Copb1-facilitated axonal transport and translation of κ opioid-receptor mRNA
- Department of Pharmacology, University of Minnesota Medical School, 6-120 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455
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Edited by Solomon H. Snyder, Johns Hopkins University School of Medicine, Baltimore, MD, and approved June 29, 2007 (received for review April 25, 2007)
Abstract
mRNA of κ opioid receptor (KOR) can be transported to nerve fibers, including axons of dorsal root ganglia (DRG), and can be locally translated. Yeast three-hybrid screening identifies Copb1 as a kor mRNA-associated protein that form complexes with endogenous kor mRNA, which are colocalized in the soma and axons of DRG neurons. Axonal transport of kor mRNA is demonstrated, directly, by observing mobilization of biotin-labeled kor mRNA in Campenot chambers. Efficient transport of kor mRNA into the side chamber requires Copb1 and can be blocked by a drug that disrupts microtubules. The requirement for Copb1 in mobilizing kor mRNA is confirmed by using the MS2–GFP mRNA-tagging system. Furthermore, Copb1 also facilitates the translation of kor mRNA in the soma and axons. This study provides evidence for a microtubule-dependent, active axonal kor mRNA-transport process that involves Copb1 and can stimulate localized translation and suggests coupling of transport and translation of mRNAs destined to the remote areas such as axons.
Footnotes
- *To whom correspondence should be addressed. E-mail: weixx009{at}umn.edu
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Author contributions: J.B., N.-P.T., and L.-N.W. designed research; J.B., N.-P.T., and H.-Y.L. performed research; H.H.L. and L.-N.W. contributed new reagents/analytic tools; J.B., N.-P.T., and L.-N.W. analyzed data; and J.B. and L.-N.W wrote the paper.
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The authors declare no conflict of interest.
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This article is a PNAS Direct Submission.
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This article contains supporting information online at www.pnas.org/cgi/content/full/0703805104/DC1.
- Abbreviations:
- DRG,
- dorsal root ganglia;
- HuR,
- Hu antigen R;
- KOR,
- κ opioid receptor.
- © 2007 by The National Academy of Sciences of the USA
