Biomaterial Database

Evidence that the middle T antigen of polyomavirus interacts with the membrane skeleton. 1993

D W Andrews, and J Gupta, and G Abisdris

Department of Biochemistry, McMaster University, Hamilton, Ontario, Canada.

The transforming protein of polyomavirus, middle T antigen, is associated with cellular membranes. We have examined the subcellular location of the middle T antigen in two different cell types by fractionation and detergent phase partitioning. Middle T antigen expressed in human cells by a recombinant adenovirus was detected primarily in the membrane skeleton. Sucrose gradient fractionation revealed that the middle T antigen was associated with complexes with molecular weights of 500,000 to 1,000,000. Several markers for cytoskeleton cofractionate with these complexes, including actin, tubulin, and vimentin. Electron micrographs of membrane skeleton prepared from cells expressing middle T antigen demonstrated that this material contained primarily fibrous structures and was clearly devoid of bilayer membranes. These structures were distinct from the filamentous structures observed in fractions enriched for cytoskeleton. Consistent with a role for membrane skeleton localization in transformation, middle T antigen was detected exclusively in fractions enriched for membrane skeleton in middle T antigen-transformed Rat-2 cells. Our results may resolve the apparent difference between middle T antigen localization as determined by immunomicroscopy and that determined by subcellular fractionation.

UI	MeSH Term	Description	Entries
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D011120	Polyomavirus	A genus of potentially oncogenic viruses of the family POLYOMAVIRIDAE. These viruses are normally present in their natural hosts as latent infections. The virus is oncogenic in hosts different from the species of origin.	Bovine polyomavirus,Murine polyomavirus,Hamster polyomavirus,Polyoma Virus,Polyoma Viruses,Bovine polyomaviruses,Hamster polyomaviruses,Murine polyomaviruses,Polyomaviruses,Virus, Polyoma,Viruses, Polyoma,polyomavirus, Hamster,polyomaviruses, Bovine,polyomaviruses, Murine
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D002451	Cell Compartmentation	A partitioning within cells due to the selectively permeable membranes which enclose each of the separate parts, e.g., mitochondria, lysosomes, etc.	Cell Compartmentations,Compartmentation, Cell,Compartmentations, Cell
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D003598	Cytoskeletal Proteins	Major constituent of the cytoskeleton found in the cytoplasm of eukaryotic cells. They form a flexible framework for the cell, provide attachment points for organelles and formed bodies, and make communication between parts of the cell possible.	Proteins, Cytoskeletal
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000952	Antigens, Polyomavirus Transforming	Polyomavirus antigens which cause infection and cellular transformation. The large T antigen is necessary for the initiation of viral DNA synthesis, repression of transcription of the early region and is responsible in conjunction with the middle T antigen for the transformation of primary cells. Small T antigen is necessary for the completion of the productive infection cycle.	Polyomavirus Large T Antigens,Polyomavirus Middle T Antigens,Polyomavirus Small T Antigens,Polyomavirus T Proteins,Polyomavirus Transforming Antigens,Polyomavirus Tumor Antigens,SV40 T Antigens,SV40 T Proteins,Simian Sarcoma Virus Proteins,Polyomaviruses Large T Proteins,Polyomaviruses Middle T Proteins,Polyomaviruses Small T Proteins,Antigens, Polyomavirus Tumor,Antigens, SV40 T,Proteins, Polyomavirus T,Proteins, SV40 T,T Antigens, SV40,T Proteins, Polyomavirus,T Proteins, SV40,Transforming Antigens, Polyomavirus,Tumor Antigens, Polyomavirus
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In