Figure 1.

The constitutively active receptor GPR3 is the most cold-induced Gs-coupled GPCR in thermogenic adipose tissue

(A) Schematic depicting canonical ligand-dependent (solid line) versus hypothesized transcriptional control (dotted line) of Gs-coupled receptors in thermogenic adipocytes.

(B) Induction of Gs-coupled receptors in brown (left) and subcutaneous (right) white adipose depots during adaptation to cold. Statistical significance for each receptor at individual time points is indicated in Table S1 (BAT) and Table S2 (scWAT).

(C) cAMP accumulation in COS-7 cells transfected with increasing concentrations of GPR3 plasmid; gene expression data presented in log scale.

(D) Schematic depicting the bioluminescence resonance energy transfer (BRET) assay used to assess.

(E) G protein recruitment to wild-type (WT) and DRY-mutant GPR3.

(F) Scheme depicting the BRET assay used to assess.

(G–I) (G) cAMP levels produced by WT and N-terminal truncations of GPR3 and cAMP production induced by N-terminal GPR3 fragment aa18-27 on (H) WT GPR3 and (I) cannabinoid 1 receptor (CB1).

(J) Tissue panel of cold-induced fold changes in Gpr3 expression.

(K) Differential levels of cold-induced Gpr3 expression in BAT adipocytes (Ad) and stromal vascular fraction (SVF).

(L) In situ hybridization (ISH) of Gpr3 mRNA (red) in BAT of thermoneutral-housed or cold-challenged mice. Nuclei in BAT are stained with DAPI (blue).

For all panels, error bars represent ±SEM, p ≤ 0.05 = ∗, p ≤ 0.01 = ∗∗, p ≤ 0.001 = ∗∗∗, p ≤ 0.0001 = ∗∗∗∗, t test (K and J) or Bonferroni's multiple comparisons test (G). See also Figure S1.