Intracellular cholesterol transporter which acts in concert with NPC2 and plays an important role in the egress of cholesterol from the endosomal/lysosomal compartment (PubMed:
9211849, PubMed:
9927649, PubMed:
10821832, PubMed:
18772377, PubMed:
27238017, PubMed:
12554680). Unesterified cholesterol that has been released from LDLs in the lumen of the late endosomes/lysosomes is transferred by NPC2 to the cholesterol-binding pocket in the N-terminal domain of NPC1 (PubMed:
9211849, PubMed:
9927649, PubMed:
18772377, PubMed:
19563754, PubMed:
27238017, PubMed:
28784760). Cholesterol binds to NPC1 with the hydroxyl group buried in the binding pocket (PubMed:
19563754). Binds oxysterol with higher affinity than cholesterol. May play a role in vesicular trafficking in glia, a process that may be crucial for maintaining the structural and functional integrity of nerve terminals (Probable).