Requirements for mouse mammary tumour virus internalization in mouse mammary epithelial cells.
Methylamine, a lysosomotropic alkalinizing agent, blocked mouse mammary tumour virus (MMTV) infection in normal mouse mammary epithelium, suggesting that internalization and acidification are necessary for cell penetration. This mechanism was further supported by the fact that intact MMTV induced the translocation of its cellular binding protein from the plasmalemma to the microsomes; however, isolated gp52, the MMTV envelope protein that binds this receptor, did not redistribute the binding protein. These data suggest that either another viral component, in addition to gp52, is needed for cell entry or that internalization requires receptor aggregation, which only the multivalent viral envelope can induce.
Bolander
F F
FF
Department of Biological Sciences, University of South Carolina, Columbia 29208, USA. Bolander@Biol.SC. Edu
D000818:Animals; D000957:Antigens, Viral, Tumor / Q000378:metabolism*; D046508:Culture Techniques; D004847:Epithelial Cells; D004848:Epithelium / Q000821:virology; D005260:Female; D008321:Mammary Glands, Animal / Q000166:cytology / Q000821:virology*; D008324:Mammary Tumor Virus, Mouse / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H; D010766:Phosphorylation; D011991:Receptors, Virus / Q000378:metabolism; D012756:Sheep; D013552:Swine
D000957:Antigens, Viral, Tumor; D011991:Receptors, Virus; C040612:glycoprotein 52 antigen, Mouse mammary tumor virus