Nordihydroguaiaretic acid blocks protein transport in the secretory pathway causing redistribution of Golgi proteins into the endoplasmic reticulum.
We have investigated the effect of nordihydroguaiaretic acid (NDGA), an inhibitor of lipoxygenase, on the intracellular protein transport and the structure of the Golgi complex. Pulse-chase experiments and immunoelectron microscopy showed that NDGA strongly inhibits the transport of newly synthesized secretory proteins to the Golgi complex resulting in their accumulation in the endoplasmic reticulum (ER). Despite their retention in the ER, oligosaccharides of secretory and ER-resident proteins were processed to endoglycosidase H-resistant forms, raising the possibility that oligosaccharide-processing enzymes are redistributed from the Golgi to the ER. Morphological observations further revealed that alpha-mannosidase II (a cis/medial-Golgi marker), but not TGN38 (a trans-Golgi network marker), rapidly redistributes to the ER in the presence of NDGA, resulting in the disappearance of the characteristic Golgi structure. Upon removal of the drug, the Golgi complex was reassembled into the normal structure as judged by perinuclear staining of alpha-mannosidase II and by restoration of the secretion. These effects of NDGA are quite similar to those of brefeldin A. However, unlike brefeldin A, NDGA did not cause a dissociation of beta-coatomer protein, a subunit of coatomer, from the Golgi membrane. On the contrary, NDGA exerted the stabilizing effect on beta-coatomer protein/membrane interaction against the dissociation caused by brefeldin A and ATP depletion. Taken together, these results indicate that NDGA is a potent agent disrupting the structure and function of the Golgi complex with a mechanism different from those known for other drugs reported so far.
Fujiwara
T
T
Department of Biochemistry, Fukuoka University School of Medicine, Jonan-ku, Fukuoka 814-80, Japan.
Takami
N
N
Misumi
Y
Y
Ikehara
Y
Y
D000255:Adenosine Triphosphate / Q000378:metabolism; D000418:Albumins / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D019556:COS Cells; D002478:Cells, Cultured; D020756:Coatomer Protein; D003176:Complement C3 / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D009637:Masoprocol / Q000494:pharmacology*; D008565:Membrane Proteins / Q000378:metabolism; D009844:Oligosaccharides / Q000378:metabolism; D011228:Prealbumin / Q000378:metabolism; D011480:Protease Inhibitors / Q000378:metabolism
D000418:Albumins; D020756:Coatomer Protein; D003176:Complement C3; D008565:Membrane Proteins; D009844:Oligosaccharides; D011228:Prealbumin; D011480:Protease Inhibitors; D009637:Masoprocol; D000255:Adenosine Triphosphate