Transmembrane 4 L6 family member 5

Acts as a lysosomal membrane arginine sensor. Forms a complex with MTOR and SLC38A9 on lysosomal membranes in an arginine-regulated manner, leading to arginine efflux which enables the activation of mTORC1 which subsequently leads to RPS6KB1 and EIF4EBP1 phosphorylations. Facilitates cell cycle G1/S phase progression and the translocation of the CDK4-CCND1 complex into the nucleus. CDKN1B and RHOA/ROCK signaling activity are involved in TM4SF5-mediated acceleration of G1/S phase progression.