Format

Send to

Choose Destination
J Biol Chem. 2010 Oct 8;285(41):31616-33. doi: 10.1074/jbc.M110.154120. Epub 2010 Aug 3.

A protein interaction network for Ecm29 links the 26 S proteasome to molecular motors and endosomal components.

Author information

1
Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA.

Abstract

Ecm29 is a 200-kDa HEAT repeat protein that binds the 26 S proteasome. Genome-wide two-hybrid screens and mass spectrometry have identified molecular motors, endosomal components, and ubiquitin-proteasome factors as Ecm29-interacting proteins. The C-terminal half of human Ecm29 binds myosins and kinesins; its N-terminal region binds the endocytic proteins, Vps11, Rab11-FIP4, and rabaptin. Whereas full-length FLAG-Ecm29, its C-terminal half, and a small central fragment of Ecm29 remain bound to glycerol-gradient-separated 26 S proteasomes, the N-terminal half of Ecm29 does not. Confocal microscopy showed that Ecm-26 S proteasomes are present on flotillin-positive endosomes, but they are virtually absent from caveolin- and clathrin-decorated endosomes. Expression of the small central fragment of Ecm29 markedly reduces proteasome association with flotillin-positive endosomes. Identification of regions within Ecm29 capable of binding molecular motors, endosomal proteins, and the 26 S proteasome supports the hypothesis that Ecm29 serves as an adaptor for coupling 26 S proteasomes to specific cellular compartments.

PMID:
20682791
PMCID:
PMC2951235
DOI:
10.1074/jbc.M110.154120
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center