Ragulator complex protein LAMTOR4 (Lamtor4)

As part of the Ragulator complex it is involved in amino acid sensing and activation of mTORC1, a signaling complex promoting cell growth in response to growth factors, energy levels, and amino acids. Activated by amino acids via a mechanism involving the lysosomal V-ATPase, the Ragulator acts as a guanine nucleotide exchange factor activating the little GTPases Rag.

Activated Ragulator and Rag GTPases function as a scaffold recruiting mTORC1 to lysosomes where it is subsequently activated (By similarity). .