ERp19 and ERp46, new members of the thioredoxin family of endoplasmic reticulum proteins.
Using a proteomic analysis of the luminal environment of the endoplasmic reticulum (ER), we have identified 141 proteins, of which 6 were previously unknown. Two newly discovered ER luminal proteins, designated ERp19 and ERp46, are related to protein disulphide isomerase. Western and Northern blot analyses revealed that both ERp19 and ERp46 and their respective mRNAs are highly expressed in the liver as compared with other tissues. Both proteins were enriched in purified liver ER vesicles and were localized specifically to the ER in McA-RH7777 hepatocytes. Functional analysis with yeast complementation studies showed that ERp46 but not ERp19 can substitute for protein disulphide isomerase function in vivo.
Knoblach
Barbara
B
Canadian Institutes of Health Research Membrane Protein Research Group and the Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7.
Keller
Bernd O
BO
Groenendyk
Jody
J
Aldred
Sandi
S
Zheng
Jing
J
Lemire
Bernard D
BD
Li
Liang
L
Michalak
Marek
M
D000595:Amino Acid Sequence; D000818:Animals; D018076:DNA, Complementary / Q000235:genetics; D015180:Electrophoresis, Gel, Two-Dimensional; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D008099:Liver / Q000378:metabolism / Q000648:ultrastructure; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D011490:Protein Disulfide Reductase (Glutathione); D019704:Protein Disulfide-Isomerases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013879:Thioredoxins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014018:Tissue Distribution
D018076:DNA, Complementary; D012333:RNA, Messenger; D013879:Thioredoxins; D011490:Protein Disulfide Reductase (Glutathione); C477009:TXNDC12 protein, human; D019704:Protein Disulfide-Isomerases; C480743:TXNDC5 protein, human