or and with dual emission filter sets for luminescence and fluorescence. Fluorescence of the YFP was acquired by exciting the samples at 485 nm and collecting the emission at 525 nm. The BRET ratios were calculated based on the ratio of emission from YFP and Rlu, as described previously. Saturation BRET studies were also performed as described previously. In brief, COS-1 cells were transfected with a fixed concentration of Rlu-tagged constructs as donor and with increasing concentrations of YFP-tagged constructs as acceptors. After 4872 h, BRET assays were performed. The BRET signals were plotted as ratios relative to the ratios of emissions of YFP/Rlu, and the curve fit was evaluated based on R2 values using Prism 4.0.. 1 and 3, C-terminal region of Frizzled receptors and three class B GPCRs. The IC loops and C-terminal region were predicted by the HMMTOP server and aligned by clustalW program. The conserved residues critical for activation of Wnt/b-catenin signaling are highlighted in yellow based on previous studies. Single mutations abolish Wnt/bcatenin signaling activity of human Frizzled 5 are indicated on the top of the alignment. Residue number corresponds to human Fz5 sequence. Supporting Information Acknowledgments We thank Jiandie Lin and Matthew Molusky at the University of Michigan for providing us with help in isolating primary liver cells from mice. We thank Alicja M. Ball and Mary-Lou Augustine for assistance with cell culture for the BRET studies. In addition, we thank David Nadziejka for editorial assistance in preparing the manuscript. Coexpression of Lrp5 enhanced the CRE Luciferase activity. HEK293 cells were transfected with GCGR or GCGRLrp5 plasmids along with CRE-Luc and TKRlu on day 1. Cells were left untreated or treated with 50 nM GCG1-29 on day 2. Cells were harvested on day 3 to measure the luciferase activity as described. After initial clinical descriptions, mutations in the alphagalactosidase A gene were found to be responsible for Fabry disease, which is an X-linked disorder of glycosphingolipid metabolism that results in progressive accumulation of neutral glycosphingolipids, in lysosomes, as well as other cellular compartments and the extracellular space. The prevalence of Fabry mutation ranges ” from 1 in 40,000 to 1:117,000 in United States and Australia to 1:833,000 in Northern Portugal, the majority of them Caucasians. 15950465” These figures may underestimate the real prevalence of the disease as many patients go undiagnosed due to rarity of this disorder and phenotypic variation of the clinical features, especially in females. Much higher estimates of prevalence have been obtained from a newborn screening project, most of which were so-called “late-onset”variants with some residual enzyme activity. Most affected males have little, if any, alpha-galactosidase A activity, and the deposition of GL-3 occurs primarily in vascular endothelial cells as well as epithelial and smooth muscle cells throughout the body. Early clinical manifestations of the disease include angiokeratoma, acroparesthesias, episodic pain “crises”, hypohydrosis, and AZ-3146 biological activity gastrointestinal 
complaints. Progressive GL-3 accumulation in the microvasculature and parenchyma leads to microvascular dysfunction, occlusion, and ischemia. Recent reports have described increased inflammation, oxidative stress, and circulating myeloperoxidase which appears to be associated with vasculopathic events. In adult males with Fabry disease, the renal, cardiovasc