A 6700 MW membrane protein is encoded by region E3 of adenovirus type 2.
There is an open reading frame between ATG1022 and TGA1205 in the E3 transcription unit of adenovirus 2 that could encode a protein of MW 6700 (6.7K) (61 amino acids). To address whether this protein is expressed, we prepared an antiserum against a synthetic peptide corresponding to residues 47-61 in the 6.7K protein. This antiserum immunoprecipitated two series of protein bands, a 7K-8K doublet and a 15K-16K doublet or triplet, as observed by electrophoresis on 10-18% gradient SDS-polyacrylamide gels. These bands were not obtained from cells infected with mutants that lack the 6.7K gene. Most, if not all, of the 7K-8K and 15K-16K bands were detected by immunoblot, indicating that they are modified versions of the 6.7K protein. Only an 8K band was observed after cell-free translation of hybridization-purified mRNA, suggesting that this may be the primary translation product. As judged by DNA sequence, the 6.7K protein has a hydrophobic domain of at least 22 residues (residues 16-37), suggesting that 6.7K may be a membrane protein. Consistent with this, the 7K-8K and 15K-16K bands were observed in the crude membrane but not the cytosol or nuclear fractions of biochemically fractionated cells. The 6.7K protein was underproduced by mutants which underproduce E3 mRNAs a and c, indicating that 6.7K is translated from these mRNAs. Since the E3-gp 19K protein is also translated from mRNAs a and c, these mRNAs are bicistronic. The 6.7K protein is well-conserved in Ad5 (Ad2 and Ad5 are group C adenoviruses), and appears to be marginally conserved in Ad3 (group B).
Institute for Molecular Virology, St. Louis University Medical Center, Missouri 63110.
J
J
Wilson-Rawls
S K
SK
Saha
P
P
Krajcsi
A E
AE
Tollefson
L R
LR
Gooding
W S
WS
Wold
D017456:Adenovirus Early Proteins; D000258:Adenovirus Infections, Human / Q000235:genetics; D000260:Adenoviruses, Human / Q000235:genetics*; D000595:Amino Acid Sequence; D015153:Blotting, Western; D002474:Cell-Free System / Q000378:metabolism; D002478:Cells, Cultured; D003001:Cloning, Molecular; D000939:Epitopes / Q000235:genetics; D006801:Humans; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation; D009856:Oncogene Proteins, Viral / Q000096:biosynthesis / Q000235:genetics*; D011233:Precipitin Tests; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*
D017456:Adenovirus Early Proteins; D000939:Epitopes; D008565:Membrane Proteins; D009856:Oncogene Proteins, Viral; D012333:RNA, Messenger; D014157:Transcription Factors