RT Journal Article
SR Electronic
T1 COPI mediates recycling of an exocytic SNARE from endosomes by recognition of a ubiquitin sorting signal
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 133546
DO 10.1101/133546
A1 Peng Xu
A1 Hannah M. Hankins
A1 Chris Macdonald
A1 Samuel J. Erlinger
A1 Meredith N. Frazier
A1 Nicholas S. Diab
A1 Robert C. Piper
A1 Lauren P. Jackson
A1 Jason A. MacGurn
A1 Todd R. Graham
YR 2017
UL http://biorxiv.org/content/early/2017/05/03/133546.abstract
AB The COPI coat forms transport vesicles from the Golgi complex and plays a poorly defined role in endocytic trafficking. Here we show that COPI mediates delivery of a budding yeast SNARE (Snc1) from early endosomes to the Golgi complex through recognition of a polyubiquitin sorting signal. Snc1 is a v-SNARE that drives fusion of exocytic vesicles with the plasma membrane, and then recycles through early endosomes back to the Golgi for reuse. Removal of ubiquitin from Snc1, or deletion of a β’-COP subunit propeller domain that binds K63-linked polyubiquitin, causes aberrant accumulation of Snc1 in early endosomes. Moreover, replacement of the β’-COP propeller domain with unrelated ubiquitin-binding domains restores Snc1 recycling. These results indicate that ubiquitination, a modification well known to target membrane proteins to the lysosome or vacuole for degradation, can also function as recycling signal to sort a SNARE into COPI vesicles at early endosomes for Golgi delivery.