Biochem/physiol Actions

Target Sub-Family: Ghrelin

GPCR Class: A

Protein Target: Ghrelin / GHSR-1a / growth hormone secretagogue receptor

Cell Line Description

GPCR Cell Lines

Host cells: Chem-1

Components

Pack contains 2 vials of mycoplasma-free cells, 1 ml per vial.Fifty (50) mL of Media Component.

General description

Millipore's Ready-to-Assay GPCR frozen cells are designed for simple, rapid calcium assays with no requirement for intensive cell culturing. Millipore has optimized the freezing conditions to provide cells with high viability and functionality post-thaw. The user simply thaws the cells and resuspends them in media, dispenses cell suspension into assay plates and, following over night recovery, assays for calcium response.

Ghrelin is a 28 amino acid peptide, containing a unique octanoyl moiety added post-translationally to Ser3, with diverse activities in the CNS, gastrointestinal tract, and cardiovascular system (Davenport et al., 2005; Leite-Moreira and Soares, 2007). In the CNS, ghrelin stimulates release of growth hormone from the anterior pituitary and increases appetite by binding to neurons within the arcuate nucleus. Circulating concentrations of ghrelin increase with preprandially and decrease post-prandially, and thus counterbalances the effects of leptin to coordinate energy balance, appetite and food intake. Ghrelin is also expressed in the cardiovascular system where it acts as a potent vasodilator; receptors are up-regulated in patients with atherosclerosis, suggesting that it plays a role in compensating for increased vasoconstriction (Kleinz et al., 2006). The effects of ghrelin are mediated by a Gq-coupled receptor, originally designated GHSR (growth hormone secretogogue receptor), and more recently termed the Ghrelin Receptor or GRLN. Two splice variants have been described; type 1a (GHS-R1a) is the functional receptor, whereas type 1b (GHS-R1b) encodes a truncated, inactive protein with only 5 transmembrane domains. As administration of agonists of the ghrelin receptor to rats leads to increased food intake and antagonists reduce food intake (Beck et al. 2004), antagonism and inverse agonism of the ghrelin receptor may reduce food intake in certain types of obesity, and agonists of the ghrelin receptor are potentially useful for treatment of anorexia and cachexia. Millipore's cloned human ghrelin-expressing cell line is made in the Chem-1 host, which supports high levels of recombinant ghrelin expression on the cell surface for functional detection via the calcium signaling pathway. Thus, the cell line is an ideal tool for screening for agonists, antagonists and modulators at Ghrelin Receptor.