C-terminal fragment of human laminin-binding protein contains a receptor domain for Venezuelan equine encephalitis and tick-borne encephalitis viruses

Abstract

Polyclonal and monoclonal antibodies (MABs) to human laminin-binding protein (LBP) can efficiently block the penetration of some alpha- and flaviviruses into the cell. A panel of 13 types of MABs to human recombinant LBP was used for more detailed study of the mechanism of this process. Competitive analysis has shown that MABs to LBP can be divided into six different competition groups. MABs 4F6 and 8E4 classified under competition groups 3 and 4 can inhibit the replication of Venezuelan equine encephalitis virus (VEEV), which is indicative of their interaction with the receptor domain of LBP providing for binding with virions. According to enzyme immunoassay and immunoblotting data, polyclonal anti-idiotypic antibodies to MABs 4F6 and 8E4 modeling paratopes of the LBP receptor domain can specifically interact with VEEV E2 protein and tick-borne encephalitis virus (TBEV) E protein. Mapping of binding sites of MABs 4F6 and 8E4 with LBP by constructing short deletion fragments of the human LBP molecule has shown that MAB 8E4 interacts with the fragment of amino acid residues 187-210, and MAB 4F6 interacts with the fragment of residues 263-278 of LBP protein, which is represented by two TEDWS peptides separated by four amino acid residues. This suggested that the LBP receptor domain interacting with VEEV E2 and TBEV E viral proteins is located at the C-terminal fragment of the LBP molecule. A model of the spatial structure of the LBP receptor domain distally limited by four linear loops (two of which are represented by experimentally mapped regions of amino acid residues 187-210 and 263-278) as well as the central beta-folded region turning into the alpha-helical site including residues 200-216 of the LBP molecule and providing for the interaction with the laminin-1 molecule has been proposed.

The folded and disordered domains of human ribosomal protein SA have both idiosyncratic and shared functions as membrane receptors

“…The ED3 domain from YFV interacted mainly with the acid C-domain of RPSA whereas the ED3 domain from WNV interacted only with its N-domain. As regards alphaviruses, it has been reported that the C-domain of RPSA includes a binding site for VEEV and that its N-domain includes a binding site for SINV [9,26]. Therefore our results and previous data indicate that both N- and C-domains of RPSA could serve as viral receptors.…”

“…In particular, human RPSA is a potential cellular receptor for several flaviviruses, including DENV (dengue virus) and TBEV (tick-borne encephalitis virus) [19,20,24,25], and for several alphaviruses including VEEV (Venezualian equine encephalitis virus) and SINV (Sindbis virus) [9,18,26]. The envelope protein of flaviviruses includes three ectodomains, ED1, ED2 and ED3 and a transmembrane region.…”

Dynamics of Chikungunya Virus Cell Entry Unraveled by Single-Virus Tracking in Living Cells

“…Of these proteins, E2 is responsible for receptor binding and E1 facilitates the low-pH-dependent membrane fusion process (8,9). Multiple receptors that facilitate SFV, SINV, RRV, and VEEV cell entry have been identified, but none of these receptors appear to be crucial (10)(11)(12)(13)(14)(15)(16). The receptors identified act predominantly as attachment factors to capture the virus.…”

Force‐induced globule–coil transition in laminin binding protein and its role for viral–cell membrane fusion

“…Recombinant LBP has been produced and purified by metal‐chelate chromatography as discussed by us before (Sorokin et al ., ). mAbs to LBP and TBEV protein E have been produced as discussed by us before (Protopopova et al ., ; Malygin et al ., ). The Е 257–415 and E 1–254 polypeptides and protein E of TBEV were detected by means of the IEA with mAbs 10H10 against protein E of TBEV for capturing viral antigens on the surface of 96‐well polystyrene plates.…”

“…These demonstrations enabled us to propose and then to experimentally confirm the existence of an additional and different receptor region for the case of WNV protein E, the region located in the domain II of this protein and very close or identical to the location of the fusion peptide (Morozova et al ., ). Specificity of the corresponding interaction with LBP has been also confirmed by the mapping of an interaction site using a C‐end LBP fragment (Malygin et al ., ). Note that LBP is exploited as a cell receptor also by dengue, Sindbis and Venezuelan equine encephalitis viruses (Strauss et al ., ; Ludwig et al ., ; Bondarenko et al ., ).…”