title: Studies on polysomes synthesizing influenza virus haemagglutinin.
abstract: A fraction of polysomes synthesizing fowl plague virus (FPV) haemagglutinin (HA) was isolated from an infected chick embryo fibroblast (CEF) culture using a double immunoprecipitation assay. In an immunoprecipitate of HA-synthesizing polysomes (HA precipitate) the content of the HA polypeptide was increased with respect to the M1 + NS1 polypeptides as compared to a preparation of unprecipitated polysomes. In the HA precipitate, besides mRNA coding for HA synthesis, we have detected mRNAs corresponding to genes 1, 2 and 3 coding for high molecular weight P proteins. Studies of a cytoplasmic extract (CE) from FPV-infected CEF cultures in a sucrose density gradient revealed a fraction of polysomes with a sedimentation value of about 500S; the composition of virus-specific polypeptides and mRNA of the fraction was similar to that of the HA precipitate. It is thought that P proteins are synthesized on membrane-bound polysomes located closely to HA-synthesizing polysomes.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D006388:Hemagglutinins / Q000302:isolation & purification*; D009980:Influenza A virus / Q000276:immunology / Q000378:metabolism*; D011132:Polyribosomes / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D014764:Viral Proteins / Q000096:biosynthesis*
chemical_list: D006388:Hemagglutinins; D012333:RNA, Messenger; D014764:Viral Proteins