RRAGA, encoding Ras-related GTP-binding protein A (RagA), is a key regulator in the mechanistic target of rapamycin complex 1 (mTORC1) pathway. RagA initially senses cellular amino acids (e.g., leucine) and controls mTORC1's translocation to the lysosomal membrane. This pathway is crucial for regulating cell growth and metabolism in response to environmental cues, including nutrients [1,2,4]. Genetic models, such as gene knockout, are valuable for studying its functions.

In a study generating a RRAGA knockout human iPSC line, it was aimed to discover the biological roles of RagA, potentially helping develop new therapeutics for depression [1]. In another functional study, mutations of RRAGA associated with autosomal dominant cataracts disrupted mTORC1 signaling in human lens epithelial cells, with effects like increased RRAGA relocation to lysosomes, up-regulated mTORC1 phosphorylation, down-regulated autophagy, and altered cell growth [3].

In conclusion, RRAGA plays an essential role in the mTORC1 pathway by sensing amino acids and regulating mTORC1 translocation. Studies using gene knockout models have provided insights into its role in diseases such as depression and autosomal dominant cataracts, highlighting its potential as a therapeutic target for these conditions.