Rabbit Anti-Human GNA12 Polyclonal antibody

Frizzleds (FZDs) are unconventional G protein-coupled receptors, which activate diverse intracellular signaling pathways via the phosphoprotein Disheveled (DVL) and heterotrimeric G proteins. The Interaction interplay of FZDs with DVL and G proteins is complex, involves different regions of FZD and the potential dynamics are poorly understood. In the present study, we aimed to characterize the function of a highly conserved tyrosine (Y250(2.39)) in the intracellular loop 1 (ILl) of human FZD(4). We have found Y250(2.39) to be crucial for DVL2 interaction and DVL2 translocation to the plasma membrane. Mutant FZD4-Y250(2.39)F, impaired in DVL2 binding, was defective in both beta-catenin-dependent and beta-catenin-independent WNT signaling induced in Xenopus laevis embryos. The same mutant maintained interaction with the heterotrimeric G proteins Gan and G alpha(13) and was able to mediate WNT-induced G protein dissociation and G protein-dependent YAP/TAZ signaling. We conclude from modeling and dynamics simulation efforts that Y250(2.39) is important for the structural integrity of the FZD-DVL, but not for the FZD-G protein interface and hypothesize that the interaction network of Y250(2.39) and H348(4.46) plays a role in specifying downstream signaling pathways induced by the receptor.

Mutation of PKD1, encoding the protein polycystin-1 (PC1), is themain cause of autosomal dominant polycystic kidney disease (ADPKD). The signaling pathways downstream of PC1 in ADPKD are still not fully understood. Here, we provide genetic evidence for the necessity of G alpha 12 (encoded by Gna12, hereafter G alpha 12) for renal cystogenesis induced by Pkd1 knockout. There was no phenotype in mice with deletion of Ga12 (Ga12(-/-)). Polyinosine-polycytosine (pI: pC)-induced deletion of Pkd1 (Mx1Cre(+)Pkd1(f/f)G alpha 12(+/+)) in 1-week-old mice resulted in multiple kidney cysts by 9 weeks, but the mice with double knockout of Pkd1 and Ga12 (Mx1Cre(+)Pkd1(f/f)G alpha 12(-/-)) had no structural and functional abnormalities in the kidneys. These mice could survive more than one year without kidney abnormalities except multiple hepatic cysts in some mice, which indicates that the effect of G alpha 12 on cystogenesis is kidney specific. Furthermore, Pkd1 knockout promoted G alpha 12 activation, which subsequently decreased cell-matrix and cell-cell adhesion by affecting the function of focal adhesion and E-cadherin, respectively. Our results demonstrate that G alpha 12 is required for the development of kidney cysts induced by Pkd1 mutation in mouse ADPKD.