Phosphatidylserine Is Not the Cell Surface Receptor for Vesicular Stomatitis Virus

ABSTRACT The envelope protein from vesicular stomatitis virus (VSV) has become an important tool for gene transfer and gene therapy. It is widely used mainly because of its ability to mediate virus entry into all cell types tested to date. Consistent with the broad tropism of the virus, the receptor for VSV is thought to be a ubiquitous membrane lipid, phosphatidylserine (PS). However, the evidence for this hypothesis is indirect and incomplete. Here, we have examined the potential interaction of VSV and PS at the plasma membrane in more detail. Measurements of cell surface levels of PS show a wide range across cell types from different organisms. We demonstrate that there is no correlation between the cell surface PS levels and VSV infection or binding. We also demonstrate that an excess of annexin V, which binds specifically and tightly to PS, does not inhibit infection or binding by VSV. While the addition of PS to cells does allow increased virus entry, we show that this effect is not specific to the VSV envelope. We conclude that PS is not the cell surface receptor for VSV, although it may be involved in a postbinding step of virus entry.

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230. Megalin, RAP and Nkx3.1 expression in the developing reproductive tract of a marsupial, the tammar wallaby

Reproduction Fertility and Development ◽

10.1071/srb08abs230 ◽

2008 ◽

Vol 20 (9) ◽

pp. 30

Author(s):

M. Gamat ◽

M. B. Renfree ◽

A. J. Pask ◽

G. Shaw

Keyword(s):

Cell Surface ◽

Reproductive Tract ◽

Tammar Wallaby ◽

Cell Surface Receptor ◽

Urogenital Sinus ◽

Receptor Associated Protein ◽

Wide Range ◽

Surface Receptor ◽

A Cell ◽

Strong Staining

Androgens induce the differentiation of the urogenital sinus (UGS) to form a prostate. An early marker of this response is upregulation of the transcription factor Nkx3.1 in the urogenital epithelium in the precursors of prostatic buds. In tammars, prostate differentiation begins ~3 weeks after birth and after the time the testis starts to secrete androgens, and 2 weeks after androgen stimulated Wolffian duct differentiation. The reason for this delay in prostate differentiation is unexplained. Androgen receptors are present in the UGS, and the potent androgen, androstanediol, induces prostatic development in females. Whilst androgens may diffuse into cells by across the cell membrane, there is increasing evidence that steroids are also internalised actively via the cell-surface transport molecule Megalin. We are exploring the possibility that the delay may be related to the establishment of a Megalin-mediated pathway. Megalin is a cell surface receptor expressed on epithelia and mediates the endocytosis of a wide range of ligands, including SHBG-bound sex steroids. Megalin action is regulated by Receptor Associated Protein (RAP), which acts as an antagonist to Megalin action. This study cloned partial sequences of Megalin, RAP and Nkx3.1 and examined their expression in the developing urogenital sinus of the tammar wallaby using RT–PCR. The cellular distribution of Megalin protein in the developing UGS was examined using immunohistochemistry. Megalin, RAP and Nkx3.1 in the tammar were all highly conserved with eutherian orthologueues. Megalin and Nkx3.1 transcripts were detected in the liver, kidney, ovary, testis and developing urogenital sinus of male and female tammars. In the developing UGS of the tammar, there was strong staining for Megalin protein in the urogenital epithelium with some diffuse staining in the surrounding mesenchyme. Together, these results suggest that Megalin could be a key gene in the mediation of androgen action in prostatic development in the tammar wallaby.

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Monitoring Viral Entry in Real-Time Using a Luciferase Recombinant Vesicular Stomatitis Virus Producing SARS-CoV-2, EBOV, LASV, CHIKV, and VSV Glycoproteins

Viruses ◽

10.3390/v12121457 ◽

2020 ◽

Vol 12 (12) ◽

pp. 1457

Author(s):

Maria Fernanda Lay Mendoza ◽

Marissa Danielle Acciani ◽

Courtney Nina Levit ◽

Christopher Santa Maria ◽

Melinda Ann Brindley

Keyword(s):

