ACE2 Can Act as the Secondary Receptor in the FcγR-Dependent ADE of SARS-CoV-2

2021 ◽  
Author(s):  
Zai Wang ◽  
Tingting Deng ◽  
Yulian Zhang ◽  
Wenquan Niu ◽  
Qiangqiang Nie ◽  
...  
Keyword(s):  
Secondary Receptor

Mechanisms of sensation

2019 ◽  
pp. 18-36
Author(s):  
Gordon L. Fain
Keyword(s):  
Sex Pheromone ◽  
Single Molecule ◽  
Sensory Transduction ◽  
Sensory Cells ◽  
Pheromone Detection ◽  
Receptor Cells ◽  
Physical Limit ◽  
Stimulus Detection ◽  
Secondary Receptor ◽  
Specialized Organization

“Mechanisms of sensation” is the second chapter of the book Sensory Transduction and describes general features of sensory cells, including types of sensory membrane, the specialized organization of membrane and protein within sensory cells, membrane renewal, external specializations of sense cells, mechanisms of stimulus detection, primary and secondary receptor cells, and receptor sensitivity and noise. These general features of sensory cells are illustrated by specific examples taken from a wide variety of organisms, from scallop and crayfish to Drosophila and vertebrates including mammals. The chapter concludes with a description of sex pheromone detection in the male moth, which achieves the physical limit of sensitivity of the receptor to a single molecule of attractant.

scholarly journals Phospholipids act as secondary receptor during the entry of the enveloped, double-stranded RNA bacteriophage φ6

2010 ◽  
Vol 91 (8) ◽  
pp. 2116-2120 ◽  
Author(s):  
Virginija Cvirkaitė-Krupovič ◽  
Minna M. Poranen ◽  
Dennis H. Bamford
Keyword(s):  
Pseudomonas Syringae ◽  
Cytoplasmic Membrane ◽  
Surface Protein ◽  
Gram Negative ◽  
Double Stranded Rna ◽  
Intracellular Vesicle ◽  
Head Groups ◽  
The Family ◽  
Secondary Receptor ◽  
Protein Rich

Bacteriophage φ6 is the type member of the family Cystoviridae and infects Gram-negative Pseudomonas syringae cells. The virion consists of a protein-rich lipid envelope enclosing a nucleocapsid. The nucleocapsid covers the icosahedral polymerase complex that encloses the double-stranded RNA genome. Here, we demonstrate that nucleocapsid surface protein P8 is the single nucleocapsid component interacting with the cytoplasmic membrane. This interaction takes place between P8 and phospholipid. Based on this and previous studies, we propose a model where the periplasmic nucleocapsid interacts with the phospholipid head groups and, when the membrane voltage exceeds the threshold of 110 mV, this interaction drives the nucleocapsid through the cytoplasmic membrane, resulting in an intracellular vesicle containing the nucleocapsid.

scholarly journals Turkey adenovirus 3, a siadenovirus, uses sialic acid on N-linked glycoproteins as a cellular receptor

2020 ◽  
Vol 101 (7) ◽  
pp. 760-771
Author(s):  
Hassan M. Mahsoub ◽  
Lijuan Yuan ◽  
F. William Pierson
Keyword(s):  
Sialic Acid ◽  
Virus Infection ◽  
Protein Molecule ◽  
Sialic Acids ◽  
Metabolic Inhibitors ◽  
Virus Infectivity ◽  
Membrane Glycoproteins ◽  
Virus Attachment ◽  
Immune Mediated ◽  
Secondary Receptor

Turkey adenovirus 3 (TAdV-3) is the causative agent of an immune-mediated disease in turkeys, haemorrhagic enteritis, through targeting B lymphocytes. In the present study, we investigated the role of sialic acid in TAdV-3 entry and characterized the structural components of TAdV-3 receptor(s) on RP19, B lymphoblastoid cells. Removal of the cell-surface sialic acids by neuraminidases or blocking of sialic acids by wheat germ agglutinin lectin reduced virus infection. Pre-incubation of cells with Maackia amurensis lectin or Sambucus nigra agglutinin resulted in virus reduction, suggesting that TAdV-3 uses both α2,3-linked and α2,6-linked sialic acids as attachment receptor. Virus infectivity data from RP19 cells treated with sodium periodate, proteases (trypsin or bromelain) or metabolic inhibitors (dl-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol, tunicamycin, or benzyl N-acetyl-α-d-galactosaminide) indicated that N-linked, but not O-linked, carbohydrates are part of the sialylated receptor and they are likely based on a membrane glycoprotein, rather than a glycolipid. Furthermore, our data, in conjunction with previous findings, implies that the secondary receptor for TAdV-3 is a protein molecule since the inhibition of glycolipid biosynthesis did not affect the virus infection, which was rather reduced by protease treatment. We can conclude that terminal sialic acids attached to N-linked membrane glycoproteins on B cells are used for virus attachment and are essential for successful virus infection.

