Publication Date:
2012-05-13
Description:
We report that the cationic porphyrin TmPyP4, which is known mainly as a DNA G-quadruplex stabilizer, unfolds an unusually stable all purine RNA G-quadruplex (M3Q) that is located in the 5'-UTR of MT3-MMP mRNA. When the interaction between TmPyP4 and M3Q was monitored by UV spectroscopy a 22-nm bathochromic shift and 75% hypochromicity of the porphin major Soret band was observed indicating direct binding of the two molecules. TmPyP4 disrupts folded M3Q in a concentration-dependent fashion as was observed by circular dichroism (CD), 1D 1 H NMR and native gel electrophoresis. Additionally, when TmPyP4 is present during the folding process it inhibits the M3Q RNA from adopting a G-quadruplex structure. Using a dual reporter gene construct that contained the M3Q sequence alone or the entire 5'-UTR of MT3-MMP mRNA, we report here that TmPyP4 can relieve the inhibitory effect of the M3Q G-quadruplex. However, the same concentrations of TmPyP4 failed to affect translation of a mutated construct. Thus, TmPyP4 has the ability to unfold an RNA G-quadruplex of extreme stability and modulate activity of a reporter gene presumably via the disruption of the G-quadruplex.
Print ISSN:
0305-1048
Electronic ISSN:
1362-4962
Topics:
Biology
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