P85gag-mos encoded by ts110 Moloney murine sarcoma virus: rapid at the restrictive temperature

The stability of P85gag-mos, encoded by ts110 Moloney murine sarcoma virus, was studied. P85gag-mos was found to turn over more rapidly at 39 degrees C than 33 degrees C in two different cell lines. One of these is a non-producer cell clone (6m2) which appears only to express P85 at 33 degrees C. The other cell line (206-2IC) produces P85gag-mos at both 33 degrees C and 39 degrees C, although in lower amounts at the higher temperature. Both cell lines exhibit the normal morphological phenotype following a shift to the restrictive temperature. These data suggest that the presence of P85gag-mos alone is insufficient to cause transformation, and that some function(s) associated with the molecule may be heat-labile.