Receptor recognition and cell entry by viruses are two initial and essential steps in viral infection cycles. They are important determinants of viral host ranges, tissue tropisms and pathogenesis, and are primary targets for human intervention. Coronaviruses (CoVs) pose serious health threats to humans and other animals. SARS-CoV and MERS-CoV have infected thousands of people with significant fatality, whereas porcine epidemic diarrhea CoV is currently causing ~100% fatality in piglets. A virus-surface spike protein guides CoV entry into host cells by binding to its host receptor via its S1 subunit and fusing viral and host membranes via its S2 subunit. S1 from different CoVs recognizes a variety of host receptors through one or both of its domains (S1-NTD and S1-CTD), and the S1/S2 boundary is cleaved by host proteases for activation of membrane fusion by S2. Our previous research has determined a number of crystal structures of CoV S1 domains by themselves or in complex with their respective receptor, and also shown how proteolysis regulates the cell entry of some CoVs. Our research has contributed critically to the current knowledge about the molecular mechanisms for CoV receptor recognition, cell entry, and cross-species transmission. In this competitive renewal of R01, we will continue to investigate how CoVs exploit host receptors and host proteases for cell entry. This proposal has three specific aims.
Aim 1 examines receptor binding by CoV S1-NTDs. Specifically, we will investigate whether S1-NTDs from different CoV genera have the same structural fold and evolutionary origin as host galectins (galactose-binding lectins). We will also examine how CoV S1-NTDs recognize sugar receptors. These studies will reveal the evolutionary origins of CoV S1-NTDs, enhance understanding of sugar recognition by CoVs, and may facilitate future design of sugar analogues and subunit vaccines to inhibit CoV infections.
Aim 2 focuses on receptor binding by CoV S1-CTDs. Specifically, we will analyze the interactions between the S1-CTDs of bat SARS-like CoVs (SL-CoVs) and the protein receptor homologues from humans and other animals, and elucidate how bat SL-CoVs transmitted to humans and other animals to cause the SARS epidemic through evolutionary changes in their S1-CTDs. These studies will provide critical information for understanding emergence potential of bat SL-CoVs and for facilitating epidemic monitoring and control.
Aim 3 investigates cell entry by CoVs. Specifically, we will investigate what host proteases activate CoV entry and how the proteases motifs in CoV spikes have evolved to modulate CoV entry. These studies will reveal how host proteases regulate CoV entry to meet their specific need for host range, tissue tropism and pathogenesis, and may facilitate future design of protease inhibitors to block CoV entry. Overall, this proposal investigates the molecular and structural mechanisms for receptor recognition, cell entry, cross-species transmission, and tissue tropism of CoVs, which will lead to novel principles in virology. This research is also important for evaluating the emerging disease potentials of CoVs and for preventing, controlling and treating CoV infections in humans and other animals.

Public Health Relevance

This research investigates the molecular and structural mechanisms for the receptor recognition and cell entry of coronaviruses. It explores novel principles governing viral evolution, receptor recognition, cell entry, host ranges, cross-species infections, and tissue tropisms. These studies are critical for evaluating the emerging disease potentials of coronaviruses and for preventing, controlling and treating the spread of coronaviruses in humans or other animals.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
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Virology - A Study Section (VIRA)
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Stemmy, Erik J
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University of Minnesota Twin Cities
Schools of Medicine
United States
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Luo, Chu-Ming; Wang, Ning; Yang, Xing-Lou et al. (2018) Discovery of Novel Bat Coronaviruses in South China That Use the Same Receptor as Middle East Respiratory Syndrome Coronavirus. J Virol 92:
Gunaratne, Gihan S; Yang, Yang; Li, Fang et al. (2018) NAADP-dependent Ca2+ signaling regulates Middle East respiratory syndrome-coronavirus pseudovirus translocation through the endolysosomal system. Cell Calcium 75:30-41
Zheng, Yuan; Shang, Jian; Yang, Yang et al. (2018) Lysosomal Proteases Are a Determinant of Coronavirus Tropism. J Virol 92:
Shang, Jian; Zheng, Yuan; Yang, Yang et al. (2018) Cryo-Electron Microscopy Structure of Porcine Deltacoronavirus Spike Protein in the Prefusion State J Virol 92:
Zhao, Guangyu; He, Lei; Sun, Shihui et al. (2018) A Novel Nanobody Targeting Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Receptor-Binding Domain Has Potent Cross-Neutralizing Activity and Protective Efficacy against MERS-CoV. J Virol 92:
Douglas, Madeline G; Kocher, Jacob F; Scobey, Trevor et al. (2018) Adaptive evolution influences the infectious dose of MERS-CoV necessary to achieve severe respiratory disease. Virology 517:98-107
Du, Lanying; Yang, Yang; Zhou, Yusen et al. (2017) MERS-CoV spike protein: a key target for antivirals. Expert Opin Ther Targets 21:131-143
Peng, Guiqing; Yang, Yang; Pasquarella, Joseph R et al. (2017) Structural and Molecular Evidence Suggesting Coronavirus-driven Evolution of Mouse Receptor. J Biol Chem 292:2174-2181
Hou, Yixuan; Lin, Chun-Ming; Yokoyama, Masaru et al. (2017) Deletion of a 197-Amino-Acid Region in the N-Terminal Domain of Spike Protein Attenuates Porcine Epidemic Diarrhea Virus in Piglets. J Virol 91:
Joshi, Shilvi; Chen, Lang; Winter, Michael B et al. (2017) The Rational Design of Therapeutic Peptides for Aminopeptidase N using a Substrate-Based Approach. Sci Rep 7:1424

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