title: The quaternary structure of the adenovirus 12 early region 1B 54K protein.
abstract: The quaternary structure of the adenovirus early region 1B 54K protein has been examined under denaturing and nondenaturing conditions. In the presence of SDS the protein has a strong tendency to form disulfide-linked high-molecular-weight polymers. Under nondenaturing, but reducing, conditions the in vitro-translated 54K polypeptide forms oligomers (probably tetramers) of molecular weight approximately 2 x 10(5). After subcellular fractionation of Ad12 early region 1-transformed cells, the 54K E1B protein present in the cytoplasm had a molecular weight similar to that determined for the in vitro-translated material. However, two populations of the viral protein could be distinguished in the nucleus-one of a size similar to that seen in the cytoplasm and the other of appreciably higher molecular weight (approximately 2 x 10(6)). No difference in migration pattern was observed after treatment of the nuclear extract with DNase I or RNase. A proportion of the Ad12 E1B 54K protein in both the high- and the low-molecular-weight populations in the nucleus was found to form a complex with p53, and it is therefore concluded that the very high molecular weight derives from interaction with an, as yet, unidentified component.
authors.affiliation: Department of Cancer Studies, University of Birmingham, United Kingdom.
authors.forename: R J
authors.initials: RJ
authors.lastname: Grand
authors.forename: T
authors.initials: T
authors.lastname: Mustoe
authors.forename: S
authors.initials: S
authors.lastname: Roberts
authors.forename: P H
authors.initials: PH
authors.lastname: Gallimore
mesh_terms: D017501:Adenovirus E1B Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D000260:Adenoviruses, Human / Q000737:chemistry*; D002458:Cell Fractionation; D002461:Cell Line, Transformed; D002467:Cell Nucleus / Q000821:virology; D002474:Cell-Free System; D003593:Cytoplasm / Q000821:virology; D006801:Humans; D008970:Molecular Weight; D014176:Protein Biosynthesis; D011487:Protein Conformation; D011489:Protein Denaturation; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D017501:Adenovirus E1B Proteins; D016159:Tumor Suppressor Protein p53