CHARACTERIZATION OF AN 11K PROTEIN PRODUCED BY EARLY REGION-3 OF MOUSE ADENOVIRUS TYPE-1

Early region 3 (E3) of mouse adenovirus type 1 produces three mRNAs th at can encode three proteins with unique carboxy-terminal exons. A bac terial fusion protein encoding the unique terminus of one of the three predicted proteins was used to generate antiserum in rabbits. This an tiserum detected a 14K protein on a Western blot of infected cell lysa tes. Immunoprecipitation and endoglycosidase H digestion revealed that the 14K protein was a glycoprotein with a core molecular weight of 11 K, and we are designating this protein E3 gp11K. Through in vitro tran slation experiments we determined that the previously predicted signal sequence of gp11K was cleaved when the protein was expressed during a n infection. Biochemical and immunofluorescence microscopy data indica ted that E3 gp11K was localized to the endoplasmic reticulum of infect ed cells. Biochemical experiments further indicated that gp11K is a pe ripheral membrane protein. (C) 1995 Academic Press, Inc.