Human ORP150/HSP12A Antibody

ORP150 (Oxygen-related protein of 150 kDa) is a member of the heat shock protein 70 family of molecules. Although the predicted MW is 111 kDa, it runs at 150 kDa in SDS-PAGE. The discrepancy may not be anomalous, since it is secreted into the ER lumen and likely to be glycosylated and/or phosphorylated. ORP150 is highly expressed in cells involved in secretion such as pancreatic acinar cells and hepatocytes. Mature human ORP150 is 967 amino acids (aa) in length. It contains two HSP70 signatures (aa 230‑243 and 380‑394) and an ER-retention signal (aa 996‑999). There are multiple isoforms. Three show alternate start sites at Met88, Met152, and a Met 44 aa upstream of the standard start site. Four isoforms also show deletions of aa 148‑958, 51‑59, 603‑664 and 164‑507, respectively. There is one 44 aa substitution for aa 603‑999. Over aa 1‑994, human ORP150 shares 92% aa identity with mouse ORP150.