Activities of Adenovirus Virus-Associated RNAs: Purification and Characterization of RNA Binding Proteins

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 95; no. 15; pp. 8514 - 8519
• Main Authors: Liao, Huey-Jane, Kobayashi, Ryuji, Mathews, Michael B.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 21.07.1998; National Acad Sciences; The National Academy of Sciences
• Subjects: Adenoviridae - genetics; Adenoviruses; Amino Acid Sequence; Antibodies; Biological Sciences; Blotting, Northern; Blotting, Western; Cell Line; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - isolation & purification; DNA-Binding Proteins - metabolism; Double stranded RNA; Gels; Human adenovirus; Humans; Kidney cells; Molecular Sequence Data; NFATC Transcription Factors; Nuclear Factor 45 Protein; Nuclear Factor 90 Proteins; Nuclear Proteins; Proteins; RNA; RNA binding proteins; RNA Helicases; RNA Nucleotidyltransferases - chemistry; RNA Nucleotidyltransferases - isolation & purification; RNA Nucleotidyltransferases - metabolism; RNA, Viral - genetics; RNA, Viral - metabolism; RNA-Binding Proteins - chemistry; RNA-Binding Proteins - isolation & purification; RNA-Binding Proteins - metabolism; T lymphocytes; Transcription Factors - chemistry; Transcription Factors - isolation & purification; Transcription Factors - metabolism; Viruses
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.95.15.8514

Most human adenoviruses encode two virus-associated (VA) RNAs, VA RNAIand VA RNAII, that accumulate to high levels in the cytoplasm of infected cells. The function of VA RNAIin blocking the activation of the cellular kinase PKR is well known, but the role of VA RNAIIis obscure. Herein we characterize and purify several human proteins that interact preferentially with VA RNAIIin Northwestern blot assays. Two of these proteins were identified as RNA helicase A and NF90, a component of the heterodimeric nuclear factor of activated T cells (NFAT). They copurified with the smaller NFAT subunit, NF45, which did not bind VA RNAII, and with an unidentified protein, p97, which did bind VA RNAII. Both RNA helicase A and NF90 contain two copies of a double-stranded (ds) RNA binding motif and bind strongly to dsRNA. NF90 interacts with RNAs in the following order of affinity: dsRNA > VA RNAII> VA RNAI> single-stranded RNA. Furthermore, VA RNAIIis more effective than VA RNAIas an inhibitor of RNA helicase activity. These data identify RNA helicase A and NF90 as cellular proteins with an affinity for dsRNA and other structured RNA molecules and suggest that their functions are subject to regulation by RNA ligands including VA RNAII.