May play a role in cholesterol transfer to late endosomes (PubMed:19696025). May play a role in modulating membrane acid-sensing ion channels. Can specifically inhibit proton-gated current of ASIC1 isoform 1. Can increase inactivation speed of ASIC3. May be involved in regulation of proton sensing in dorsal root ganglions (By similarity). May play a role in protecting FBXW7 isoform 3 from degradation (PubMed:23082202). Interacts with STOM; may redistribute STOM from the plasma membrane to late endosomes (PubMed:19696025). Interacts with FBXW7 isoform 3 and CDK2 (PubMed:23082202). Ubiquitously expressed at low levels. Expression is highest in brain. Belongs to the band 7/mec-2 family.