Clara Cell Protein, Recombinant, Human (CC16, CC10, Uteroglobin, Urinary Protein 1, Clara Cell Secretory Protein)

Uteroglobin, also called Clara cell secretory, phospholipid binding, 10kD or 16kD protein (CCSP, CCPBP, CC10 or CC16, respectively) is a small, non-glycosylated secreted protein of the secretoglobin superfamily, (designated 1A, member 1).1-3 Its name is derived from its very high expression in the pre-implantation uterus. It is produced by the non-ciliated, non-mucous secretory cells that predominate in lung bronchioles (Clara cells), and other non-ciliated epithelia that communicate with the external environment.1-3 Expression is induced by steroid hormones such as estrogen, and enhanced by the non-steroid hormone prolactin.1 Uteroglobin is found in blood, urine and other body fluids.1 Human Uteroglobin cDNA encodes a 21 amino acid (aa) signal sequence and a 70 aa mature protein. It shares 53-56% aa identity with mouse, rat, bovine, canine, equine or rabbit Uteroglobin, and is active in mice.4 The mature protein forms a disulfide-linked head-to-tail homodimer of 16kD. 2, 5 This homodimer is thought to form a binding pocket that binds hydrophobic ligands such as phospholipids, progesterone and retinols.5 Sequestering of prostaglandins and leukotrienes is anti-inflammatory, while sequestering of carcinogens such as polychlorinated bisphenols is anti-tumorigenic.6-8 Other immunoregulatory activities of Uteroglobin include cell migration inhibition (by binding the chemotaxis-related formyl peptide receptor FPR2 on dendritic cells), and the inhibition of T cell differentiation to a Th2 phenotype.9 A single nucleotide polymorphism of Uteroglobin, A38G, confers increased risk of asthma.10 Transglutaminase can crosslink Uteroglobin, either to itself or to other proteins such as the adhesion molecule fibronectin.3, 11 Binding of fibronectin to Uteroglobin in the kidney is thought to protect against nephropathy, while binding of the lipocalin-1 receptor has been reported to suppress cancer cell motility and invasion.12, 13 Molecular Weight: Predicted: 8kD (monomer) Activity: Measured by the ability of the immobilized protein to support the adhesion of the A549 human lung carcinoma cell line. The ED50 for this effect is typically 1-5ug/ml.. Storage and Stability: Lyophilized powder may be stored at -20 degrees C. Stable for 12 months at -20 degrees C. Reconstitute with sterile PBS. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Reconstituted product is stable for 6 months at -20 degrees C. 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.