Technical Data
Endoplasmic Reticulum Protein 57 (ERp57, GRP58)
The Grps are induced by glucose or oxygen deprivation and by chemical compounds which perturb protein trafficking and secretion or calcium homeostasis. It has been reported (2) that the microsomal carnitine palmitoyl-transferase (CPT) seemed to be the protein that had been described previously as Grp58 (3), also known as Erp57, Erp61 (4), and HIP-70 (hormone-induced protein-70) (5). It has since been established that Erp61 and Grp58 are the same protein (6). CPT has a nuclear localization signal (7) and has been localized in the nucleus (8). It has been speculated (1) that in the nuclear microenvironment, by acting as a CPT, this protein modulates the levels of acyl-CoA and carnitine, both of which have been implicated in the regulation of gene transcription (911). It is also known that protein acylation-deacylation is crucial for the proper functioning of certain proteins and that this requires acyl-CoA (12). Reportedly oestrogen and leutenzing-hormone-releaseing hormone induce this 54kD protein ~100 fold in the hippocampus region of the brain (13). The presence in this protein of an apparent oestrogen-binding domain (14) and of two thioredoxin active-site sequences, CGHC, were recognized previously. Proteins with one or more CGHC sequence are classified as members of the thioredoxin superfamily (15). It remains to be seen how the possible interaction of the oestrogen-binding and CGHC domain, together with the CPT activity, link the diverse apparent functions ascribed to this protein.

Suitable for use in Western Blot. Other applications not tested.

Recommended Dilution:
Western Blot (ECL and Colorimetric): 1:500
Optimal dilutions to be determined by the researcher.

Storage and Stability:
May be stored at 4C for short-term only. For long-term storage, aliquot and store at -20C. Aliquots are stable for at least 12 months at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
25ul4C (-20C Glycerol)Blue IceRatRabbit
A 54kD ERp57 (Grp58) from rat liver.
Supplied as a liquid, before the addition of glycerol to 40%.
Detects a n~57kD protein, corresponding to the apparent molecular mass of Erp57 on SDS-PAGE immunoblots, in samples from human, monkey, mouse, rat, porcine, hamster, guinea pig, rabbit, canine and bovine. Strong reactivity with recombinant human, mouse and rat Erp57 proteins is seen.
Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.
1. Murthy, M.S.R., and Pande, S.V. (1994) Biochem J. 304:31-34. 2. Murthy, M.S.R., and Pande, S.V. (1993) Mol. Cell. Biochem. 122:133-138. 3. Lee, A.S. (1981) J. Cell. Physiol. 106:119-125. 4. Mazzarella, R.A., et al., (1990) J. Biol. Chem. 265:1094-1101. 5. Kaplitt, M.G., et al., (1993) Endocrinology (Baltimore) 133:99-104. 6. Mazzarella, R.A., et al., (1994) Arch. Biochem. Biophys. 308:454-460. 7. Alteri, F., et al., (1993) Biochem. Biophys. Res. Commun. 194:992-1000. 8. Ohtani, H., et al., (1993) Histochemistry 100:423-429. 9. Henry, M.F., and Cronan, J.E., Jr. (1992) Cell 70:671-679. 10. DiRusso, C.C., Heimert, T.L., and Metzer, A.K. (1992) J. Biol. Chem. 267:8685-8691. 11. Roncero, C. and Goodridge, A. (1992) J. Biol. Chem. 267:14918-14927. 12. Camp, L.A. and Hoffmann, S.L. (1993) J. Biol. Chem. 268:22566-22574. 13. Mobbs, C.V., Fink, G., and Pfaff, D.W. (1990) Science 247:1477-1479. 14. Barker, W.C., et al., (1990) Science 249:566-567. 15. Nigam, S.K., et al., (1994) J. Biol. Chem. 269:1744-1749.