Interactions between mouse ZP2 glycoprotein and proacrosin; a mechanism for secondary binding of sperm to the zona pellucida during fertilization

2001 ◽  
Vol 114 (22) ◽  
pp. 4127-4136
Author(s):  
Elizabeth Howes ◽  
John C. Pascall ◽  
Wolfgang Engel ◽  
Roy Jones
Keyword(s):  
Zona Pellucida ◽  
Solid Phase ◽  
Binding Assays ◽  
Vitro Fertilization ◽  
Sperm Binding ◽  
Secondary Receptor ◽  
Specificity Of Binding ◽  
Solid Phase Binding ◽  
Complementary Binding

The mouse zona pellucida glycoprotein, mZP2, is thought to be the secondary receptor on eggs for retention of acrosome-reacted sperm during fertilization. Here, we present evidence that one of its complementary binding proteins on sperm is proacrosin/acrosin. mZP2 binds to proacrosin null sperm considerably less effectively than to wild-type sperm. Binding is mediated by a strong ionic interaction between polysulphate groups on mZP2 and basic residues on an internal proacrosin peptide. The stereochemistry of both sulphate groups and basic amino acids determines the specificity of binding. Structurally relevant sulphated polymers and suramin, a polysulphonated anticancer drug, compete with mZP2 for complementary binding sites on proacrosin/acrosin in solid-phase binding assays. The same competitors also displace attached sperm from the zona pellucida of eggs in an in vitro fertilization system. This combination of genetic, biochemical and functional data supports the hypothesis that mZP2-proacrosin interactions are important for retention of acrosome-reacted sperm on the egg surface during fertilization. Safe mimetics of suramin have potential as non-steroidal antifertility agents.

scholarly journals Novel Host Recognition Mechanism of the K1 Capsule-Specific Phage of Escherichia coli : Capsular Polysaccharide as the First Receptor and Lipopolysaccharide as the Secondary Receptor

2021 ◽  
Author(s):  
Qianwen Gong ◽  
Xuhang Wang ◽  
Haosheng Huang ◽  
Yu Sun ◽  
Xinjie Qian ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Capsular Polysaccharide ◽  
Host Recognition ◽  
Fluorescence Labeling ◽  
E Coli ◽  
Specific Phage ◽  
Secondary Receptor ◽  
New Type ◽  
Tail Protein ◽  
K1 Capsule

K1 capsule-specific phages of Escherichia coli have been reported in recent years, but the molecular mechanism involved in host recognition of these phages remains unknown. In this study, the interactions between PNJ1809-36, a new K1-specific phage and its host bacteria E. coli DE058, were investigated. A transposon mutation library was used to screen for receptor-related genes. Gene deletion, lysis curve determination, plaque formation test, adsorption assay and inhibition assay of phage by lipopolysaccharide (LPS) showed that capsular polysaccharide (CPS) was the first receptor for the initial adsorption of PNJ1809-36 to E. coli DE058 and LPS was a secondary receptor for the irreversible binding of the phage. The penultimate galactose in the outer core was identified as the specific binding region on LPS. Through antibody blocking assay, fluorescence labeling and high-performance gel permeation chromatography (HPGPC), the tail protein ORF261 of phage PNJ1809-36 was identified as the receptor binding protein on CPS. Given these findings, we propose a model for the recognition process of phage PNJ1809-36 on E. coli DE058: The phage PNJ1809-36 tail protein ORF261 recognizes and adsorbs to the K1 capsule; then the K1 capsule is partially degraded, exposing the active site of LPS which is recognized by phage PNJ1809-36. This model provides insight into the molecular mechanisms between K1-specific phages and their host bacteria. IMPORTANCE It has been speculated that CPS is the main receptor of K1-specific phages belonging to Siphoviridae . In recent years, a new type of K1-specific phage belonging to Myoviridae has been reported, but its host recognition mechanisms remain unknown. Here, we studied the interactions between PNJ1809-36, a new type of K1 phage, and its host bacteria E. coli DE058. Our research showed that the phage initially adsorbed to the K1 capsule mediated by ORF261 and then bound to the penultimate galactose of LPS to begin the infection process.

scholarly journals A Human Papillomavirus (HPV)In VitroNeutralization Assay That Recapitulates theIn VitroProcess of Infection Provides a Sensitive Measure of HPV L2 Infection-Inhibiting Antibodies

2012 ◽  
Vol 19 (7) ◽  
pp. 1075-1082 ◽  
Author(s):  
Patricia M. Day ◽  
Yuk-Ying S. Pang ◽  
Rhonda C. Kines ◽  
Cynthia D. Thompson ◽  
Douglas R. Lowy ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Neutralizing Antibodies ◽  
Neutralization Assay ◽  
Immune Serum ◽  
Human Papillomavirus Type 16 ◽  
Secondary Receptor ◽  
Timing Of Exposure ◽  
Experimental Challenge

ABSTRACTPapillomavirus L2-based vaccines have generally induced low-level or undetectable neutralizing antibodies in standardin vitroassays yet typically protect well againstin vivoexperimental challenge in animal models. Herein we document that mice vaccinated with an L2 vaccine comprising a fusion protein of the L2 amino acids 11 to 88 of human papillomavirus type 16 (HPV16), HPV18, HPV1, HPV5, and HPV6 were uniformly protected from cervicovaginal challenge with HPV16 pseudovirus, but neutralizing antibodies against HPV16, -31, -33, -45, or -58 were rarely detected in their sera using a standardin vitroneutralization assay. To address this discrepancy, we developed a neutralization assay based on anin vitroinfectivity mechanism that more closely mimics thein vivoinfectious process, specifically by spaciotemporally separating primary and secondary receptor engagement and correspondingly by altering the timing of exposure of the dominant L2 cross-neutralizing epitopes to the antibodies. With the new assay, titers in the 100 to 10,000 range were measured for most sera, whereas undetectable neutralizing activities were observed with the standard assay.In vitroneutralizing titers measured in the serum of mice after passive transfer of rabbit L2 immune serum correlated with protection from cervicovaginal challenge of the mice. This “L2-based”in vitroneutralization assay should prove useful in critically evaluating the immunogenicity of L2 vaccine candidates in preclinical studies and future clinical trials.

scholarly journals Loss of a pyoverdine secondary receptor in Pseudomonas aeruginosa results in a fitter strain suitable for population invasion

2020 ◽  
Author(s):  
Jaime González ◽  
Manuel Salvador ◽  
Özhan Özkaya ◽  
Matt Spick ◽  
Kate Reid ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Secondary Receptor
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