Real Time ◽

Vesicular Stomatitis Virus ◽

Viral Entry ◽

Cell Surface Receptor ◽

Enveloped Virus ◽

Glycoprotein G ◽

Viral Glycoproteins ◽

Surface Receptor ◽

Vesicular Stomatitis ◽

Time Required

Viral entry is the first stage in the virus replication cycle and, for enveloped viruses, is mediated by virally encoded glycoproteins. Viral glycoproteins have different receptor affinities and triggering mechanisms. We employed vesicular stomatitis virus (VSV), a BSL-2 enveloped virus that can incorporate non-native glycoproteins, to examine the entry efficiencies of diverse viral glycoproteins. To compare the glycoprotein-mediated entry efficiencies of VSV glycoprotein (G), Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S), Ebola (EBOV) glycoprotein (GP), Lassa (LASV) GP, and Chikungunya (CHIKV) envelope (E) protein, we produced recombinant VSV (rVSV) viruses that produce the five glycoproteins. The rVSV virions encoded a nano luciferase (NLucP) reporter gene fused to a destabilization domain (PEST), which we used in combination with the live-cell substrate EndurazineTM to monitor viral entry kinetics in real time. Our data indicate that rVSV particles with glycoproteins that require more post-internalization priming typically demonstrate delayed entry in comparison to VSV G. In addition to determining the time required for each virus to complete entry, we also used our system to evaluate viral cell surface receptor preferences, monitor fusion, and elucidate endocytosis mechanisms. This system can be rapidly employed to examine diverse viral glycoproteins and their entry requirements.

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Thranbospondin Promotes Cell-and Platelet-Substratum Adhesion

10.1055/s-0038-1643820 ◽

1987 ◽

Author(s):

George P Tuszynski ◽

Vicki L Rothman ◽

Andrew Murphy ◽

Katherine Siegler ◽

Linda Smith ◽

...

Keyword(s):

Cell Adhesion ◽

Cell Surface ◽

Polyacrylamide Gel Electrophoresis ◽

Cell Types ◽

Preliminary Evidence ◽

Human Platelets ◽

Cell Surface Receptor ◽

Binding Assays ◽

Surface Receptor

Thrombospondin (TSP), isolated from human platelets, promotes the in vitro, calcium-specific adhesion of a variety of cells, including platelets, melanoma cells, muscle cells, endothelial cells, fibroblasts, and epithelial cells. The cell adhesion-promoting activity of TSP is species independent since human, bovine, pig, rat and mouse cells all adhered to TSP. Furthermore, the cell adhesion-promoting activity of TSP is specific and not due to a nonspecific protein effect or to contamination by fibronectin, vitronectin, or laminin. That is, neither bovine serum albumin nor TSP preparations treated with a monospecific anti-TSP antibody support cell adhesion. As analyzed by polyacrylamide-gel electrophoresis and specific antibody binding assays, the TSP preparations used in these studies contained no detectable fibronectin or laminin and less than 0.04% vitronectin. The cell surface receptor for TSP appears distinct frcm that of fibronectin since an antiserum that blocks cell adhesion to fibronectin has no effect on adhesion to TSP. In addition, The platelet cell surface receptor for TSP appears distinct, frcm that of fibrinogen since thrcmbasthenic platelets adhere to TSP as well as control platelets. Antibodies to the GPIIb-GPIIIa complex block platelet adhesion to fibrinogen but have no effect on adhesion to TSP. Initial characterization of the cell surface receptor for TSP shows it to be protein in nature since cells treated with trypsin fail to adhere to TSP. In summary, our results provide the first clear evidence that TSP specifically promotes cell-substratum adhesion of a variety of cell types independent of the animal species. Our preliminary evidence suggests that the cell-surface receptor(s) for TSP is protein and that it is distinct for the receptor for fibronectin and fibrinogen. Our data suggest that TSP may play a central role in normal adhesive events mediated by platelets and other cells, such as those involved in hemostasis and wound healing. In addition, TSP may be involved in pathological adhesive events mediated by platelets and tumor cells, such as those involved in cardiovascular disease and tumor cell metastasis.

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Isolation of an adhesion-mediating protein from chick neural retina adherons.

