Formation of COPI-coated vesicles at a glance

Abstract

The Key panel of the poster and of the accompanying slides 1-5 contained an incorrect label. The correct label is:This has now been corrected online.We apologise for any confusion this error might have caused.β/γ-Arf1

Regulation of cargo export and sorting at the trans‐Golgi network

“…After reaching the ER–Golgi intermediate compartment, cargoes are transported to the Golgi complex, where they enter the cis‐Golgi, proceed towards the TGN and glycosylation takes place . Cargo proteins move from the cis to the trans site of the Golgi within maturing cisternae while ER‐ and Golgi‐resident proteins move back in COPI vesicles . After reaching the TGN, cargoes are sorted in different carriers, often tubular/pleiomorphic, to their final destinations, such as the lysosomes, the plasma membrane, or the secretory granules (in specialized cells) .…”

Multiple features within the syntaxin Sed5p mediate its Golgi localization

“…To date, relatively few N‐terminal COPI‐binding motifs have been characterized . In mammalian cells, some Golgi resident glycosyltransferases have been shown to directly interact with coatomer however the motif that mediates this association—“ϕ‐(K/R)‐X‐L‐X‐(K/R)”—is not similar to the motif we have identified in Sed5p (Figure ).…”

“…To date, relatively few N-terminal COPI-binding motifs have been characterized. 3,7,49 In mammalian cells, some Golgi resident glycosyltransferases have been shown to directly interact with coatomer 7 however the motif that mediates this association-"ϕ-(K/R)-X-L-X-(K/R)"-is not similar to the motif we have identified in Sed5p ( Figure 2). The COPI-coatomer binding motif from Sed5p is also able to mediate binding to mammalian coatomer, and thus a binding site for N-terminal tribasic motifs on COPI-coatomer would seem to be an evolutionarily conserved feature.…”

“…While the mechanism of retention mediated by the TMD of SNAREs and other type II membrane proteins have been proposed, 35 and the role of sorting motifs in mediating coat interactions are well established, 49,69 less is known about how the folded-back conformation of SNAREs, and syntaxins in particular, would facilitate organelle retention/membrane trafficking. 18,20 We have shown here that Sed5p's Golgi-ER transport is apparently independent of COPI func- For temperature shift experiments that lasted less than 10 minutes, 0.5 mL of early-log phase cells (OD 660 =~0.5) were aliquoted into 1.5 mL microcentrifuge tubes, which were then incubated in a 37 C water bath for the indicated periods to achieve rapid temperature change.…”

A paralog-specific role of the COPI pathway in the neuronal differentiation of murine pluripotent cells

“…The Copg2 and Copz2 genes, paralogous to Copg1 and Copz1, were discovered two decades ago 3,4 . Since then, it has been an outstanding question whether unique functions can be ascribed to COPI paralogous proteins 38,39,40 . Recombinant coatomer complexes that contain either g1-COP or g2-COP are equally efficient in producing COPI vesicles from purified Golgi membranes 41 The COPI pathway is essential for life and depletion of non-paralogous COP subunits is lethal in mammalian cells 42,43 .…”