Back to Search Start Over

Clathrin Functions in the Absence of the Terminal Domain Binding Site for Adaptor-associated Clathrin-Box Motifs

Authors :
Linton M. Traub
Alex Merz
Douglas R. Boettner
Sandra K. Lemmon
Isabel María Fernández-Golbano
María Isabel Geli
John R. Collette
Richard J. Chi
Rachael L. Plemel
Source :
Molecular Biology of the Cell. 20:3401-3413
Publication Year :
2009
Publisher :
American Society for Cell Biology (ASCB), 2009.

Abstract

Clathrin is involved in vesicle formation in the trans-Golgi network (TGN)/endosomal system and during endocytosis. Clathrin recruitment to membranes is mediated by the clathrin heavy chain (HC) N-terminal domain (TD), which forms a seven-bladed β-propeller. TD binds membrane-associated adaptors, which have short peptide motifs, either the clathrin-box (CBM) and/or the W-box; however, the importance of the TD binding sites for these motifs has not been tested in vivo. We investigated the importance of the TD in clathrin function by generating 1) mutations in the yeast HC gene (CHC1) to disrupt the binding sites for the CBM and W-box (chc1-box), and 2) four TD-specific temperature-sensitive alleles of CHC1. We found that TD is important for the retention of resident TGN enzymes and endocytosis of α-factor; however, the known adaptor binding sites are not necessary, because chc1-box caused little to no effect on trafficking pathways involving clathrin. The Chc1-box TD was able to interact with the endocytic adaptor Ent2 in a CBM-dependent manner, and HCs encoded by chc1-box formed clathrin-coated vesicles. These data suggest that additional or alternative binding sites exist on the TD propeller to help facilitate the recruitment of clathrin to sites of vesicle formation.

Details

ISSN :
19394586 and 10591524
Volume :
20
Database :
OpenAIRE
Journal :
Molecular Biology of the Cell
Accession number :
edsair.doi.dedup.....eed3aa7a1c1c811bd2d0e2b382a5afcf