Mapping of the interface between leptin and the leptin receptor CRH2 domain.
Despite the impact of the leptin system on body weight and other physiologic processes, little is known about the binding of leptin to its receptor. The extracellular domain of the leptin receptor consists of two cytokine receptor homology (CRH) domains separated by an immunoglobulin-like domain, and followed by two juxtamembrane fibronectin type III modules. The CRH2 domain functions as a high-affinity binding site for leptin, and we previously demonstrated interaction with helices A and C of leptin. In this work, we constructed a homology model for the leptin/CRH2 complex and performed a detailed mutation analysis of the CRH2/leptin interface. Using both cell-based and in vitro binding assays using the isolated CRH2 domain, we show the critical role of hydrophobic interactions between Leu 13 and Leu 86 of leptin and Leu 504 in CRH2 in leptin binding and signalling. This binding pattern closely resembles the interaction of other four-helix bundle long chain cytokines with the CRH domain of their cognate receptors.
Iserentant
Hannes
H
Flanders Interuniversity Institute for Biotechnology, Department of Medical Protein Research (VIB09), Ghent University, Faculty of Medicine and Health Sciences, Baertsoenkaai 3, 9000 Ghent, Belgium.
Peelman
Frank
F
Defeau
Delphine
D
Vandekerckhove
Joël
J
Zabeau
Lennart
L
Tavernier
Jan
J
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D001665:Binding Sites / Q000235:genetics / Q000502:physiology; D001835:Body Weight / Q000235:genetics / Q000502:physiology; D019556:COS Cells; D002522:Chlorocebus aethiops; D006801:Humans; D020738:Leptin / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011485:Protein Binding / Q000235:genetics / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000235:genetics / Q000502:physiology; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D054411:Receptors, Leptin
C515448:LEPR protein, human; D020738:Leptin; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin