Murine leukemia virus (T-8)-transformed cells: identification of a precursor polyprotein containing gag gene-coded proteins (p15 and p12) and a nonstructural component.

Mink cells nonproductively transformed by the T-8 strain of mink cell focus-inducing virus express two type C viral amino terminal gag gene-coded structural proteins, p15 and p12, in the form of a 90,000 to 110,000 molecular weight polyprotein that lacks detectable immunological reactivity with other known type C virus-coded translational products. The observation concurs with the previous demonstration of similar high-molecular-weight precursor polyproteins in cell lines nonproductively transformed by either of two other mammalian sarcoma viruses also limited in virus-coded structural protein expression to p15 and p12.