?
Rag GTPase, subfamily of Ras-related GTPases, includes Ras-related GTP-binding proteins A and B RagA and RagB are closely related Rag GTPases (ras-related GTP-binding protein A and B) that constitute a unique subgroup of the Ras superfamily, and are functional homologs of Saccharomyces cerevisiae Gtr1. These domains function by forming heterodimers with RagC or RagD, and similarly, Gtr1 dimerizes with Gtr2, through the carboxy-terminal segments. They play an essential role in regulating amino acid-induced target of rapamycin complex 1 (TORC1) kinase signaling, exocytic cargo sorting at endosomes, and epigenetic control of gene expression. In response to amino acids, the Rag GTPases guide the TORC1 complex to activate the platform containing Rheb proto-oncogene by driving the relocalization of mTORC1 from discrete locations in the cytoplasm to a late endosomal and/or lysosomal compartment that is Rheb-enriched and contains Rab-7.
|