Abstract
Argonaute proteins associate with microRNAs (miRNAs) that bind mRNAs through partial base-pairings to primarily repress translation in animals. A fraction of Argonaute proteins and miRNAs biochemically cosediment with polyribosomes, yet another fraction paradoxically accumulates in ribosome-free processing bodies (PBs) in the cytoplasm. In this report, we give a quantitative account of the Argonaute protein localization and dynamics in living cells in different cellular states. We find that the majority of Argonaute is distributed diffusely in the cytoplasm, and, when cells are subjected to stress. Argonaute proteins accumulate to newly assembled structures known as stress granules (SGs) in addition to PBs. Argonaute proteins displayed distinct kinetics at different structures: exchange faster at SGs and much slower at PBs. Further, miRNAs are required for the Argonaute protein localization to SGs but not PBs. These quantitative kinetic data provide insights into miRNA-mediated repression.
Original language | English (US) |
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Pages (from-to) | 18125-18130 |
Number of pages | 6 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 103 |
Issue number | 48 |
DOIs | |
State | Published - Nov 28 2006 |
Externally published | Yes |
Keywords
- Dynamics
- Fluorescence microscopy
- Post-transcriptional control
- Processing bodies
ASJC Scopus subject areas
- General