Inefficient targeting to the endoplasmic reticulum by the signal recognition particle elicits selective defects in post-ER membrane trafficking

Article Article scientifique Article Inefficient targeting to the endoplasmic reticulum by the signal recognition particle elicits selective defects in post-ER membrane trafficking eng 2007 author Lakkaraju Asvin K K. author Luyet Pierre-Philippe 504603 author Parone Philippe 528921 author Falguieres Thomas 627917 author Strub Katharina 27661 834-847 10.1016/j.yexcr.2006.12.003 17239854 0014-4827 The signal recognition particle (SRP) is required for protein translocation into the endoplasmic reticulum (ER). With RNA interference we reduced its level about ten-fold in mammalian cells to study its cellular functions. Such low levels proved insufficient for efficient ER-targeting, since the accumulation of several proteins in the secretory pathway was specifically diminished. Although the cells looked unaffected, they displayed noticeable and selective defects in post-ER membrane trafficking. Specifically, the anterograde transport of VSV-G and the retrograde transport of the Shiga toxin B-subunit were stalled at the level of the Golgi whereas the endocytosed transferrin receptor failed to recycle to the plasma membrane. Endocytic membrane trafficking from the plasma membrane to lysosomes or Golgi was undisturbed and major morphological changes in the ER and the Golgi were undetectable at low resolution. Selective membrane trafficking defects were specifically suppressed under conditions when low levels of SRP became sufficient for efficient ER-targeting and are therefore a direct consequence of the lower targeting capacity of cells with reduced SRP levels. Selective post-ER membrane trafficking defects occur at SRP levels sufficient for survival suggesting that changes in SRP levels and their effects on post-ER membrane trafficking might serve as a mechanism to alter temporarily the localization of selected proteins. Cells, Cultured Endoplasmic Reticulum/metabolism Hela Cells Humans Membrane Proteins/metabolism Models, Biological Protein Transport RNA Interference Signal Recognition Particle/antagonists & inhibitors/physiology Transport Vesicles/physiology Dewey 570 46 Département de biologie cellulaire 165 false Experimental cell research 313 4 eb424b7b-23d3-4849-b27c-41322c19e5ad Article (Published version) Restricted fulltext.pdf 1349216 application/pdf restrictedAccess Faculté des sciences / Section de biologie / Département de biologie cellulaire

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Inefficient targeting to the endoplasmic reticulum by the signal recognition particle elicits selective defects in post-ER membrane trafficking	Experimental cell research			2007	636	1

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Falguieres, Thomas