A growth-essential Tetrahymena Piwi protein carries tRNA fragment cargo
- 1Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA;
- 2Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, New York 10029, USA
Abstract
Argonaute/Piwi proteins associate with small RNAs that typically provide sequence specificity for RNP function in gene and genome regulation. Here we show that Twi12, a Tetrahymena Piwi protein essential for growth, is loaded with mature tRNA fragments. The tightly bound ∼18- to 22-nucleotide tRNA 3′ fragments are biochemically distinct from the tRNA halves produced transiently in response to stress. Notably, the end positions of Twi12-bound tRNA 3′ fragments precisely match RNAs detected in total small RNA of mouse embryonic stem cells and human cancer cells. Our studies demonstrate unanticipated evolutionary conservation of mature tRNA processing to tRNA fragment small RNAs.
Keywords
Footnotes
-
↵3 Corresponding author.
E-MAIL kcollins{at}berkeley.edu; FAX (510) 643-6791.
-
Article published online ahead of print. Article and publication date are online at http://www.genesdev.org/cgi/doi/10.1101/gad.1996210.
-
Supplemental material is available for this article.
- Received September 24, 2010.
- Accepted October 22, 2010.
- Copyright © 2010 by Cold Spring Harbor Laboratory Press
