Detection of Human, Mouse, and Rat LMW‑PTP/ACP1 by Western Blot. |
Western blot shows lysates of SH‑SY5Y human neuroblastoma cell line, human placenta tissue, TF‑1 human erythroleukemic cell line, C2C12 mouse myoblast cell line, and Rat‑2 rat embryonic fibroblast cell line. PVDF membrane was probed with 1 µg/mL of Sheep Anti-Human/Mouse/Rat LMW‑PTP/ACP1 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF5075) followed by HRP-conjugated Anti-Sheep IgG Secondary Antibody (Catalog # HAF016). A specific band was detected for LMW‑PTP/ACP1 at approximately 18 kDa (as indicated). This experiment was conducted under reducing conditions and using Immunoblot Buffer Group 1.
LMW-PTP (Low Molecular Weight Protein Tyrosine Phosphatase; also Red cell acid phosphatase 1/ACP1, HCPTP, and HAAP/Adipocyte acid phosphatase) is a 17‑18 kDa member of the LMWPTP family, PTP superfamily of enzymes. It is widely expressed, being found in cells diverse as B and T cells, endothelial cells and vascular smooth muscle cells. LMW-PTP dephosphorylates multiple substrates, often in a cell-dependent manner. Among the substrates for LMW-PTP include PDGR beta, EphA2 and beta -catenin. PMW-PTP is found intracellularly, generally associated with two cytoplasmic pools, one in the cytosol and the other accompaning the cytoskeleton. Human LMW-PTP is 158 amino acids (aa) in length. The catalytic region spans aa 9-154, and there are two acetylation sites at Ala2 and Lys156. Phosphorylation on Tyr132 and Tyr133 occurs on cytoskeleton-associated LMW-PTP, and has the effect of increasing its phosphatase activity. There are three alternative splice variants reported for LMW-PTP. One shows a 34 aa substitution for aa 41-74, a second shows a deletion of aa 41-74, while a third contains a 35 aa substitution for aa 78-158. The last two isoforms may function a negative regulators of LMW-PTP activity. Full-length LMW-PTP shares 86% aa sequence identity with mouse LMW-PTP.