution and cross-species transmission of coronaviruses.

biochemistry↗

bioRxiv2019

Interconversion between Anticipatory and Active GID E3 Ubiquitin Ligase Conformations via Metabolically Driven Substrate Receptor Assembly

Cells respond to environmental changes by toggling metabolic pathways, preparing for homeostasis, and anticipating future stresses. For example, in Saccharomyces cerevisiae, carbon stress-induced gluconeogenesis is terminated upon glucose availability, a process that involves the multiprotein E3 ligase, GIDSR4, recruiting N-termini and catalyzing ubiquitylation of gluconeogenic enzymes. Here, genetics, biochemistry, and cryo electron microscopy define molecular underpinnings of glucose-induced degradation. Unexpectedly, carbon stress induces an inactive anticipatory complex (GIDAnt), which awaits a glucose-induced substrate receptor to form the active GIDSR4. Meanwhile, other environmental perturbations elicit production of an alternative substrate receptor assembling into a related E3 ligase complex. The intricate structure of GIDAnt enables anticipating and ultimately binding various N-degron targeting (i.e. \"N-end rule\") substrate receptors, while the GIDSR4 E3 forms a clamp-like structure juxtaposing substrate lysines with the ubiquitylation active site. The data reveal evolutionarily conserved GID complexes as a family of multisubunit E3 ubiquitin ligases responsive to extracellular stimuli.

molecular biology↗

bioRxiv2019

Extraction of genome-wide reads distribution pattern through whole genome sequencing of cell-free DNA for tracking tissue-of-origin in cancer patients

Somatic mosaicism is widespread among tissues and could indicate distinct tissue origins of circulating cell-free DNA (cfDNA), DNA fragments released by lytic cells into the blood. By investigating the alignment patterns of whole genome sequencing reads with the genomic DNA of different tissues, we found that the read distributions formed type-specific patterns in some regions as a result of somatic mosaicism. We then utilized this information to construct a tissue-of-origin mapping model and evaluated its predictive performance on whole genome sequencing data from tissue and cfDNA samples. In total, 1,545 tissue samples associated with 13 cancer types were included, and identification of the tissue of origin achieved a specificity of 82% and a sensitivity of 80%. Furthermore, a total of 30 cfDNA samples from lung cancer and liver cancer patients and healthy controls were analyzed to predict their tissues of origin with a specificity of 87% and a sensitivity of 87%. Our results show that read distribution patterns from whole genome sequencing could be used to identify cfDNA tissues of origin with high accuracy, suggesting the potential application of our model to early cancer detection and diagnosis.

bioinformatics↗

bioRxiv2019

A Causal Network Analysis of Neuromodulation in the Cortico-Subcortical Limbic Network

Neural decoding and neuromodulation technologies hold great promise for treating mood and other brain disorders in next-generation therapies that manipulate functional brain networks. Here, we perform a novel causal network analysis to decode multiregional communication in the primate mood processing network and determine how neuromodulation, short-burst tetanic microstimulation (SB-TetMS), alters multiregional network communication. The causal network analysis revealed a mechanism of network excitability that regulates when a sender stimulation site communicates with receiver sites. Decoding network excitability from neural activity at modulator sites predicted sender-receiver communication while SB-TetMS neuromodulation specifically disrupted sender-receiver communication. These results reveal specific network mechanisms of multiregional communication and suggest a new generation of brain therapies that combine neural decoding to predict multiregional communication with neuromodulation to disrupt multiregional communication.\n\nOne Sentence SummaryDecoding and modulating multiregional network communication.

neuroscience↗

bioRxiv2019

Lentivirus-mediated long-term overexpression of specific microRNA in mammalian cells

The establishment of a method that would overexpress or suppress of specific microRNA activity is essential for the functional analysis of these molecules and for the development of miRNA therapeutic applications. There already exist excellent ways to inhibit miRNA function in vitro and in vivo by overexpressing miRNA target sequences, which include miRNA decoys, sponges, or antagomirs that are complementary to an miRNA seed region. Conversely, no methods to induce stable gain-of-function phenotypes for specific miRNAs have, as yet, been reported. Furthermore, the discovery of complementary miRNA pairs raises suspicion regarding the existing methods used for miRNA overexpression. In our study, we will study whether the traditional methods for miRNA overexpression can be used for specific miRNA overexpression while complementary miRNA pairs exist. In addition, we test various miRNA-expression cassettes that were designed to efficiently overexpress specific miRNA through the shRNA lentivirus expression system. We report the optimal conditions that were established for the design of such miRNA-expression cassettes. We finally demonstrate that the miRNA-expression cassettes achieve efficient and long-term overexpression of specific miRNAs. Meanwhile, our results also support the notion that miRNA-miRNA interactions are implicated in potential, mutual regulatory patterns and beyond the seed sequence of miRNA, extensive pairing interactions between a miRNA and its target also lead to target-directed miRNA degradation. Our results indicate that our method offers a simple and efficient means to over-express the specific miRNA with long-term which will be very useful for future studies in miRNA biology, as well as contributed to the development of miRNA-based therapy for clinical applications.

molecular biology↗

bioRxiv2019

Differential effects of Doxorubicin and Actinomycin D on the stability of RNA binding proteins, RBM10 and RBM5: Actinomycin D promotes the nuclear speckles targeting of RBM10 and RBM5 through the novel structural elements.

