MTSEA prevents ligand binding to the human melanocortin-4 receptor by modification of cysteine 130 in transmembrane helix 3

Alan Cox, Dan Donnelly, Manminder Kaur, Sharon C. Cheetham, Victor B. Cockcroft, John B C Findlay

    Research output: Contribution to journalArticlepeer-review

    Abstract

    We have investigated the effect of the sulfhydryl-reactive reagent, methyl thiosulfonate ethylammonium (MTSEA), on ligand binding to the human melanocortin-4 (MC4) receptor stably expressed in HEK-293 cells. MTSEA inhibited binding of the agonist, 125I-NDPα-MSH, and the antagonist, 125I-SHU9119, in a concentration-dependent manner. Pre-incubation of cells with either the agonist or antagonist protected from subsequent MTSEA inhibition of radioligand binding. Mutation of Cys130 in transmembrane helix 3 to alanine, whilst not affecting ligand binding, led to a complete loss of the inhibitory effect of MTSEA. Since other types of sulfhydryl-reactive reagents had no effect on ligand binding, we conclude that covalent modification of Cys130 by MTSEA disrupts ligand binding by neutralising a close-by negative charge, most likely on Asp126. © 2004 Published by Elsevier B.V. on behalf of the Federation of European Biochemical Societies.
    Original languageEnglish
    Pages (from-to)285-291
    Number of pages6
    JournalFEBS Letters
    Volume579
    Issue number1
    DOIs
    Publication statusPublished - 3 Jan 2005

    Keywords

    • α-MSH
    • G protein-coupled receptor
    • Melanocortin-4 receptor
    • MTSEA

    Fingerprint

    Dive into the research topics of 'MTSEA prevents ligand binding to the human melanocortin-4 receptor by modification of cysteine 130 in transmembrane helix 3'. Together they form a unique fingerprint.

    Cite this