title: Phosphorylation of p68 RNA helicase regulates RNA binding by the C-terminal domain of the protein.
abstract: We previously reported ATPase, RNA unwinding, and RNA-binding activities of recombinant p68 RNA helicase that was expressed in Escherichia coli. Huang et al. The recombinant protein bound both single-stranded (ss) and double-stranded (ds) RNAs. To further characterize the substrate RNA binding by p68 RNA helicase, we expressed and purified the recombinant N-terminal and C-terminal domains of the protein. RNA-binding property and protein phosphorylation of the recombinant domains of p68 were analyzed. Our data demonstrated that the C-terminal domain of p68 RNA helicase bound ssRNA. More interestingly, the C-terminal domain was a target of protein kinase C (PKC). Phosphorylation of the C-terminal domain of p68 abolished its RNA binding. Based on our observations, we propose that the C-terminal domain is an RNA substrate binding site for p68. The protein phosphorylation by PKC regulates the RNA binding of p68 RNA helicase, which consequently controls the enzymatic activities of the protein.
authors.affiliation: Department of Biology, Georgia State University, Atlanta, GA 30303, USA.
authors.forename: Liuqing
authors.initials: L
authors.lastname: Yang
authors.forename: Jenny
authors.initials: J
authors.lastname: Yang
authors.forename: Youliang
authors.initials: Y
authors.lastname: Huang
authors.forename: Zhi Ren
authors.initials: ZR
authors.lastname: Liu
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry; D001665:Binding Sites; D053487:DEAD-box RNA Helicases; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D008957:Models, Genetic; D010766:Phosphorylation; D011485:Protein Binding; D011493:Protein Kinase C / Q000378:metabolism; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D020365:RNA Helicases / Q000737:chemistry / Q000378:metabolism*; D012330:RNA, Double-Stranded / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D014158:Transcription, Genetic; D014466:Ultraviolet Rays
chemical_list: D012330:RNA, Double-Stranded; D011994:Recombinant Proteins; D012313:RNA; D004247:DNA; D011494:Protein Kinases; D011493:Protein Kinase C; D000251:Adenosine Triphosphatases; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases