title: Adenoviral heterogeneous nuclear RNA is associated with host cell proteins.
abstract: In this study irradiation of intact cells with 244-nm ultraviolet light was used to cross-link hnRNA to proteins that are closely associated with it. In this way proteins interacting specifically with hnRNA could be identified excluding the possibility of non-specific binding of proteins to the RNA during cell fractionation. In uninfected HeLa cells two polypeptides of 41500 and 43000 molecular weight can be cross-linked very efficiently to hnRNA. Other proteins, with molecular weights of 36000 and 37000, were covalently linked less effectively. Irradiation of adenovirus-infected cells results in the cross-linking of the same polypeptides to hnRNA. It was found, however, that hnRNA from adenovirus-infected cells contains both viral and host transcripts. Both classes of transcripts are quantitatively associated with the nuclear matrix and can be cross-linked by irradiation with equal efficiency. To determine whether both adenoviral and cellular transcripts are associated with the same proteins, the cross-linked adenoviral hnRNA-protein complexes were isolated by preparative hybridization to adenoviral DNA immobilized on Sepharose. The results show that the purified cross-linked adenoviral hnRNA-protein complexes also contain the host 41500-Mr and 43000-Mr proteins as major components. This suggests that in the infected cell adenoviral-specific hnRNA is associated with host proteins and that the structural organization of viral hnRNA-protein complexes in infected cells probably is similar to the organization of host hnRNA in uninfected cells.
mesh_terms: D000256:Adenoviridae / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism* / Q000382:microbiology; D003432:Cross-Linking Reagents; D004279:DNA, Viral / Q000302:isolation & purification; D006367:HeLa Cells; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D009693:Nucleic Acid Hybridization; D009698:Nucleoproteins / Q000302:isolation & purification*; D012332:RNA, Heterogeneous Nuclear / Q000302:isolation & purification*; D012367:RNA, Viral / Q000302:isolation & purification*; D012261:Ribonucleoproteins / Q000302:isolation & purification*
chemical_list: D003432:Cross-Linking Reagents; D004279:DNA, Viral; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D009698:Nucleoproteins; D012332:RNA, Heterogeneous Nuclear; D012367:RNA, Viral; D012261:Ribonucleoproteins