title: Functional analysis of the Ala67Thr polymorphism in agouti related protein associated with anorexia nervosa and leanness.
abstract: AgRP is a neuropeptide that stimulates food intake through inhibition of central melanocortin receptors (MCRs). In humans, the non-conservative amino acid substitution Alanine (Ala) 67 Threonine (Thr) has been associated with Anorexia Nervosa and with leanness. In the present study, the cellular distribution, processing and in vitro and in vivo activities of Ala67 and Thr67 AgRP were investigated. Western blots of media and lysates of BHK cells stably transfected with Ala67 or Thr67 expression constructs showed identical AgRP bands. Both Ala67 and Thr67 AgRP colocalised with the Golgi apparatus, but not with the ER or lysosomes when expressed in Att20 D16V cells. Also, no differences were observed between the potencies of bacterially expressed Ala67 and Thr67 AgRP to stimulate MC4R in a reporter gene assay or inhibit food intake in rats. Taken together, no evidence was found for a functional defect of Thr67 AgRP related to MC4R interactions.
authors.affiliation: Rudolf Magnus Institute of Neuroscience, Department of Pharmacology and Anatomy, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Corine E
authors.initials: CE
authors.lastname: de Rijke
authors.forename: Pilgrim J
authors.initials: PJ
authors.lastname: Jackson
authors.forename: Keith M
authors.initials: KM
authors.lastname: Garner
authors.forename: Rea J
authors.initials: RJ
authors.lastname: van Rozen
authors.forename: Nick R
authors.initials: NR
authors.lastname: Douglas
authors.forename: Martien J H
authors.initials: MJ
authors.lastname: Kas
authors.forename: Glenn L
authors.initials: GL
authors.lastname: Millhauser
authors.forename: Roger A H
authors.initials: RA
authors.lastname: Adan
mesh_terms: D054369:Agouti-Related Protein; D000409:Alanine / Q000235:genetics*; D000818:Animals; D000856:Anorexia Nervosa / Q000235:genetics*; D002460:Cell Line; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects / Q000235:genetics; D006801:Humans; D007276:Injections, Intraventricular; D036341:Intercellular Signaling Peptides and Proteins; D011110:Polymorphism, Genetic / Q000235:genetics*; D011506:Proteins / Q000008:administration & dosage / Q000235:genetics*; D051381:Rats; D017208:Rats, Wistar; D013851:Thinness / Q000235:genetics*; D013912:Threonine / Q000235:genetics*
chemical_list: C515198:AGRP protein, human; C515197:AGRP protein, rat; D054369:Agouti-Related Protein; D036341:Intercellular Signaling Peptides and Proteins; D011506:Proteins; D013912:Threonine; D000409:Alanine