Goldfish spexin: solution structure and novel function as a satiety factor in feeding control
| Autor: | Ivan K. Chu, Chi Kong Cho, Henry C. H. Law, Anderson O. L. Wong, Kong-Hung Sze, Matthew K. H. Wong, Ting Chen |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
medicine.medical_specialty
DNA Complementary Magnetic Resonance Spectroscopy Appetite control Physiology Endocrinology Diabetes and Metabolism Molecular Sequence Data Appetite Stimulants Neuropeptide Biology Polymerase Chain Reaction Satiety Response Eating Feeding behavior Goldfish Physiology (medical) Internal medicine medicine Animals Tissue Distribution Amino Acid Sequence Cloning Molecular Cells Cultured DNA Primers Brain Chemistry Circular Dichroism Neuropeptides Brain Postprandial Period Solution structure Endocrinology nervous system Data Interpretation Statistical sense organs Function (biology) |
| Zdroj: | American Journal of Physiology-Endocrinology and Metabolism. 305:E348-E366 |
| ISSN: | 1522-1555 0193-1849 |
| DOI: | 10.1152/ajpendo.00141.2013 |
| Popis: | Spexin (SPX) is a neuropeptide identified recently by bioinformatic approach. At present not much is known about its biological actions, and comparative studies of SPX in nonmammalian species are still lacking. To examine the structure and function of SPX in fish model, SPX was cloned in goldfish and found to be highly comparable with its mammalian counterparts. As revealed by NMR spectroscopies, goldfish SPX is composed of an α-helix from Gln5 to Gln14 with a flexible NH2 terminus from Asn1 to Pro4, and its molecular surface is largely hydrophobic except for Lys11 as the only charged residue in the helical region. In goldfish, SPX transcripts were found to be widely expressed in various tissues, and protein expression of SPX was also detected in the brain. In vivo feeding studies revealed that SPX mRNA levels in the telencephalon, optic tectum, and hypothalamus of goldfish brain could be elevated by food intake. However, brain injection of goldfish SPX inhibited both basal and NPY- or orexin-induced feeding behavior and food consumption. Similar treatment also reduced transcript expression of NPY, AgRP, and apelin, with concurrent rises in CCK, CART, POMC, MCH, and CRH mRNA levels in different brain areas examined. The differential effects of SPX treatment on NPY, CCK, and MCH transcript expression could also be noted in vitro in goldfish brain cell culture. Our studies for the first time unveil the solution structure of SPX and its novel function as a satiety factor through differential modulation of central orexigenic and anorexigenic signals. |
| Databáze: | OpenAIRE |
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