Arl1p regulates spatial membrane organization at the trans-Golgi network through interaction with Arf-GEF Gea2p and flippase Drs2p

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 110; no. 8; pp. E668 - E677
• Main Authors: Tsai, Pei-Chin, Hsu, Jia-Wei, Liu, Ya-Wen, Chen, Kuan-Yu, Lee, Fang-Jen S.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 19.02.2013; National Acad Sciences
• Series: From the Cover
• Subjects: Adenosine diphosphate; ADP-Ribosylation Factors - metabolism; ADP-Ribosylation Factors - physiology; Biological Sciences; Calcium-Transporting ATPases - metabolism; Cell Membrane - metabolism; Cellular biology; enzymes; Fluorescent Antibody Technique, Indirect; Golgi apparatus; Guanine Nucleotide Exchange Factors - metabolism; Humans; lipids; Membrane Proteins - physiology; Membranes; Phosphatidylserines - metabolism; physiological transport; PNAS Plus; Protein Transport; RNA-protein interactions; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - metabolism; trans-Golgi Network - metabolism; Two-Hybrid System Techniques; Yeast; Yeasts
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.1221484110

ADP ribosylation factors (Arfs) are the central regulators of vesicle trafficking from the Golgi complex. Activated Arfs facilitate vesicle formation through stimulating coat assembly, activating lipid-modifying enzymes and recruiting tethers and other effectors. Lipid translocases (flippases) have been implicated in vesicle formation through the generation of membrane curvature. Although there is no evidence that Arfs directly regulate flippase activity, an Arf-guanine-nucleotide-exchange factor (GEF) Gea2p has been shown to bind to and stimulate the activity of the flippase Drs2p. Here, we provide evidence for the interaction and activation of Drs2p by Arf-like protein Arl1p in yeast. We observed that Arl1p, Drs2p and Gea2p form a complex through direct interaction with each other, and each interaction is necessary for the stability of the complex and is indispensable for flippase activity. Furthermore, we show that this Arl1p-Drs2p-Gea2p complex is specifically required for recruiting golgin Imh1p to the Golgi. Our results demonstrate that activated Arl1p can promote the spatial modulation of membrane organization at the trans -Golgi network through interacting with the effectors Gea2p and Drs2p.