RHEBL1

RhebL1 is a small GTPase of the Ras superfamily, encoded by the RHEBL1 gene in humans. It is closely related to Rheb1 and shares sequence features including the GTPase domain and a C-terminal lipid modification motif that targets the protein to cellular membranes. RhebL1 operates as a molecular switch, cycling between GTP-bound active and GDP-bound inactive forms.

Like other Rheb family members, RhebL1 is thought to localize to lysosomal and other endomembrane compartments, and its activity is governed by guanine nucleotide exchange factors and GTPase-activating proteins. The precise regulatory inputs and effectors of RhebL1 are less well defined than those of Rheb1.

Functionally, RhebL1 is implicated in the regulation of anabolic growth pathways, particularly the mTOR signaling axis, which controls protein synthesis, cell growth, and metabolism. However, its contribution relative to Rheb1 appears to be context-dependent, varying by tissue or species, and remains an active area of study.

Clinical relevance is not yet established; research is ongoing to determine whether RHEBL1 has roles in human diseases such as cancer or metabolic disorders.

Discovery and nomenclature: The protein is widely referred to as RHEBL1 (Rheb-like 1). It is one of the small GTPases in the Rheb family and shares evolutionary and functional features with Rheb1.