QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Vol. 19, Issue 10, 4154-4166, October 2008

This Article Full Text Full Text (PDF) Supplemental Materials All Versions of this Article: E08-05-0513v1 19/10/4154    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Aizer, A. Articles by Shav-Tal, Y. Search for Related Content PubMed PubMed Citation Articles by Aizer, A. Articles by Shav-Tal, Y.

The Dynamics of Mammalian P Body Transport, Assembly, and Disassembly In Vivo

Adva Aizer^*, Yehuda Brody^*, Lian Wee Ler, Nahum Sonenberg, Robert H. Singer, and Yaron Shav-Tal^*

*The Mina and Everard Goodman Faculty of Life Sciences and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel; Department of Biochemistry and McGill Cancer Center, McGill University, Montreal, Quebec H3G 1Y6, Canada; and Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461

Submitted May 22, 2008; Revised July 14, 2008; Accepted July 15, 2008
Monitoring Editor: Marvin Wickens

Exported mRNAs are targeted for translation or can undergo degradation by several decay mechanisms. The 5'3' degradation machinery localizes to cytoplasmic P bodies (PBs). We followed the dynamic properties of PBs in vivo and investigated the mechanism by which PBs scan the cytoplasm. Using proteins of the decapping machinery, we asked whether PBs actively scan the cytoplasm or whether a diffusion-based mechanism is sufficient. Live-cell imaging showed that PBs were anchored mainly to microtubules. Quantitative single-particle tracking demonstrated that most PBs exhibited spatially confined motion dependent on microtubule motion, whereas stationary PB pairs were identified at the centrosome. Some PBs translocated in long-range movements on microtubules. PB mobility was compared with mitochondria, endoplasmic reticulum, peroxisomes, SMN bodies, and stress granules, and diffusion coefficients were calculated. Disruption of the microtubule network caused a significant reduction in PB mobility together with an induction of PB assembly. However, FRAP measurements showed that the dynamic flux of assembled PB components was not affected by such treatments. FRAP analysis showed that the decapping enzyme Dcp2 is a nondynamic PB core protein, whereas Dcp1 proteins continuously exchanged with the cytoplasm. This study reveals the mechanism of PB transport, and it demonstrates how PB assembly and disassembly integrate with the presence of an intact cytoskeleton.

Author contributions: A. A. and Y.S.-T. designed and performed the experiments. Y. B. programmed the tracking module and performed the FRAPs. L.L.W., N. S., and R.H.S. contributed reagents/materials/ analysis tools. Y.S.-T. wrote the paper.

Address correspondence to: Yaron Shav-Tal (shavtaly{at}mail.biu.ac.il)

Abbreviations used: ActD, actinomycin D; FISH, fluorescence in situ hybridization; MSD, mean square displacement; PB, P body; SG, stress granule.

This article has been cited by other articles:

				K. G. Chernov, A. Barbet, L. Hamon, L. P. Ovchinnikov, P. A. Curmi, and D. Pastre Role of Microtubules in Stress Granule Assembly: MICROTUBULE DYNAMICAL INSTABILITY FAVORS THE FORMATION OF MICROMETRIC STRESS GRANULES IN CELLS J. Biol. Chem., December 25, 2009; 284(52): 36569 - 36580. [Abstract] [Full Text] [PDF]

				M. Loschi, C. C. Leishman, N. Berardone, and G. L. Boccaccio Dynein and kinesin regulate stress-granule and P-body dynamics J. Cell Sci., November 1, 2009; 122(21): 3973 - 3982. [Abstract] [Full Text] [PDF]

				W.-L. Chang and W.-Y. Tarn A role for transportin in deposition of TTP to cytoplasmic RNA granules and mRNA decay Nucleic Acids Res., October 1, 2009; 37(19): 6600 - 6612. [Abstract] [Full Text] [PDF]