{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\n LAMTOR1, also known as p18, is a critical lysosomal adaptor protein that functions as a scaffold within the Ragulator complex. By “wrapping” around the other Ragulator components, LAMTOR1 stabilizes the assembly on the lysosomal membrane and is essential for recruiting the Rag GTPases into a conformation that permits efficient mTORC1 activation in response to amino acid availability."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "1", "end_ref": "3"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n In addition to activating mTORC1 signaling, LAMTOR1 plays an important role in lysosomal homeostasis. Its function is linked not only to proper lysosomal positioning and maturation—ensuring the late endosome–lysosome fusion necessary for normal protein degradation and autophagic flux—but also to the overall integration of nutrient sensing with cellular metabolic control."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "4"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n The importance of LAMTOR1 is further underscored in pathological contexts. For instance, oncogenic gene fusions that combine the membrane-binding domain of LAMTOR1 with the catalytic domain of protein kinase C isoforms have been identified in benign fibrous histiocytomas, suggesting that aberrant LAMTOR1 activity can drive dysregulated kinase signaling and contribute to tumorigenesis."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "6"}]}, {"type": "t", "text": " Moreover, post-translational modifications such as N‑myristoylation stabilize LAMTOR1 and enhance its lysosomal localization, a modification that has been implicated in the progression of cancers like bladder cancer."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "7"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n In addition, interactions between LAMTOR1 and other proteins involved in lysosomal acidification and signaling (for example, components of the v‑ATPase complex and the tumor suppressor TMEM127) highlight its role as a finely tuned regulator of mTORC1 activity and lysosomal function. Defects in these interactions can lead to aberrant mTORC1 signaling and contribute to disease states."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "8"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n Overall, LAMTOR1 acts as an essential nexus between amino acid sensing, lysosomal dynamics, and mTORC1 activation. Its proper function is fundamental for maintaining cellular metabolic homeostasis, and its dysregulation is associated with diverse pathological outcomes, including aberrant cell growth and cancer.\n "}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Yasemin Sancak, Liron Bar-Peled, Roberto Zoncu, et al. 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