Component of the TSC-TBC complex, that contains TBC1D7 in addition to the TSC1-TSC2 complex and consists of the functional complex possessing GTPase-activating protein (GAP) activity toward RHEB in response to alterations in specific cellular growth conditions. The small GTPase RHEB is a direct activator of the protein kinase activity of mTORC1 and the TSC-TBC complex acts as a negative regulator of mTORC1 signaling cascade by acting as a GAP for RHEB. Participates in the proper sensing of growth factors and glucose, but not amino acids, by mTORC1. It is unclear whether TBC1D7 acts as a GTPase-activating protein and additional studies are required to answer this question. Component of the TSC-TBC complex (also named Rhebulator complex), composed of the TSC1-TSC2 heterodimer and TBC1D7. Interacts with TSC1 (via C-terminal half of the coiled-coil domain). Localizes in the cytoplasmic vesicles of the endomembrane in association with TSC1-TSC2 complex. Highly expressed in heart, and slightly in kidney, liver and placenta. The disease is caused by variants affecting the gene represented in this entry. Was initially identified as a negative regulator of the TSC1-TSC2 complex (PubMed:17658474). However, it was later shown that TBC1D7 is part of the TSC-TBC complex and participates in GTPase-activating protein activity, leading to inhibition of the TOR signaling cascade (PubMed:22795129). The differences between 2 reports might be explained by experimental conditions in the initial report, in which they overexpressed the TBC1D7 subunit, possibly leading to disrupt the stoichiometric complex and its downstream functions.