Figure 4.

Gα12 mutants unable to activate Rho lead to mitochondrial fragmentation and to an increased mitochondrial permeability. HUVECs were transfected with the Myc-tagged Gα12Q226L, Gα12Q229L-Δp115^RhoGEF, Gα12Q229L,R6A-Δp115^RhoGEF, and Gα12Q229L A (with residues 4–8 replaced with a NAAIR sequence; ref. 27; constructs as indicated). A) 24 h after transfection, cells were incubated with MitoTracker, fixed, and immunostained with Myc-specific antibody. Scale bars = 20 μM. B) MitoTracker-labeled mitochondria in transfected and surrounding untransfected cells were quantified using ImageJ. Fifteen transfected cells for each Gα12 mutant were analyzed. Error bars indicate sd.