An actin-binding protein is involved in pestivirus entry into bovine cells

Infection of bovine cells with bovine viral diarrhoea virus (BVDV) can be b locked by the monoclonal antibody (mab) BVD/CA 26, which is directed agains t a cellular membrane protein. To characterize this molecule, it was isolat ed and purified by column chromatography. It was found to be an acidic, gly cosylated membrane protein consisting of two polypeptide chains of about 28 and 56 kDa. Under non-reducing conditions the chains formed multimers of a bout 200 kDa. In an actin binding assay the 56 kDa polypeptide chain bound to F-actin as judged by co-sedimentation with actin filaments. Since the ta rget molecule of BVD/CA 26 is localized on the surface of living cells and additionally binds to F-actin, a possible biological function may be to con nect the cortical actin filaments with the cellular plasma membrane. The bl ocking effect of BVD/CA 26 indicates that this cellular plasma membrane pro tein is involved in the endocytic pathway of BVDV particles. (C) 2000 Elsev ier Science B.V. All rights reserved.