Characterization of the piRNA complex from rat testes.
Small noncoding RNAs regulate processes essential for cell growth and development, including mRNA degradation, translational repression, and transcriptional gene silencing (TGS). During a search for candidate mammalian factors for TGS, we purified a complex that contains small RNAs and Riwi, the rat homolog to human Piwi. The RNAs, frequently 29 to 30 nucleotides in length, are called Piwi-interacting RNAs (piRNAs), 94% of which map to 100 defined (< or = 101 kb) genomic regions. Within these regions, the piRNAs generally distribute across only one genomic strand or distribute on two strands but in a divergent, nonoverlapping manner. Preparations of piRNA complex (piRC) contain rRecQ1, which is homologous to qde-3 from Neurospora, a gene implicated in silencing pathways. Piwi has been genetically linked to TGS in flies, and slicer activity cofractionates with the purified complex. These results are consistent with a gene-silencing role for piRC in mammals.
Lau
Nelson C
NC
Department of Molecular Biology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA.
Seto
Anita G
AG
Kim
Jinkuk
J
Kuramochi-Miyagawa
Satomi
S
Nakano
Toru
T
Bartel
David P
DP
Kingston
Robert E
RE
D000251:Adenosine Triphosphatases / Q000302:isolation & purification / Q000378:metabolism; D000818:Animals; D033481:Chromosomes, Mammalian; D017124:Conserved Sequence; D004265:DNA Helicases / Q000302:isolation & purification / Q000378:metabolism; D015723:Gene Library; D016678:Genome; D008297:Male; D051379:Mice; D011506:Proteins / Q000302:isolation & purification / Q000378:metabolism*; D034622:RNA Interference; D022661:RNA, Untranslated / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D053484:RecQ Helicases; D012261:Ribonucleoproteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D013737:Testis / Q000737:chemistry*; D014158:Transcription, Genetic
D011506:Proteins; D022661:RNA, Untranslated; D012261:Ribonucleoproteins; C512106:Riwi protein, rat; D000251:Adenosine Triphosphatases; C506725:RECQL protein, human; D004265:DNA Helicases; D053484:RecQ Helicases