Abstract
How the occupied KDEL receptor ERD2 is sorted into COPI vesicles for Golgi-to-ER transport is largely unknown. Here, interactions between proteins of the COPI transport machinery occurring during a "wave" of transport of a KDEL ligand were studied in living cells. FRET between CFP and YFP fusion proteins was measured by multifocal multiphoton microscopy and bulk-cell spectrofluorimetry. Ligand binding induces oligomerization of ERD2 and recruitment of ARFGAP to the Golgi, where the (ERD2)n/ARFGAP complex interacts with membrane-bound ARF1. During KDEL ligand transport, interactions of ERD2 with β-COP and p23 decrease and the proteins segregate. Both p24a and p23 interact with ARF1, but only p24 interacts with ARFGAP. These findings suggest a model for how cargo-induced oligomerization of ERD2 regulates its sorting into COPI-coated buds.
| Original language | English |
|---|---|
| Journal | Developmental Cell |
| Volume | 1 |
| Issue number | 1 |
| Pages (from-to) | 139-153 |
| Number of pages | 15 |
| ISSN | 1534-5807 |
| DOIs | |
| Publication status | Published - 07.2001 |
Funding
We thank Drs. Paul Luzio, Gottfried Mieskes, Richard Premont, Margaret Robinson, and Irene Schulz for kindly providing plasmids, Dr. Mariagrazia Pizza for the generous gift of CTX-K63, and Mr. Hartmut Sebesse and other members of our repro-division for help with image processing. We thank Martin Dale (Cambridge) for expert technical assistance and Drs. Quentin Hanley, Reinhard Jahn, Paul Luzio, Walter Nickel, Jim Pawley, Margaret “Scottie” Robinson, and Karin Römisch for helpful comments on the manuscript. This work was supported by grants from the Deutsche Forschungsgemeinschaft (So 43/60-1 and He-1977-2) given to H.-D.S. and S.W.H., respectively and the Fond der Chemischen Industrie given to H.-D.S. R.D. is a Senior Research Fellow of the Wellcome Trust (047578).
Research Areas and Centers
- Academic Focus: Center for Infection and Inflammation Research (ZIEL)
