VIEW ARTICLE

Molecular Plant Pathology

Baculovirus Expression and Processing of Tomato Spotted Wilt Tospovirus Glycoproteins. Scott Adkins, Department of Plant Pathology, University of Wisconsin-Madison; Tae-Jin Choi(2), Barbara A. Israel(3), Murali D. Bandla(4), Kathryn E. Richmond(5), Kevin T. Schultz(6), John L. Sherwood(7), and Thomas L. German(8). (2)Department of Plant Pathology, University of Wisconsin-Madison, Current address: National Fisheries University of Pusan, Department of Microbiology, 599-1, Daeyeon 3-Dong, Nam-Gu, Pusan 608-737, Korea; (5)(8)Department of Plant Pathology, University of Wisconsin-Madison; (3)Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison 53706; (6)Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison 53706, Current address: Merck Research Laboratories, P.O. Box 2000 RY33-216, Rahway, NJ 07065; (4)(7)Department of Plant Pathology, Oklahoma State University, Stillwater 74078. Phytopathology 86:849-855. Accepted for publication 22 April 1996. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/Phyto-86-849.

The open reading frame encoding the polyprotein precursor to the tomato spotted wilt tospovirus (TSWV) G1 and G2 glycoproteins was cloned as cDNA and used to produce a recombinant baculovirus. Protein expression was monitored in recombinant baculovirus-infected Spodoptera frugiperda IPLB-SF21 (SF21) cells with monoclonal antibodies raised to TSWV G1 and G2. Western blot analysis demonstrated expression, proteolytic processing, and glycosylation of the G1G2 polyprotein to yield proteins with serological specificities and electrophoretic mobilities similar to the G1 and G2 proteins found in TSWV virions. Indirect immuno-fluorescence localization of G1 and G2 in infected SF21 cells revealed accumulation of the glycoproteins in the plasmalemma. These experiments establish that the glycoproteins of TSWV, a plant-infecting virus in the family Bunyaviridae, can be processed in the absence of other viral proteins.