Adapter protein involved in invadopodia and podosome formation and extracellular matrix degradation. Binds matrix metalloproteinases (ADAMs), NADPH oxidases (NOXs) and phosphoinositides. Acts as an organizer protein that allows NOX1- or NOX3-dependent reactive oxygen species (ROS) generation and ROS localization. Plays a role in mitotic clonal expansion during the immediate early stage of adipocyte differentiation. Interacts with NOXO1 (By similarity). Interacts (via SH3 domains) with NOXA1; the interaction is direct (By similarity). Interacts with ADAM15. Interacts with FASLG (By similarity). Cytoplasmic in normal cells and localizes to podosomes in SRC-transformed cells. Highly expressed in the stromal-vascular fraction of white adipose tissue with moderate expression in heart, skeletal muscle and the mature adipocyte fraction of white adipose tissue. Also expressed in brain, spleen, kidney and liver. Expressed in white and brown adipose tissues, eye, lung, heart, brain, spleen, stomach, liver and skeletal muscle (at protein level). Not expressed in kidney or bone marrow. Expression increases quickly after induction of adipocyte differentiation, reaches a maximum after 3 hours and decreases by 12 hours. Expressed from embryonic day 10.5 dpc in heart and hindbrain, followed by an increased expression at 12.5 dpc that also involves a subset of cells on the luminal side of the left ventricular wall in the case of the heart and neuroepithelium in the case of the brain. At 14.5 dpc, expression is present in developing bones (proximal ribs, lower jaw and clavicle), but the expression in the heart is no longer detectable. At stages 16.5 dpc and 18.5 dpc, strong expression is seen in the long bones of the limbs, particularly in the growth plates, as well as in the facial and cranial bones and the primordial incisor. Expression in the ribs is seen in the proximal regions in those areas where the transition from cartilage to bone is expected to occur. Expression in the eye at 16.5 dpc is highly specific for the ganglion cell layer. The PX domain is required for podosome localization because of its ability to bind phosphatidylinositol 3-phosphate (PtdIns(3)P) and phosphatidylinositol 3,4-bisphosphate (PtdIns(3,4)P2) and, to a lesser extent, phosphatidylinositol 4-phosphate (PtdIns(4)P), phosphatidylinositol 5-phosphate (PtdIns(5)P), and phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2). Binds to the third intramolecular SH3 domain (By similarity). Phosphorylated in SRC-transformed cells. Exhibit skeletal, cardiac and eye phenotypes. Mice have glaucoma and suffer growth retardation as well as craniofacial defects. Skeletons show marked kyphosis, poorly aligned teeth, anomalies in the iliac crest, and a prominent xiphisternum. Mice show loss of adipose tissue as well as cardiac deficiencies, such as dysmorphic ventricular chambers, thin mitral valves and immature and disarrayed trabeculae with frequent apical indentation. Mice show loss of ROS formation. Belongs to the SH3PXD2 family.