As the most common monogenic form of human obesity, about 130 naturally occurring melanocortin-4 receptor (MC4R) gene mutations have been identified. In this study, we reported detailed functional characterization of 10 novel human MC4R (hMC4R) mutants including R7C, C84R, S127L, S136F, W174C, A219V, P230L, F261S, I317V and L325F. Flow cytometry experiments showed that six mutants, including R7...

Mutations in the melanocortin-4 receptor (MC4R) gene are the most frequent monogenic causes of severe obesity. Most mutations have been described as heterozygous with loss of function, suggesting that haploinsufficiency is the most likely mechanism of dominant inheritance. We detected a heterozygous mutation, D90N, in a patient with severe early-onset obesity. Functional characterization of the...

The melanocortin-4 receptor (MC4R) is critical in regulating mammalian food intake and energy expenditure. Numerous mutations in the MC4R gene have been identified from obese humans. So far two naturally occurring porcine MC4R (pMC4R) mutations, D298N and R236H, have been identified from various strains of pigs and D298N is being utilized as a genetic marker to screen performance traits of pigs...

despite a quite short early history, computational drug design and discovery methods can now be efficient in reducing costs and speeding up drug developing procedure. melanocortin-4 receptor (mc4r) is a g protein-coupled receptor implicated in the regulation of body weight. despite its clinical reputation, there is a lack of in-depth knowledge about structure and behavior of mc4r in lipid bilay...

Melanocortin-4 receptor (Mc4r)-null mice exhibit late-onset obesity. To determine whether aberrant metabolism contributes to the obesity, food consumption by Mc4r-null mice was restricted to (pair-fed to) that consumed by wild-type (WT) mice. Pair-fed Mc4r-null females maintained body weights intermediate to that of WT and nonpair-fed Mc4r-null females, whereas pairfeeding normalized the body w...

Compulsive behavior is a debilitating clinical feature of many forms of neuropsychiatric disease, including Tourette syndrome, obsessive-compulsive spectrum disorders, eating disorders, and autism. Although several studies link striatal dysfunction to compulsivity, the pathophysiology remains poorly understood. Here, we show that both constitutive and induced genetic deletion of the gene encodi...

CONTEXT Whether mutations in the melanocortin-4 receptor (MC4R) are the cause of binge eating disorder was controversial. In addition, the penetrance of mutations in the MC4R in causing obesity was debated. OBJECTIVE We investigated whether MC4R variants identified from obese patients with binge eating disorder (T11A, F51L, T112M, and M200V) and variants identified in nonobese (I102T, F202L, ...

A chimeric protein comprised of melanocortin-4 receptor (MC4R) and the green fluorescent protein (GFP) was created for studying receptor/ligand localization and trafficking. The ligand binding affinities and second messenger stimulation induced by MC4R-GFP closely resembled those of the wild-type receptor, suggesting functional integrity of the chimeric protein. As observed with a confocal micr...

Phan, Loan K., Wendy K. Chung, and Rudolph L. Leibel. The mahoganoid mutation (Mgrn1) improves insulin sensitivity in mice with mutations in the melanocortin signaling pathway independently of effects on adiposity. Am J Physiol Endocrinol Metab 291: E611–E620, 2006. First published April 25, 2006; doi:10.1152/ajpendo.00034.2006.—Mahoganoid (Mgrn1) is a mutation of the mahogunin (Mgrn1) gene. Th...

BACKGROUND Feline diabetes mellitus (DM) shares many pathophysiologic features with human type 2 DM. Human genome-wide association studies have identified genes associated with obesity and DM, including melanocortin 4 receptor (MC4R), which plays an important role in energy balance and appetite regulation. HYPOTHESIS/OBJECTIVES To identify single nucleotide polymorphisms (SNPs) in the feline ...