Figure 6.

Signaling networks of the βARs in adipocytes. Each of the three βARs is able to activate similar pathways: PKA, ERK, and p38 MAPK. However the order and number of steps involved varies, such that β₃AR represents what we term “concurrent” coupling to Gs vs. Gi, vs. the β₂AR type of “processive” coupling. Less is known about the details of β₁AR. Because β₁AR also contains one of the PXXP motifs as in β₃AR, but it is also phosphorylated, we have provisionally termed in “mixed-mode” coupling. The shaded gray arrows point to subsequent downstream cellular effects.