CARTS biogenesis requires VAP-lipid transfer protein complexes functioning at the endoplasmic reticulum-Golgi interface.
Vesicle-associated membrane protein-associated protein (VAP) is an endoplasmic reticulum (ER)-resident integral membrane protein that controls a nonvesicular mode of ceramide and cholesterol transfer from the ER to the Golgi complex by interacting with ceramide transfer protein and oxysterol-binding protein (OSBP), respectively. We report that VAP and its interacting proteins are required for the processing and secretion of pancreatic adenocarcinoma up-regulated factor, whose transport from the trans-Golgi network (TGN) to the cell surface is mediated by transport carriers called "carriers of the trans-Golgi network to the cell surface" (CARTS). In VAP-depleted cells, diacylglycerol level at the TGN was decreased and CARTS formation was impaired. We found that VAP forms a complex with not only OSBP but also Sac1 phosphoinositide phosphatase at specialized ER subdomains that are closely apposed to the trans-Golgi/TGN, most likely reflecting membrane contact sites. Immobilization of ER-Golgi contacts dramatically reduced CARTS production, indicating that association-dissociation dynamics of the two membranes are important. On the basis of these findings, we propose that the ER-Golgi contacts play a pivotal role in lipid metabolism to control the biogenesis of transport carriers from the TGN.
School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan.
Yuichi
Y
Wakana
School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan.
Richika
R
Kotake
School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan.
Nanako
N
Oyama
Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
Motohide
M
Murate
Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
Toshihide
T
Kobayashi
School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan.
Kohei
K
Arasaki
School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan.
Hiroki
H
Inoue
School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan tagaya@toyaku.ac.jp.
Mitsuo
M
Tagaya
D002518:Ceramides / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D037102:Lectins / Q000235:genetics / Q000378:metabolism; D008561:Membrane Fusion / Q000235:genetics; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D050683:R-SNARE Proteins / Q000235:genetics / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*; D021601:trans-Golgi Network / Q000235:genetics / Q000378:metabolism*
D002518:Ceramides; D036341:Intercellular Signaling Peptides and Proteins; D037102:Lectins; D050683:R-SNARE Proteins; C114051:VAPA protein, human; D033921:Vesicular Transport Proteins; C517340:ZG16B protein, human; D002784:Cholesterol; C119090:CERT1 protein, human; C089212:protein kinase D; D017346:Protein Serine-Threonine Kinases; D011493:Protein Kinase C