Ras-related GTP-binding protein B (RRAGB)

Guanine nucleotide-binding protein which plays a vital role in the cellular response to amino acid availability through regulation of the mTORC1 signaling cascade. Forms heterodimeric Rag complexes with RRAGC or RRAGD and cycles between an inactive GDP-bound and an energetic GTP-bound form.

In its active form participates in the relocalization of mTORC1 to the lysosomes and its subsequent activation by the GTPase RHEB. Involved from the RCC1/Ran-GTPase pathway.