Application Methods: Immunoprecipitation, Western Blotting
Background: Na+/H+ exchanger regulatory factor (NHERF1 or EBP-50) is one of several related PDZ domain-containing proteins (1). NHERF1 was first identified as a necessary cofactor for cyclic AMP-associated inhibition of Na+/ H+ exchanger isoform 3 (NHE3) (2). NHERF1 is a multifunctional adaptor protein that interacts with receptors and ion transporters via its PDZ domains, and with the ERM family of proteins, including merlin, via its carboxy-terminus (2,3). NHERF1 may play an important role in breast cancer. Estrogen has been found to induce NHERF1 in estrogen receptor-positive breast cancer cells (2,3). Furthermore, NHERF1 has been shown to bind to PDGFR, which is activated in breast carcinomas. NHERF1 has been found to promote the formation of a ternary complex containing PTEN, NHERF1, and PDGFR. Therefore, NHERF1 may function to recruit PTEN to PDGFR to inhibit the activation of PI3K/Akt signaling in normal cells; this mechanism may be disrupted in cancer (4). NHERF1 also binds to the cystic fibrosis transmembrane conductance regulator (CFTR), which functions as an ion channel and has disease-causing mutations in cystic fibrosis (5). Other proposed functions of NHERF1 include testicular differentiation, endosomal recycling, membrane targeting, protein sorting, and trafficking (6).
Application Methods: Immunofluorescence (Frozen)
Background: Vasopressin is a neuroendocrine peptide that is released to the circulation by magnocellular neurons whose cell bodies are mainly found in the paraventricular and the supraoptic nuclei of the hypothalamus. It was first isolated from pituitary gland extracts and synthesized in 1951 (1). Vasopressin acts by activating G protein-coupled, V1a, V1b (also known as V3) and V2 receptors and plays a fundamental role in the maintenance of water homeostasis. One of its main functions is body water retention (2), hence its alternative name antidiuretic hormone or ADH. Vasopressin also leads to increased arterial blood pressure by raising peripheral vascular resistance (3). Vasopressin is also involved in other physiological processes such as acute heart failure (4), pain (5), and metabolic syndrome (6).