Project Summary Experiments proposed in this K01 aim to investigate a novel role of PAK1 in the regulation of cardiac function and adipose tissue homeostasis in female mice. The specific aims are: Aim #1 To investigate the mechanisms by which estrogens regulate PAK1 in the heart and adipose tissue. Aim #2: To investigate the mechanisms by which PAK1 regulates cardiac function in female mice. Aim #3: To investigate the mechanisms by which PAK1 regulates adipose tissue homeostasis in female mice and the effect of its dysregulation on cardiac function. The scope of the research planned for this supplement is to study the effects of FTY720 (fingolimod) in a model of heart failure linked to obesity and hypertension.