Certain G protein-coupled receptors (GPCRs)and their associated downstream signaling molecules have been localized to the caveolar region of mammalian cells. Interestingly, MCHR-1 has been isolated in fat cells which accumulate caveolin-1 and cholesterol as differentiation occurs. Our hypothesis is that altered MCHR-1 signaling contributes to the pathology of individuals with obesity, due to increases in adipose tissue and caveolae. The first goal of the project addressed the question of MCHR-1 localization to caveolae. To test this, caveolae were isolated via sucrose gradient ultracentrifugation. Fractionation and western blotting confirmed the presence of MCHR-1 within the caveolae. The second aim assessed ligand dependence on MCHR-1 localization. MCH exposure had no effect on receptor localization to caveolae lipid rafts within a ten-minute time course. Pharmacological disruption of caveolae by cholesterol depletion has been shown to enhance MCH-mediated ERK 1/2 activation, suggesting that caveolae may significantly impact the regulation of MCHR-1 signaling in cells.
|Presenters:||Elizabeth Delorme (Graduate Student)
Kelsi Robinson (Undergraduate Student)
|Time:||11 am (Session II)|