Endosomal/lysosomal proton channel TMEM175 MSQPRTPEQA LDTPGDCPPG RRDEDAGEGI QCSQRMLSFS DALLSIIATV MILPVTHTEI SPEQFDRSVQ RLLATRIAVY LMTFLIVTVA WAAHTRLFQV VGKTDDTLAL LNL