Rab7iga

Rab7iga is a small GTPase proposed to belong to the Rab family of membrane trafficking regulators. The name reflects its putative interaction with Rab7 and its involvement in late endosome and lysosome pathways. In the current literature, Rab7iga has been described in a limited number of studies and is not yet widely characterized.

Molecularly, Rab7iga is predicted to adopt the conserved Rab fold, featuring a GTP-binding domain and switch regions that control its active state. Like other Rab proteins, it is anchored to membranes by a C-terminal prenylation motif, which targets it to late endosomal membranes where it exerts its function. The estimated size is in the 20–25 kDa range.

Functionally, Rab7iga is proposed to cycle between GDP- and GTP-bound forms, with the GTP-bound form promoting recruitment of effector proteins to late endosomes and facilitating maturation and fusion with lysosomes. It is thought to cooperate with Rab7 to regulate cargo sorting and autophagic flux, and to participate in endosome-lysosome tethering and SNARE-mediated fusion.

Regulation and interactions are hypothesized to involve dedicated GEFs that accelerate nucleotide exchange and GAPs that stimulate hydrolysis, as well as interactions with Rab7 and components of tethering complexes such as HOPS. Post-translational modifications could modulate its membrane association and activity.

Research on Rab7iga remains exploratory. In cell models, perturbation of Rab7iga activity has been reported to influence endosomal morphology and trafficking efficiency, but results require replication and refinement. The protein is primarily of interest to basic cell biology and may offer insights into endolysosomal regulation or disease models; clinical relevance has not been established.