The Journal of Cell Biology ◽

10.1083/jcb.101.3.1071 ◽

1985 ◽

Vol 101 (3) ◽

pp. 1071-1077 ◽

Cited By ~ 42

Author(s):

D Schubert ◽

M LaCorbiere

Keyword(s):

Cell Surface ◽

Heparan Sulfate ◽

Cultured Cells ◽

Cell Types ◽

Neural Retina ◽

Cell Surface Receptor ◽

Isolation And Characterization ◽

Surface Receptor ◽

Adhesive Interactions

Adherons are high molecular weight glycoprotein complexes which are released into the growth medium of cultured cells. They mediate the adhesive interactions of many cell types, including those of embryonic chick neural retina. The cell surface receptor for chick neural retina adherons has been purified, and shown to be a heparan sulfate proteoglycan (Schubert, D., and M. LaCorbiere, 1985, J. Cell Biol., 100:56-63). This paper describes the isolation and characterization of a protein in neural retina adherons which interacts specifically with the cell surface receptor. The 20,000-mol-wt protein, called retinal purpurin (RP), stimulates neural retina cell-substratum adhesion and prolongs the survival of neural retina cells in culture. The RP protein interacts with heparin and heparan sulfate, but not with other glycosaminoglycans. Monovalent antibodies against RP inhibit RP-cell adhesion as well as adheron-cell interactions. The RP protein is found in neural retina, but not in other tissues such as brain and muscle. These data suggest that RP plays a role in both the survival and adhesive interactions of neural retina cells.

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SPaRTAN, a computational framework for linking cell-surface receptors to transcriptional regulators

Nucleic Acids Research ◽

10.1093/nar/gkab745 ◽

2021 ◽

Vol 49 (17) ◽

pp. 9633-9647

Author(s):

Xiaojun Ma ◽

Ashwin Somasundaram ◽

Zengbiao Qi ◽

Douglas J Hartman ◽

Harinder Singh ◽

...

Keyword(s):

Cell Surface ◽

Single Cell ◽

Transcriptional Regulators ◽

Cell Types ◽

Receptor Expression ◽

Cell Surface Receptor ◽

Cell Surface Receptors ◽

Surface Receptors ◽

Surface Receptor ◽

Context Specific

Abstract The identity and functions of specialized cell types are dependent on the complex interplay between signaling and transcriptional networks. Recently single-cell technologies have been developed that enable simultaneous quantitative analysis of cell-surface receptor expression with transcriptional states. To date, these datasets have not been used to systematically develop cell-context-specific maps of the interface between signaling and transcriptional regulators orchestrating cellular identity and function. We present SPaRTAN (Single-cell Proteomic and RNA based Transcription factor Activity Network), a computational method to link cell-surface receptors to transcription factors (TFs) by exploiting cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) datasets with cis-regulatory information. SPaRTAN is applied to immune cell types in the blood to predict the coupling of signaling receptors with cell context-specific TFs. Selected predictions are validated by prior knowledge and flow cytometry analyses. SPaRTAN is then used to predict the signaling coupled TF states of tumor infiltrating CD8+ T cells in malignant peritoneal and pleural mesotheliomas. SPaRTAN enhances the utility of CITE-seq datasets to uncover TF and cell-surface receptor relationships in diverse cellular states.

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Monitoring Viral Entry in Real-Time Using a Luciferase Recombinant Vesicular Stomatitis Virus Producing SARS-CoV-2, EBOV, LASV, CHIKV, and VSV Glycoproteins

10.20944/preprints202011.0641.v1 ◽

2020 ◽

Author(s):

Maria Fernanda Lay Mendoza ◽

Marissa Danielle Acciani ◽

Courtney Nina Levit ◽

Christopher Santa Maria ◽

Melinda Ann Brindley

Keyword(s):