BackgroundRNA binding motif (RBM) proteins, RBM10v1, RBM10v2 and RBM5 share a high degree of the conserved domains. So far, the drug-sensitivities of the RBMs in tumor cells have not been fully examined.\n\nObjectiveThe expression profiles of RBM10 and RBM5 in several virus-transformed tumor cells, and the effect of the most established antitumor agents, actinomycin D and doxorubicin, were investigated.\n\nMethods and ResultsDoxorubicin and actinomycin D differentially reduced RBM10 and RBM5 protein, respectively in both of HeLa and COS-7 cells. RBM10 protein was highly sensitive to doxorubicin in HeLa, COS-7 and A549 cells. In silico analysis revealed the several sumoylation sites of RBM10 and its sumoylated form could be targeted for the activated ubiquitin proteasome system. Actinomycin D affected the nuclear speckles localization of RBM10 and RBM5 in COS-7 and A549 lung carcinoma cells. Addition of actinomycin D in the culture medium and following culture for 34 hours promoted the prominent nuclear speckles of RBM10v2-GFP and RBM5. Hence, we explored the subnuclear localization of the full length RBM10v2 (852aa) and the amino terminally truncated forms and the responsible structural elements. The amino terminally truncated RBM10v2 [#486-852, #642-852], RBM10v2 [#648-852], RBM10v2 [#681-759, #681-852], and RBM10v2 [#660-852] retained the targeting elements for the nuclear speckles, nucleoplasm, nucleoli and whole nuclei, respectively.\n\nConclusionRBM10 is highly sensitive to doxorubicin. Actinomycin D affects the structural elements of RBM10 and promotes the nuclear speckles targeting. The C-terminal regions: RBM10v2 [#642-647], [#642-659], and [#660-680] play critical roles in the targeting to the subnuclear compartments. SIM and sumoylation sits of RBM10 and PML4 are important for molecular interaction of RBM10 and PML.

cell biology↗

bioRxiv2019

Molecular subtyping and prognostic assessment based on tumor mutation burden in patients with lung adenocarcinomas

Tumor mutation burden (TMB) is a potential biomarker for response to immunotherapy. The subset of patients with TMB has not been well characterized in lung adenocarcinomas. Here we performed molecular subtyping based on TMB and compared the features of different subtypes including clinical features, somatic driver genes and mutational signatures. We found that patients with lower tumor mutation burden had a longer disease-free survival, while higher tumor mutation burden is associated with smoking and aging. Analysis of somatic driver genes and mutational signatures demonstrates a significant association between somatic RYR2 mutations and the subtype with higher mutation burden. Overall, our study identified two molecular subtypes based on TMB and described the corresponding difference in their clinical and genomic levels.

genomics↗

bioRxiv2018

Enhancement of Macrophage Function by the Antimicrobial Peptide Sublancin Protects Mice from Methicillin-Resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is the major pathogen responsible for community and hospital bacterial infections. Sublancin, a glocosylated antimicrobial peptide isolated from Bacillus subtilis 168, possesses anti-bacterial infective effects. In this study, we investigated the role and anti-infection mechanism of sublancin in a mouse model of MRSA-induced sublethal infection. Sublancin could modulate innate immunity by inducing the production of IL-1{beta}, IL-6, TNF- and nitric oxide, enhancing phagocytosis and MRSA-killing activity in both RAW264.7 cells and peritoneal macrophages. The enhanced macrophage function by the peptide in vitro correlated with stronger protective activity in vivo in the MRSA-invasive sublethal infection model. Macrophages activation by sublancin was found to be mediated through the TLR4 and the NF-{kappa}B and MAPK signaling pathways. Moreover, oral administration of sublancin increased the frequencies of CD4+ and CD8+ T cells in mesenteric lymph nodes. The protective activity of sublancin was associated with in vivo augmenting phagocytotic activity of peritoneal macrophages and partly improving T cell-mediated immunity. Macrophages thus represent a potentially pivotal and novel target for future development of innate defense regulator therapeutics againt S. aureus infection.

immunology↗

bioRxiv2018

Association of Arg389Gly β1-adrenergic receptor polymorphism with effective dose of β blocker in congestive heart failure among Chinese Han population

BackgroundTo investigate the relationship between {beta}1-adrenergic receptor (ADRB1) gene polymorphisms and the response to medication in patients with congestive heart failure (CHF).\n\nMethods and ResultsTwo hundred and sixty patients with CHF were enrolled. Ser49Gly and Arg389Gly polymorphisms were identified. During one-year follow-up, differences of echocardiographic parameters and major adverse cardiac events (MACE) were analyzed. For Ser49Gly polymorphisms, there were no differences between AA genotype and AG/GG genotype of baseline clinical features and echocardiographic parameters as well as one-year incidence of MACE. For Arg389Gly polymorphisms, there were no significant differences in baseline clinical characteristics, LVDd and LVEF among the three genotypes. However, the increase amplitude of LVEF after one year among patients carrying GG genotype was significantly higher than those carrying CC genotype (11.7% vs 1.3%, P<0.05). The incidence of MACE among different genotypes of CC, CG and GG were 22.2%, 10.0% and 8.3%,with statistical difference (P=0.021).\n\nConclusionsThe study suggested there was no relationship between Ser49Gly polymorphisms of the ADRB1 gene and the therapeutic effect and prognosis in CHF patients under the same dosage of drugs. However, the improvement of cardiac function and prognosis in patients carrying the Gly389 allele were significantly better than those of Arg389Arg homozygous.

genetics↗