scholarly journals Characterization of the Interaction of Lassa Fever Virus with Its Cellular Receptor α-Dystroglycan

2005 ◽  
Vol 79 (10) ◽  
pp. 5979-5987 ◽  
Author(s):  
Stefan Kunz ◽  
Jillian M. Rojek ◽  
Mar Perez ◽  
Christina F. Spiropoulou ◽  
Michael B. A. Oldstone

ABSTRACT The cellular receptor for the Old World arenaviruses Lassa fever virus (LFV) and lymphocytic choriomeningitis virus (LCMV) has recently been identified as α-dystroglycan (α-DG), a cell surface receptor that provides a molecular link between the extracellular matrix and the actin-based cytoskeleton. In the present study, we show that LFV binds to α-DG with high affinity in the low-nanomolar range. Recombinant vesicular stomatitis virus pseudotyped with LFV glycoprotein (GP) adopted the receptor binding characteristics of LFV and depended on α-DG for infection of cells. Mapping of the binding site of LFV on α-DG revealed that LFV binding required the same domains of α-DG that are involved in the binding of LCMV. Further, LFV was found to efficiently compete with laminin α1 and α2 chains for α-DG binding. Together with our previous studies on receptor binding of the prototypic immunosuppressive LCMV isolate LCMV clone 13, these findings indicate a high degree of conservation in the receptor binding characteristics between the highly human-pathogenic LFV and murine-immunosuppressive LCMV isolates.

2005 ◽  
Vol 79 (22) ◽  
pp. 14282-14296 ◽  
Author(s):  
Stefan Kunz ◽  
Jillian M. Rojek ◽  
Motoi Kanagawa ◽  
Christina F. Spiropoulou ◽  
Rita Barresi ◽  
...  

ABSTRACT The receptor for lymphocytic choriomeningitis virus (LCMV), the human pathogenic Lassa fever virus (LFV), and clade C New World arenaviruses is α-dystroglycan (α-DG), a cell surface receptor for proteins of the extracellular matrix (ECM). Specific posttranslational modification of α-DG by the glycosyltransferase LARGE is critical for its function as an ECM receptor. In the present study, we show that LARGE-dependent modification is also crucial for α-DG's function as a cellular receptor for arenaviruses. Virus binding involves the mucin-type domain of α-DG and depends on modification by LARGE. A crucial role of the LARGE-dependent glycosylation of α-DG for virus binding is found for several isolates of LCMV, LFV, and the arenaviruses Mobala and Oliveros. Since the posttranslational modification by LARGE is crucial for α-DG recognition by both arenaviruses and the host-derived ligand laminin, it also influences competition between virus and laminin for α-DG. Hence, LARGE-dependent glycosylation of α-DG has important implications for the virus-host cell interaction and the pathogenesis of LFV in humans.


2002 ◽  
Vol 70 (7) ◽  
pp. 3427-3432 ◽  
Author(s):  
Takeshi Matsuzawa ◽  
Takashige Kashimoto ◽  
Jun Katahira ◽  
Yasuhiko Horiguchi

ABSTRACT Bordetella dermonecrotic toxin (DNT) stimulates the assembly of actin stress fibers and focal adhesions by deamidating or polyaminating Gln63 of the small GTPase Rho. DNT is an A-B toxin which is composed of an N-terminal receptor-binding (B) domain and a C-terminal enzymatically active (A) domain. In this study, to analyze the functional and structural organization of DNT, we prepared 10 clones of hybridoma producing anti-DNT monoclonal antibodies. One of these antibodies, 2B3, neutralized the effects of DNT on target cells when mixed with the toxin. When microinjected into cells, however, 2B3 did not inhibit the intoxication by DNT. Western blot analysis revealed that 2B3 recognized the N-terminal region of DNT. To delineate the DNT-binding domain, we examined a series of truncated DNT mutants for the ability to competitively inhibit the intoxication of cells by the full-length DNT and found that a fragment consisting of the N-terminal 54 amino acids (DNT1-54) was the smallest inhibitory fragment. The radioiodinated DNT1-54 actually bound to target cells, which was inhibited by 2B3. These results suggest that the N-terminal 54 amino acids of DNT are responsible for the binding to target cells. DNT1-54 bound to none of the DNT-resistant cells, implying the presence of a cell surface receptor specific to DNT-sensitive cells.


