Guanine nucleotide-binding protein that plays a crucial role in the cellular response to amino acid availability through regulation of the mTORC1 signaling cascade (PubMed:20381137, PubMed:24095279, PubMed:25936802). Forms heterodimeric Rag complexes with RRAGC or RRAGD and cycles between an inactive GDP-bound and an active GTP-bound form (PubMed:20381137, PubMed:24095279, PubMed:25936802). In its active form participates in the relocalization of mTORC1 to the lysosomes and its subsequent activation by the GTPase RHEB (PubMed:20381137, PubMed:25936802). Involved in the RCC1/Ran-GTPase pathway (PubMed:9394008). May play a direct role in a TNF-alpha signaling pathway leading to induction of cell death (PubMed:8995684). (Microbial infection) May alternatively act as a cellular target for adenovirus E3-14.7K, an inhibitor of TNF-alpha functions, thereby affecting cell death. GTP + H2O = GDP + H(+) + phosphate The activation of GTP-binding proteins is generally mediated by a guanine exchange factor (GEF), while inactivation through hydrolysis of bound GTP is catalyzed by a GTPase activating protein (GAP) (PubMed:25936802). The GATOR1 complex functions as a GAP and stimulates RRAGA GTPase activity to turn it into its inactive GDP-bound form (PubMed:25936802, PubMed:23723238). Can occur as a homodimer or as a heterodimer with RRAGC or RRAGD in a sequence-independent manner; heterodimerization stabilizes proteins of the heterodimer (PubMed:11073942, PubMed:20381137). In complex with RRAGC, but not with RRAGB, interacts with RPTOR (PubMed:18497260). The GTP-bound form of RRAGA interacts with NOL8 (PubMed:14660641). Component of the lysosomal folliculin complex (LFC), composed of FLCN, FNIP1 (or FNIP2), RRAGA/RagA or RRAGB/RagB GDP-bound, RRAGC/RagC or RRAGD/RagD GTP-bound, and Ragulator (PubMed:31704029, PubMed:31672913). Interacts with SH3BP4; the interaction with this negative regulator is most probably direct, preferentially occurs with the inactive GDP-bound form of RRAGA and is negatively regulated by amino acids (PubMed:22575674). The Rag heterodimer interacts with SLC38A9; the probable amino acid sensor (PubMed:25561175, PubMed:25567906). Interacts (inactive GDP-bound form) with RNF152; stimulated by amino acid starvation (PubMed:25936802). Interacts (polyubiquitinated) with the GATOR1 complex; inactivates RRAGA (PubMed:25936802). Interacts (polyubiquitinated) with TSC2 (PubMed:25936802). Interacts with SESN1, SESN2 and SESN3 (PubMed:25259925). Interacts with PIP4P1 (By similarity). Interacts with GPR137B (PubMed:31036939). (Microbial infection) Interacts with adenovirus E3 14.7 kDa protein. Predominantly cytoplasmic. May shuttle between the cytoplasm and nucleus, depending on the bound nucleotide state (PubMed:8995684, PubMed:9394008). Colocalizes in vivo with adenovirus E3-14.7K mainly to the cytoplasm especially near the nuclear membrane and in discrete foci on or near the plasma membrane (PubMed:8995684). Ubiquitously expressed with highest levels of expression in skeletal muscle, heart, and brain. Ubiquitinated. 'Lys-68'-linked polyubiquitination of the GDP-bound inactive form of RRAGA by RNF152 is increased in response to amino acid starvation. Polyubiquitination promotes interaction with the GATOR1 complex. This does not affect RRAGA degradation. Belongs to the GTR/RAG GTP-binding protein family.