Mucolipin-1 (ML1) also known as TRPML1 (transient receptor potential cation channel, mucolipin subfamily, member 1) is a protein that in humans is encoded by the MCOLN1 gene. It is a member of the small family of the TRPML channels, a subgroup of the large protein family of TRP ion channels. TRPML1 is a 65 kDa protein associated with mucolipidosis type IV. Its predicted structure includes six transmembrane domains, a transient receptor potential (TRP) cation-channel domain, and an internal channel pore. TRPML1 is believed to channel iron ions across the endosome/lysosome membrane into the cell and so its malfunction causes cellular iron deficiency. It is important in lysosome function and plays a part in processes such as vesicular trafficking, exocytosis and autophagy.