This gene encodes a protein that binds to the tumor suppressor protein folliculin and to AMP-activated protein kinase (AMPK). The encoded protein participates in the regulation of cellular metabolism and nutrient sensing by modulating the AMPK and target of rapamycin signaling pathways. This gene has a closely related paralog that encodes a protein with similar binding activities. Both related proteins also associate with the molecular chaperone heat shock protein-90 (Hsp90) and negatively regulate its ATPase activity and facilitate its association with folliculin. [provided by RefSeq, Jul 2017]