In-gel digestion for mass spectrometric characterization of RNA from fluorescently stained polyacrylamide gels.
Although current mass spectrometry-based proteomics technology allows for high-throughput analysis of protein components in functional ribonucleoprotein complexes, this technology has had limited application to studies of RNA itself. Here we present a protocol for RNA analysis using polyacrylamide gel electrophoresis coupled with liquid chromatography-tandem mass spectrometry. Specifically, RNAs of interest are subjected to polyacrylamide gel electrophoresis and stained with a fluorescent dye, and RNAs in gel bands are digested with nuclease and then analyzed directly liquid chromatography-mass spectrometry, resulting in highly accurate mass values and reliable information on post-transcriptional modifications. We demonstrate that the method can be applied to the identification and chemical analysis of small RNAs in mouse embryonic stem cell extracts and of small RNAs in the spliceosomal ribonucleoprotein complex pulled down from yeast cells using a tagged protein cofactor as bait. The protocol is relatively simple and allowed us to identify not only three novel methylated nucleotide residues of RNase P RNA, U6 snRNA, and 7SL RNA prepared from mouse ES cells but also various 3'-end forms of U4, U5S, and U6 snRNAs isolated from the yeast spliceosome at the femtomole level. The method is thus a convenient tool for direct analysis of RNAs in various cellular ribonucleoprotein complexes, particularly for the analysis of post-transcriptional modifications and metabolic processing of RNA.
Taoka
Masato
M
Department of Chemistry, Graduate School of Sciences and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan. mango@tmu.ac.jp
Ikumi
Maki
M
Nakayama
Hiroshi
H
Masaki
Shunpei
S
Matsuda
Ryozo
R
Nobe
Yuko
Y
Yamauchi
Yoshio
Y
Takeda
Jun
J
Takahashi
Nobuhiro
N
Isobe
Toshiaki
T
D000180:Acrylic Resins / Q000737:chemistry*; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D057225:Data Mining; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D053595:Embryonic Stem Cells; D005456:Fluorescent Dyes / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D051379:Mice; D012313:RNA / Q000032:analysis* / Q000235:genetics / Q000302:isolation & purification; D012331:RNA, Fungal / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification; D012342:RNA, Small Nuclear / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification; D012441:Saccharomyces cerevisiae; D053719:Tandem Mass Spectrometry
D000180:Acrylic Resins; D005456:Fluorescent Dyes; D012331:RNA, Fungal; D012342:RNA, Small Nuclear; C016680:polyacrylamide gels; D012313:RNA