The β 3 adrenergic receptor (β 3 AR) is the predominant β subtype in human brown adipocytes and is essential for regulating thermogenic lipolysis. To establish a novel experimental system for the biochemical analysis of this protein, we engineered several yeast strains. We show that the sterol background of the host strain greatly modulates the β 3 AR expression but not in the same way as it modulates the β 2 adrenergic receptor (β 2 AR), the other main studied adipocyte subtype. The human β 3 AR expressed in yeast is N-glycosylated but not phosphorylated. This latter characteristic distinguishes it from the β 2 AR. We showed that both β 2 AR and β 3 AR follow the secretory pathway to the yeast plasma membrane (PM) and are degraded in the vacuole. In the yeast strains used in this work, the two receptors also share a common mechanism of direct signal transduction through the yeast G α protein, Gpa1p. These strains thus appear to be useful for biochemical and structural studies of the human β 3 AR in an in vivo reconstitution system.