An adenovirus 2-coded tumor antigen located on the endoplasmic reticulum and nuclear envelope is required for growth of transformed cells in Ca2+-deficient media.
Rat embryo cell lines containing the adenovirus 2 E1a region together with normal or mutant forms of the N-terminal half of the E1b region (HindIII G fragment) were generated by using a dominant selection marker, neo. Biochemically transformed cells containing a nonmutated HindIII G fragment proliferated more rapidly in Ca2+-deficient media, whereas cells containing a specific deletion within the E1b-encoded, 175-amino-acid (175R) (19-kilodalton) T-antigen gene and nontransformed cells grew at a slower rate. Furthermore, transformed cells that did not express the 175R T antigen and untransformed cells could not replicate their DNA efficiently in low-Ca2+ medium. Our results suggest that Ca2+ ions may provide an important stimulus for cell proliferation in adenovirus-transformed cells through a mechanism that involves the functions of the 175R T antigen.
D000260:Adenoviruses, Human / Q000235:genetics*; D000818:Animals; D000951:Antigens, Neoplasm / Q000235:genetics*; D002118:Calcium / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002472:Cell Transformation, Viral; D003470:Culture Media; D004261:DNA Replication / Q000187:drug effects; D004262:DNA Restriction Enzymes; D004622:Embryo, Mammalian; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D007700:Kinetics; D009154:Mutation; D009685:Nuclear Envelope / Q000378:metabolism*; D051381:Rats
D000951:Antigens, Neoplasm; D003470:Culture Media; D004262:DNA Restriction Enzymes; D002118:Calcium