FIGURE 1.

Identification of GRP78 as TMUV-binding membrane protein. (A) Detection of protein involved in TMUV binding in BHK-21 cell membrane by VOPBA. The PVDF membrane containing BHK-21 cell membrane proteins were incubated without (Lane 1) or with 10⁵ TCID₅₀ of TMUV (Lane 2). Virus binding bands were detected by monoclonal antibody against TMUV. The approximate 70 kDa band was observed in Lane 2 (black arrow). Lane 3, molecular weight marker. (B) Coomassie staining of the membrane protein extracted from BHK-21 cells. Lane 1, molecular weight marker; Lane 2, membrane protein extracted from BHK-21 cells. (C) Co-immunoprecipitation assay of TMUV binding membrane protein. The membrane protein extracted from BHK-21 cells immunoprecipitated with (Lane 1) or without (Lane 2) TMUV. The immunoprecipitated complexes were analyzed by SDS-PAGE and transferred to PVDF membrane. The membrane was then incubated with anti-GRP78 antibody. The approximate 70 kDa band was observed in Lane 1 (black arrow). Lane 3, molecular weight marker. (D) Identification of TMUV binding protein by mass spectrometry. The peptide sequences of GRP78 identified by mass spectrometry were underlined.