Synthesis of Site-Specifically Phosphate-Caged siRNAs.
Photolabile small interfering RNA (siRNA) oligonucleotide duplexes are becoming a powerful tool for photoregulation of gene expression through an RNA interference (RNAi) mechanism. Terminal or statistical labeling of siRNAs has been previously achieved. Recently, we have shown a new strategy for site-specific incorporation of a photolabile group (1-(2-nitrophenyl)ethyl [NPE]) at any phosphate position of siRNA strands for photomodulation of their gene-silencing activity. In this unit, we first describe in detail the syntheses of four new NPE protected nucleoside phosphoramidites (dA 0, dG 0, dC 0, dT 0) and 2-cyanoethyl-1-(2-nitrophenyl)ethyl-N,N'-diisopropylphosphoramidite (N 0). They are then site specifically incorporated into any position of RNA oligonucleotides according to standard phosphoramidite chemistry. Phosphate-caged siRNA duplexes are then prepared by hybridization of single-stranded RNAs containing the 1-(2-nitrophenyl)ethyl caging moiety on the phosphate group with their complementary RNA.
State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China.|School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China.
Li
L
Wu
State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China.
Jie
J
Wang
State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China.
Xinjing
X
Tang
D006801:Humans; D010710:Phosphates / Q000737:chemistry; D034622:RNA Interference / Q000502:physiology; D034741:RNA, Small Interfering / Q000737:chemistry* / Q000235:genetics*
D010710:Phosphates; D034741:RNA, Small Interfering
RNAi; phosphate-caged siRNA; photoregulation; site-specific; uncaging