Oligomerization properties of ERp29, an endoplasmic reticulum stress protein.
ERp29, a novel and ubiquitously expressed endoplasmic reticulum (ER) stress-inducible protein, was recently isolated and cDNA cloned in our laboratory. Using size exclusion chromatography and chemical cross-linking we have assessed the oligomerization properties of ERp29. Purified ERp29 in solution as well as in rat hepatoma cells self-associates predominantly into homodimers. Labeling of the cells with [35S]methionine with subsequent cross-linking and immunoprecipitation showed that ERp29 interacts with a number of ER proteins, one of which was previously identified as BiP/GRP78. Secondary structure prediction and fold recognition methods indicate that the native conformation of ERp29 resembles the thioredoxin fold, a structural motif characteristic of a number of enzymes with the redox function, including protein disulfide isomerase (with which ERp29 shares limited sequence similarity). Dimerization of the protein is suggested to be advantageous for the protein binding potential of ERp29.
Division of Molecular Toxicology, Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden. soumkr@ki.se
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Mkrtchian
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Baryshev
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Matvijenko
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Sharipo
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Sandalova
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Schneider
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Ingelman-Sundberg
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Mkrtchiana
D000595:Amino Acid Sequence; D000818:Animals; D001704:Biopolymers; D002850:Chromatography, Gel; D003432:Cross-Linking Reagents / Q000737:chemistry; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014407:Tumor Cells, Cultured
D001704:Biopolymers; D003432:Cross-Linking Reagents; C110909:Erp29 protein, rat; D006360:Heat-Shock Proteins; D011994:Recombinant Proteins