CaBP2 is a rat homolog of ERp72 with proteindisulfide isomerase activity.
Ca-binding protein 2 (CaBP2) has been described previously as an intracisternal calcium-binding microsomal glycoprotein. We report now the primary sequence of this protein as deduced from the corresponding cDNA. The protein possesses a C-terminal -KEEL retention sequence and three repeats of the thioredoxin-like motive -EFYAPNCGHCK-, and represents the rat homolog of ERp72. In contrast to earlier reports on ERp72, CaBP2 possesses significant proteindisulfide isomerase activity. Furthermore, in contrast to ERp72, CaBP2 is a glycoporotein containing O-linked glycans. The amount of CaBP2 in H-35 Reuber hepatoma cells increases in parallel with that of immunoglobin heavy-chain-binding protein under conditions which lead to impaired glycosylation, while the amount of calreticulin, another KDEL-containing glycoprotein, remains almost unchanged.
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Abteilung Klinische Biochemie, Zentrum Innere Medizin, Universität Göttingen, Germany.
Rupp
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Lampen
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Söling
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002135:Calcium-Binding Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D003001:Cloning, Molecular; D015723:Gene Library; D007328:Insulin / Q000378:metabolism; D007535:Isomerases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000502:physiology; D008114:Liver Neoplasms, Experimental / Q000378:metabolism*; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D008715:Methionine / Q000378:metabolism; D008862:Microsomes, Liver / Q000378:metabolism*; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D019704:Protein Disulfide-Isomerases; D051381:Rats; D017208:Rats, Wistar
D002135:Calcium-Binding Proteins; D007328:Insulin; D008562:Membrane Glycoproteins; D009838:Oligodeoxyribonucleotides; C062477:endoplasmic reticulum glycoprotein p72; D008715:Methionine; D007535:Isomerases; D019704:Protein Disulfide-Isomerases