Find in Library
Search millions of books, articles, and more
Indexed Open Access Databases
Functional Characterization of the Obesity-Linked Variant of the β<sub>3</sub>-Adrenergic Receptor
oleh: Esraa Haji, Saeed Al Mahri, Yumna Aloraij, Shuja Shafi Malik, Sameer Mohammad
Format: | Article |
---|---|
Diterbitkan: | MDPI AG 2021-05-01 |
Deskripsi
Adrenergic receptor β<sub>3</sub> (ADRβ<sub>3</sub>) is a member of the rhodopsin-like G protein-coupled receptor family. The binding of the ligand to ADRβ<sub>3</sub> activates adenylate cyclase and increases cAMP in the cells. ADRβ<sub>3</sub> is highly expressed in white and brown adipocytes and controls key regulatory pathways of lipid metabolism. Trp64Arg (W64R) polymorphism in the ADRβ<sub>3</sub> is associated with the early development of type 2 diabetes mellitus, lower resting metabolic rate, abdominal obesity, and insulin resistance. It is unclear how the substitution of W64R affects the functioning of ADRβ<sub>3</sub>. This study was initiated to functionally characterize this obesity-linked variant of ADRβ<sub>3</sub>. We evaluated in detail the expression, subcellular distribution, and post-activation behavior of the WT and W64R ADRβ<sub>3</sub> using single cell quantitative fluorescence microscopy. When expressed in HEK 293 cells, ADRβ<sub>3</sub> shows a typical distribution displayed by other GPCRs with a predominant localization at the cell surface. Unlike adrenergic receptor β<sub>2</sub> (ADRβ<sub>2</sub>), agonist-induced desensitization of ADRβ<sub>3</sub> does not involve loss of cell surface expression. WT and W64R variant of ADRβ<sub>3</sub> displayed comparable biochemical properties, and there was no significant impact of the substitution of tryptophan with arginine on the expression, cellular distribution, signaling, and post-activation behavior of ADRβ<sub>3</sub>. The obesity-linked W64R variant of ADRβ<sub>3</sub> is indistinguishable from the WT ADRβ<sub>3</sub> in terms of expression, cellular distribution, signaling, and post-activation behavior.