Nonselective cation channel probably playing a role in the regulation of membrane trafficking events. Acts as a Ca(2+)-permeable cation channel with inwardly rectifying activity (PubMed:19885840, PubMed:19940139). May activate ARF6 and be involved in the trafficking of GPI-anchored cargo proteins to the cell surface via the ARF6- regulated recycling pathway (PubMed:17662026). May play a role in immune processes. In adaptive immunity, TRPML2 and TRPML1 may play redundant roles in the function of the specialized lysosomes of B cells (By similarity). In the innate immune response, may play a role in the regulation of chemokine secretion and macrophage migration (By similarity). Through a possible and probably tissue-specific heteromerization with MCOLN1 may be at least in part involved in many lysosome-dependent cellular events (PubMed:19885840). Also functions as a Fe(2+) permeable channel (By similarity). {ECO:0000250|UniProtKB:Q8K595, ECO:0000269|PubMed:17662026, ECO:0000269|PubMed:19885840, ECO:0000269|PubMed:19940139, ECO:0000305}. This is the function of MCOLN2 (mucolipin TRP cation channel 2, Ensembl gene identifier ENSG00000153898).