Identification of the RNA chaperone activity of recombinant human tumor necrosis factor alpha in vitro.

RNA chaperones are defined as proteins that aid in the process of RNA folding by processing misfolding or by resolving misfolded structures. Although RNA chaperones are ubiquitous and abundant in all living organisms and viruses, there are no any reports that a cytokine has such RNA chaperone activity. Here, we demonstrate for the first time that recombinant human tumor necrosis factor alpha (rhTNF-α), a well-known cytokine, has RNA chaperone activity in vitro. rhTNF-α binds random 68 nt RNAs strongly at the minimal concentration of 10μM with a broad sequence specificity. Our results also show that rhTNF-α facilitates annealing and strand exchange, and promotes the cleavage of a 17-nucleotide substrate S by hammerhead ribozyme HH16. The role of TNF-α as an RNA chaperone in vivo is not clear, but we propose that TNF-α may play an important role as an RNA chaperone during the process of some infectious and inflammatory diseases.