An siRNA ribonucleoprotein is found associated with polyribosomes in Trypanosoma brucei.
Genetic interference by double-stranded RNA (dsRNA) or RNA interference (RNAi) triggers the sequence-specific degradation of cellular transcripts. The mediators of mRNA degradation are small interfering RNAs (siRNAs). Here, we report that in Trypanosoma brucei, 10%-20% of siRNAs cosediment with polyribosomes. Preventing the assembly of ribosomes on mRNAs results in a concomitant decrease of siRNAs sedimenting as high-molecular-weight complexes. We further provide evidence that siRNAs are associated with translating ribosomes and that this association is mediated by a 70-kD ribonucleoprotein complex.
Djikeng
Appolinaire
A
Department of Internal Medicine, Yale University Medical School, New Haven, Connecticut 06520-8022, USA.
Shi
Huafang
H
Tschudi
Christian
C
Shen
Shuiyuan
S
Ullu
Elisabetta
E
D000818:Animals; D008970:Molecular Weight; D011132:Polyribosomes / Q000235:genetics*; D012330:RNA, Double-Stranded / Q000235:genetics; D016053:RNA, Protozoan / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics* / Q000302:isolation & purification; D012261:Ribonucleoproteins / Q000235:genetics; D014346:Trypanosoma brucei brucei / Q000235:genetics*
D012330:RNA, Double-Stranded; D016053:RNA, Protozoan; D034741:RNA, Small Interfering; D012261:Ribonucleoproteins