Adaptor γ Ear Homology Domain Conserved in γ-Adaptin and GGA Proteins That Interact with γ-Synergin

• Published in: Biochemical and biophysical research communications 2000-05, Vol.271 (3), p.719-725
• Main Authors: Takatsu, Hiroyuki, Yoshino, Kaori, Nakayama, Kazuhisa
• Format: Article
• Language: English
• Subjects: Adaptor Protein Complex 1; Adaptor Protein Complex gamma Subunits; Adaptor Proteins, Vesicular Transport; ADP-Ribosylation Factors; AGEH domain; Amino Acid Sequence; Biological Transport; Carrier Proteins - metabolism; clathrin adaptor; Cloning, Molecular; Conserved Sequence; Fluorescent Antibody Technique; g-adaptin; g-synergin; GGA protein; GGA proteins; Golgi Apparatus - metabolism; HeLa Cells; Hemagglutinins; Humans; Membrane Proteins - metabolism; Molecular Sequence Data; Oligopeptides; Peptides; Proteins; Sequence Alignment; trans-Golgi network; Transfection; VHS domain; Yeasts; γ-adaptin; γ-synergin
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.2000.2700

We identified a novel family of proteins that have a VHS domain and an AGEH (adaptor γ ear homology) domain that is homologous to the ear domain of the γ-adaptin subunit of the AP-1 clathrin adaptor. When overexpressed, the proteins, called GGA1, GGA2, and GGA3, localized to the trans-Golgi network (TGN) and often caused fragmentation and vacuolation of the compartment. Yeast two-hybrid analysis showed that the AGEH domains of the GGA proteins as well as those of γ-adaptins are able to interact with γ-synergin, which was previously shown to localized in the TGN region and interact with γ-adaptin. Furthermore, γ-synergin and either of the GGA proteins coexpressed were colocalized in the TGN region. These results suggest that the GGA proteins regulate the function of the TGN or membrane trafficking from this compartment and that the AGEH domains of GGAs and γ-adaptins, like the ear domain of α-adaptin, are involved in interaction with molecules that modulate their functions.