| Primary Identifier | IPR037520 | Type | Domain |
| Short Name | Folliculin/SMCR8_longin |
| description | Folliculin (FLCN) is a tumor suppressor that enables nutrient-dependent activation of the mechanistic target of rapamycin complex 1 (mTORC1) protein kinase via its guanosine triphosphatase (GTPase) Activating Protein (GAP) activity. It belong to the DENN module family of proteins and contains a divergent DENN module comprised of a N-terminal longin domain (also known as upstream DENN domain, u-DENN), followed by a DENN domain. It forms a complex with its partners, FNIP1 or FNIP2 (Folliculin interacting protein 1 or 2), which directly contacts the Rag GTPases RagC/D to stimulate GTP hydrolysis and thus promote the conversion to the GDP-bound state. FLCN-FNIP2 adopts an extended conformation with two pairs of heterodimerized domains. They contain longin domains that heterodimerize and contact both nucleotide binding domains of the Rag heterodimer, and C-terminal DENN domains which interact at the distal end of the structure [, , ].This is the N-terminal domain of folliculin, the longin domain [, , ]. An arginine residue located in this domain (Arg164) is catalytic residue for GAP activity [, ]. This domain can also be found in SMCR8, a component of the C9orf72-SMCR8 complex, a complex that has guanine nucleotide exchange factor (GEF) activity and regulates autophagy [, , , , , ]. |
