Localization of host poly(A)+ mRNA in the ribosome profile of mengovirus-infected Ehrlich ascites tumor cells.
The distribution of poly(A)+ mRNA among polysomes, monosomes, and ribosome-free supernatant fractions after mengovirus infection of Ehrlich ascites tumor (EAT) cells was investigated employing sucrose gradient centrifugation of their corresponding postnuclear supernatants. Poly(A)+ mRNA was isolated from sucrose gradient fractions and quantitated in a cell-free protein synthesizing system from uninfected EAT cells. It was also localized by annealing [3H]-poly(U) to the poly(A)-tracts of mRNA present in the sucrose gradient fractions. Both experiments revealed a gradual shift of host poly(A)+ mRNA from large to small polysomes and monosomes, respectively, with the time postinfection. The greatest part of host template RNA appears to remain ribosome-bound and only a fraction seems to be detached from the ribosomes in the course of mengovirus infection. At the end of the infectious cycle, 8 h postinfection, approximately 70% of the poly(A)+ mRNA detected in uninfected cells is still biologically active, but not translated in vivo, in agreement with data from the [3H]poly(U)hybridization experiment.
D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism*; D008574:Mengovirus; D011061:Poly A; D011132:Polyribosomes / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis*; D012334:RNA, Neoplasm / Q000032:analysis; D012335:RNA, Ribosomal / Q000032:analysis; D012270:Ribosomes / Q000032:analysis*
D012333:RNA, Messenger; D012334:RNA, Neoplasm; D012335:RNA, Ribosomal; D011061:Poly A