| Abstract: | Studies of virus-specific proteins of type D retroviruses by radioimmunoprecipitation (RIP) using various radioactive precursors demonstrated in HEp-2 cells producing these retroviruses the presence of two glycosylated gag-coded polyproteins with molecular weights of 78 K and 90 K. The same polyproteins were found by lactoperoxidase iodination and RIP on the plasma membrane of the cells. Comparative studies of these glycoproteins by the limited proteolysis method showed the sites for trypsin action in them to be located in similar places of protein bases which indicated their structural relationship. It is suggested that glycosylated gag-coded polyproteins of retroviruses (including type D retroviruses) play the role of receptors for certain mitogens the seizure of which stimulates cell proliferation. |
