title: Regulation of ion channels by secreted Klotho.
abstract: Klotho is an anti-aging protein predominantly expressed in the kidney, parathyroid glands and choroid plexus of the brain. Klotho exists in two forms, a membrane form and a soluble secreted form. Recent studies show that the secreted Klotho possess sialidase activity and regulates several ion channels via the activity. Removal of terminal sialic acids from N-glycan chains of the epithelial Ca(2+) channel TRPV5 and the renal K(+) channel ROMK by secreted Klotho exposes the underlying disaccharide galactose-N-acetylglucosamine, a ligand for galectin-1. Binding to galectin-1 at the extracellular surface prevents internalization and leads to accumulation of the channels on the plasma membrane. Future studies will investigate whether secreted Klotho regulates cell-surface expression of other membrane glycoproteins via the same mechanism.
authors.affiliation: Department of Medicine, UT Southwestern Medical Center, Dallas, TX, USA. Chou-Long.Huang@utsouthwestern.edu
authors.forename: Chou-Long
authors.initials: CL
authors.lastname: Huang
mesh_terms: D000375:Aging / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D005966:Glucuronidase / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D000090265:Klotho Proteins; D017386:Sequence Homology, Amino Acid
chemical_list: D007473:Ion Channels; D005966:Glucuronidase; D000090265:Klotho Proteins