Research Paper Volume 2, Issue 11 pp 823—842

Figure 5. STAT3-mitochondrial localization and mitochondria morphology. (A) Intracellular localization of Stat3. Sub-cellular fractions were isolated and protein extracts were prepared as described in M&M. Western blot analysis was performed using antibodies against STAT3, and VDAC-1 or β-TUBULIN were used as mitochondrial and cytoplasmic markers, respectively. Tot, whole unfractionated extract; Cyto, cytoplasmic fraction; Mito, mitochondrial fraction. (B) Effects of expressing a mitochondria targeted STAT3 form (MTS-Stat3) on mitochondrial Ca²⁺ homeostasis. MEFs were co-transfected with mitochondria-targeted aequorin (AEQ) and MTS-Stat3, and AEQ measured upon challenging with 100 μM ATP. Traces are representative of at least 10 from 3 independent experiments yielding similar results. (C) Mitochondrial morphology was visualized by loading MEFs with 10 nM TMRM. The field of cells is representative of > 50 observations from 2 independent experiments.