TMEM175 Antibody - #DF12777

Organelle-specific potassium channel specifically responsible for potassium conductance in endosomes and lysosomes. Forms a potassium-permeable leak-like channel, which regulates lumenal pH stability and is required for autophagosome-lysosome fusion. Constitutes the major lysosomal potassium channel.

Endosome membrane>Multi-pass membrane protein. Lysosome membrane>Multi-pass membrane protein.

Widely expressed.

Composed of two modules of six transmembranes, forming a homodimer with a tetrameric architecture (PubMed:28723891). The six transmembrane regions of each module are tightly packed within each subunit without undergoing domain swapping (By similarity). Transmembranes TM1-TM3 of each module are positioned on the inner circle of the channel tetramer and participate in inter-subunit interactions that are central to the assembly of the ion conduction pore (By similarity). The RxxxFSD motifs within transmembranes TM1 coordinate a network of specific inter- and intra-subunit interactions with other conserved residues on TM2 and TM3 and play a key role in the tetrameric assembly of the channel (By similarity). Transmembranes TM4-TM6 are positioned on the periphery of the channel and do not contribute contacts with neighboring subunits (By similarity). Transmembranes TM1 and TM2 are linked by an extended strand-like tail and two short helices (H1 and H2) which protrude outwards from the main body of the transmembrane domain and enclose the external open entrance of the ion conduction pore in the channel tetramer (By similarity). Transmembranes TM1 form the pore-lining inner helix at the center of the channel, creating an hourglass-shaped ion permeation pathway in the channel tetramer (By similarity). Three hydrophobic residues on the C-terminal half of the TM1 helices form a bottleneck along the ion conduction pathway and serve as the selectivity filter of the channel (By similarity). Ile-46 (and Ile-271) are probably responsible for channel selectivity (PubMed:28723891).

Belongs to the TMEM175 family.