2002 ◽  
Vol 362 (2) ◽  
pp. 265-271 ◽  
Author(s):  
Manickavasagam SUNDARAM ◽  
Daan M. F. van AALTEN ◽  
John B. C. FINDLAY ◽  
Asipu SIVAPRASADARAO

Members of the lipocalin superfamily share a common structural fold, but differ from each other with respect to the molecules with which they interact. They all contain eight β-strands (A—H) that fold to form a well-defined β-barrel, which harbours a binding pocket for hydrophobic ligands. These strands are connected by loops that vary in size and structure and make up the closed and open ends of the pocket. In addition to binding ligands, some members of the family interact with other macromolecules, the specificity of which is thought to be associated with the variable loop regions. Here, we have investigated whether the macromolecular-recognition properties can be transferred from one member of the family to another. For this, we chose the prototypical lipocalin, the plasma retinol-binding protein (RBP) and its close structural homologue the epididymal retinoic acid-binding protein (ERABP). RBP exhibits three molecular-recognition properties: it binds to retinol, to transthyretin (TTR) and to a cell-surface receptor. ERABP binds retinoic acid, but whether it interacts with other macromolecules is not known. Here, we show that ERABP does not bind to TTR and the RBP receptor, but when the loops of RBP near the open end of the pocket (L-1, L-2 and L-3, connecting β-strands A—B, C—D and E—F, respectively) were substituted into the corresponding regions of ERABP, the resulting chimaera acquired the ability to bind TTR and the receptor. L-2 and L-3 were found to be the major determinants of the receptor- and TTR-binding specificities respectively. Thus we demonstrate that lipocalins serve as excellent scaffolds for engineering novel biological functions.


2021 ◽  
Author(s):  
Amine Driouchi ◽  
Scott Gray-Owen ◽  
Christopher M Yip

Mapping the self-organization and spatial distribution of membrane proteins is key to understanding their function. We report here on a correlated STORM/homoFRET imaging approach for resolving the nanoscale distribution and oligomeric state of membrane proteins. Live cell homoFRET imaging of CEACAM1, a cell-surface receptor known to exist in a complex equilibrium between monomer and dimer/oligomer states, revealed highly heterogenous diffraction-limited structures on the surface of HeLa cells. Correlated super-resolved STORM imaging revealed that these structures comprised a complex mixture and spatial distribution of self-associated CEACAM1 molecules. This correlated approach provides a compelling strategy for addressing challenging questions about the interplay between membrane protein concentration, distribution, interaction, clustering, and function.


2006 ◽  
Vol 14 (7S_Part_27) ◽  
pp. P1453-P1454
Author(s):  
Nicola J. Corbett ◽  
Kate Fisher ◽  
Helen A. Rowland ◽  
Alys C. Jones ◽  
Nigel M. Hooper

2008 ◽  
Vol 76 (7) ◽  
pp. 2862-2871 ◽  
Author(s):  
Xi Na ◽  
Ho Kim ◽  
Mary P. Moyer ◽  
Charalabos Pothoulakis ◽  
J. Thomas LaMont

ABSTRACT Clostridium difficile toxin A (TxA), a key mediator of antibiotic-associated colitis, requires binding to a cell surface receptor prior to internalization. Our aim was to identify novel plasma membrane TxA binding proteins on human colonocytes. TxA was coupled with biotin and cross-linked to the surface of HT29 human colonic epithelial cells. The main colonocyte binding protein for TxA was identified as glycoprotein 96 (gp96) by coimmunoprecipitation and mass spectrum analysis. gp96 is a member of the heat shock protein family, which is expressed on human colonocyte apical membranes as well as in the cytoplasm. TxA binding to gp96 was confirmed by fluorescence immunostaining and in vitro coimmunoprecipitation. Following TxA binding, the TxA-gp96 complex was translocated from the cell membrane to the cytoplasm. Pretreatment with gp96 antibody decreased TxA binding to colonocytes and inhibited TxA-induced cell rounding. Small interfering RNA directed against gp96 reduced gp96 expression and cytotoxicity in colonocytes. TxA-induced inflammatory signaling via p38 and apoptosis as measured by activation of BAK (Bcl-2 homologous antagonist/killer) and DNA fragmentation were decreased in gp96-deficient B cells. We conclude that human colonocyte gp96 serves as a plasma membrane binding protein that enhances cellular entry of TxA, participates in cellular signaling events in the inflammatory cascade, and facilitates cytotoxicity.


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