Real Time ◽

Vesicular Stomatitis Virus ◽

Viral Entry ◽

Cell Surface Receptor ◽

Enveloped Virus ◽

Viral Glycoproteins ◽

Surface Receptor ◽

Entry Requirements ◽

Vesicular Stomatitis ◽

Time Required

Viral entry is the first stage in the virus replication cycle and, for enveloped viruses, is mediated by virally encoded glycoproteins. Viral glycoproteins have different receptor affinities and triggering mechanisms. We employed vesicular stomatitis virus (VSV), a BSL-2 enveloped virus that can incorporate non-native glycoproteins, to examine the entry efficiencies of diverse viral glycoproteins. To compare glycoprotein-mediated entry efficiencies of: VSV G, SARS-CoV-2 S, EBOV GP, LASV GP, and CHIKV E we produced recombinant VSV (rVSV) viruses that produce the five glycoproteins. The rVSV virions encoded a nano luciferase-PEST (NLucP) reporter gene, which we used in combination with the live-cell substrate Endurazine™ to monitor viral entry kinetics in real time. Our data indicate that rVSV particles with glycoproteins that require more post-internalization priming typically demonstrate delayed entry in comparison to VSV G. In addition to determining the time required for each virus to complete entry, we also used our system to evaluate viral cell surface receptor preferences, monitor fusion, and elucidate endocytosis mechanisms. This system can be rapidly employed to examine diverse viral glycoproteins and their entry requirements.

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The molecular circuit of steroid signalling in plants

Essays in Biochemistry ◽

10.1042/bse0580071 ◽

2015 ◽

Vol 58 ◽

pp. 71-82 ◽

Cited By ~ 4

Author(s):

Thomas Hartwig ◽

Zhi-Yong Wang

Keyword(s):

Cell Surface ◽

Steroid Hormones ◽

Signal Transduction Pathway ◽

Nuclear Gene ◽

Cell Surface Receptor ◽

Receptor Kinase ◽

Environmental Signals ◽

Nuclear Gene Expression ◽

Wide Range ◽

Surface Receptor

Steroid hormones are key regulators of growth and physiology in both plants and animals. The plant steroid hormones known as brassinosteroids (BRs) are essential for a wide range of developmental processes throughout the life cycle. In contrast with animal steroid hormones, which act mostly through nuclear receptors, BRs act through a cell-surface receptor kinase. The BR signal transduction pathway from the cell-surface receptor to nuclear gene expression has been elucidated in great molecular detail, and thus serves as a paradigm for receptor kinase signalling in plants. Furthermore, several mechanisms of signal integration have been identified that explain how BRs and other hormonal and environmental signals co-regulate specific developmental outputs in a synergistic or antagonistic manner.

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Clostridium perfringens Iota Toxin: Binding Studies and Characterization of Cell Surface Receptor by Fluorescence-Activated Cytometry

Infection and Immunity ◽

10.1128/iai.68.6.3475-3484.2000 ◽

2000 ◽

Vol 68 (6) ◽

pp. 3475-3484 ◽

Cited By ~ 44

Author(s):

Bradley G. Stiles ◽

Martha L. Hale ◽

Jean-Christophe Marvaud ◽

Michel R. Popoff

Keyword(s):

Cell Surface ◽

Clostridium Perfringens ◽

Cell Types ◽

Vero Cells ◽

Cell Surface Receptor ◽

Binding Studies ◽

Binding Characteristics ◽

Toxin Binding ◽

Surface Receptor ◽

Clostridium Perfringens Iota Toxin

ABSTRACT The binding characteristics of iota toxin, a binary enterotoxin produced by Clostridium perfringens type E, were studied by fluorescence-activated cytometry. The proteolytically activated binding component of iota toxin, iota b (Ib), bound to various cell types when incubated at 4, 25, or 37°C for 10 min. The binding of Ib was inhibited by antisera against C. perfringens type E orClostridium spiroforme culture supernatants, but notC. perfringens types C or D. Pretreatment of Vero cells with glycosidases or lectins did not affect Ib interactions, while pronase effectively prevented Ib binding to the cell surface. The Ib protomer (Ibp) bound to the cell surface, but trypsinization of Ibp was necessary for docking of the ADP-ribosylating component, iota a (Ia). Ia attached to cell-bound Ib within 10 min at 37°C, but surface levels of Ia decreased 90% after 30 min and were undetectable by 60 min. Detectable surface levels of Ib also diminished over time, and Western blot analysis suggested internalization or embedment of Ib into the membrane.

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