G Protein Alpha 12 (GNa12)

The predicted GNA12 protein contains 381 amino acids.Protein pull-down assays confirmed that G-alpha-12 interacted directly with alpha-SNAP in COS-7 and human umbilical vein endothelial cells (HUVECs). Domain-swapping experiments and mutation analysis showed that the first 37 N-terminal amino acids of G-alpha-12 and the convex surface of alpha-SNAP were necessary for the interaction. Cotransfection of HUVECs with G-alpha-12 and alpha-SNAP stabilized VE-cadherin (CDH5) at the plasma membrane, whereas downregulation of alpha-SNAP with small interfering RNA resulted in loss of VE-cadherin from the cell surface. Downregulation of alpha-SNAP in conjunction with G-alpha-12 overexpression decreased HUVEC endothelial barrier function.