Association of pp60src and src protein kinase activity with the plasma membrane of nonpermissive and permissive avian sarcoma virus-infected cells.

Theintracellular localization ofpp6O0andsrcprotein kinase activity inavian sarcoma virus (ASV)-infected chicken embryofibroblasts andtransformed and morphologically reverted field vole cells wanexamined bysubcellular fractionation procedures. Fractionation bydifferential centrifugation ofDounce-homogenized cellular extracts prepared fromvolecells showedthat83to91%ofpp60O sedimented withparticulate subcellular components frombothtransformed and revertant volecells. A slightly lesser amount(60to70%)ofpp60"wasfound associated withtheparticulate fraction fromASV-infected chicken embryo fibroblasts. Thedistribution ofsrcprotein kinase activity inthecytosol andparticulate cell fractions wasidentical tothat ofpp60", indicating nodetectable differences intheactivity ofcytosol- andparticulate-associated pp60.Whensubcellular components ofthecell werefractionated bydiscontinuous sucrose gradient centrifugation, similar amounts ofbothpp60andsrcprotein kinase activity cosedimented withtheplasma membrane fractions frombothtransformed and revertant vole cells, aswell asfromASV-infected chicken embryo fibroblasts. src protein kinase activity associated withplasma membrane fractions prepared from vole cells andASV-infected chicken embryo fibroblasts wasresistant toextraction withhighsalt concentrations, butpartial elution wasachieved withnonionic detergent. Thus, inbothtransformed andmorphologically reverted volecells, pp60isintimately associated withtheplasma membrane. Since transforming virus canberescued fromrevertant volecells byfusion tochicken embryo fibroblsts, revertant vole cell pp60iscapable ofinducing morphological transformation. Thus, although thedatapresented herein suggest thattransformation requires theassociation ofpp60withtheplasma membrane, thebinding of pp608' totheplasma membrane perseisinsufficient toinduce morphological transformation andrequires theadditional interaction withaspecific target membrane protein whichappears tobedefective inrevertant volecells. Transformation ofcells byavian sarcoma viruses (ASV)ismediated bya60,000-dalton virus-coded polypeptide, pp60,whichfunctions asa phosphotransferase