1. A PH-like domain of the Rab12 guanine nucleotide exchange factor DENND3 binds actin and is required for autophagy.
- Author
-
Xu J, Kozlov G, McPherson PS, and Gehring K
- Subjects
- Actins chemistry, Actins genetics, Blood Proteins chemistry, Crystallography, X-Ray, Guanine Nucleotide Exchange Factors chemistry, Guanine Nucleotide Exchange Factors genetics, HEK293 Cells, Humans, Phosphoproteins chemistry, Phosphorylation, Protein Binding, Protein Conformation, Protein Domains, rab GTP-Binding Proteins chemistry, rab GTP-Binding Proteins genetics, Actins metabolism, Autophagy, Blood Proteins metabolism, Guanine Nucleotide Exchange Factors metabolism, Phosphoproteins metabolism, rab GTP-Binding Proteins metabolism
- Abstract
Rab GTPases are key regulators of membrane trafficking, and many are activated by guanine nucleotide exchange factors bearing a d ifferentially e xpressed in n ormal and n eoplastic cells (DENN) domain. By activating the small GTPase Rab12, DENN domain-containing protein 3 (DENND3) functions in autophagy. Here, we identified a structural domain (which we name PHenn) containing a pleckstrin homology subdomain that binds actin and is required for DENND3 function in autophagy. We found that a hydrophobic patch on an extended β-turn of the PHenn domain mediates an intramolecular interaction with the DENN domain of DENND3. We also show that DENND3 binds actin through a surface of positively charged residues on the PHenn domain. Substitutions that blocked either DENN or actin binding compromised the role of DENND3 in autophagy. These results provide new mechanistic insight into the structural determinants regulating DENND3 in autophagy and lay the foundation for future investigations of the DENN protein family., (© 2018 by The American Society for Biochemistry and Molecular Biology, Inc.)
- Published
- 2018
- Full Text
- View/download PDF