Cation channel activity of mucolipin-1: the effect of calcium.

Mucolipidosis type IV (MLIV) is a rare, neurogenetic disorder characterized by developmental abnormalities of the brain, and impaired neurological, ophthalmological, and gastric function. Considered a lysosomal disease, MLIV is characterized by the accumulation of large vacuoles in various cell types. Recent evidence indicates that MLIV is caused by mutations in MCOLN1, the gene that encodes mucolipin-1 (ML1), a 65-kDa protein showing sequence homology and topological similarities with polycystin-2 and other transient receptor potential (TRP) channels.

Cytoskeletal regulation of calcium-permeable cation channels in the human syncytiotrophoblast: role of gelsolin.

The human syncytiotrophoblast (hST) is the most apical epithelial barrier that covers the villous tree of the human placenta. An intricate and highly organized network of cytoskeletal structures supports the hST. Recently, polycystin-2 (PC2), a TRP-type nonselective cation channel, was functionally observed in hST, where it may be an important player to Ca2+ transport.

Molecular pathophysiology of mucolipidosis type IV: pH dysregulation of the mucolipin-1 cation channel.

Mucolipidosis type IV (MLIV) is an autosomal recessive neurogenetic disorder characterized by developmental abnormalities of the brain and impaired neurological, ophthalmologic and gastric function. Large vacuoles accumulate in various types of cells in MLIV patients. However, the pathophysiology of the disease at the cellular level is still unknown.

Polycystin-1 activates and stabilizes the polycystin-2 channel.

Autosomal dominant polycystic kidney disease (ADPKD) is a prevalent genetic disorder largely caused by mutations in the PKD1 and PKD2 genes that encode the transmembrane proteins polycystin-1 and -2, respectively. Both proteins appear to be involved in the regulation of cell growth and maturation, but the precise mechanisms are not yet well defined. Polycystin-2 has recently been shown to function as a Ca(2+)-permeable, non-selective cation channel.