Membrane topology of NADPH-cytochrome P450 reductase on the endoplasmic reticulum.
Topology of the membrane-anchoring segment of mouse NADPH-cytochrome P450 reductase in the endoplasmic reticulum membrane was elucidated. An N-glycosylation site was generated in the amino-terminal hydrophilic sequence of the reductase, and the mutated protein was expressed in a cell-free system in the presence of microsomal vesicles. The in vitro synthesized reductase protein was integrated into the microsomal membrane and N-glycosylated depending on the presence of signal recognition particles. We conclude that the amino-terminal membrane-anchoring segment of the reductase is a type I signal-anchor sequence which shows amino-terminus-lumen and carboxy-terminus-cytoplasm topology.
Kida
Y
Y
Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-82, Japan.
Ohgiya
S
S
Mihara
K
K
Sakaguchi
M
M
D000595:Amino Acid Sequence; D000818:Animals; D004721:Endoplasmic Reticulum / Q000201:enzymology; D006031:Glycosylation; D008565:Membrane Proteins / Q000737:chemistry*; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis / Q000235:genetics; D009247:NADH, NADPH Oxidoreductases / Q000737:chemistry*; D009251:NADPH-Ferrihemoprotein Reductase; D010957:Plasmids / Q000235:genetics; D014176:Protein Biosynthesis / Q000235:genetics; D018271:Signal Recognition Particle / Q000502:physiology; D014908:Triticum / Q000201:enzymology
D008565:Membrane Proteins; D018271:Signal Recognition Particle; C503637:Srp72 protein, mouse; D009247:NADH, NADPH Oxidoreductases; D009251:NADPH-Ferrihemoprotein Reductase