Proteinuria is one of the hallmarks of kidney disease. Serum proteins such as albumin are prevented from being filtered into the urine by the glomerular filtration barrier of which podocytes are a key part. Podocyte structure and function are dependent on maintenance of the actin cytoskeleton in podocyte foot processes. Foot processes contain two structural and signaling hubs: the slit diaphragm and focal adhesions, both of which maintain foot process integrity and relay signals to and from the podocyte exterior in response to hemodynamic changes. The entry below describes the key components of foot process actin cytoskeleton structure and regulation.