Dynein and kinesin regulate stress granule and P-body dynamics.

MARIELA LOSCHI; CLAUDIA C. LEISHMAN; NEDA BERARDONE; GRACIELA L. BOCCACCIO

JOURNAL OF CELL SCIENCE

COMPANY OF BIOLOGISTS LTD

Año: 2009 vol. 122 p. 3973 - 3982

0021-9533

Stress granules (SGs) and P-bodies (PBs) are related cytoplasmic structures harboring silenced mRNAs. SGs assemble transiently upon cellular stress, whereas PBs are constitutive and further induced by stress. Both foci are highly dynamic, with mRNPs and proteins rapidly shuttling in and out. Here we show that impairment of retrograde transport by knockdown of mammalian dynein heavy chain 1 (DHC1) or bicaudal D1 (BicD1) inhibits SG formation and PB growth upon stress, without affecting protein synthesis blockage. Conversely, impairment of anterograde transport by knockdown of kinesin heavy chain KIF5B or kinesin light chain 1 (KLC1) delayed SG dissolution. Strikingly, SG dissolution is not required to restore translation. Simultaneous knockdown of dynein and kinesin reverted the effect of single knockdowns on both SGs and PBs, suggesting that a balance between opposing movements driven by these molecular motors governs foci formation and dissolution. Finally, we found that regulation of SG dynamics by dynein and kinesin is conserved in Drosophila.