KCNJ13

This gene encodes a member of the inwardly rectifying potassium channel family of proteins. Members of this family form ion channel pores that allow potassium ions to pass into a cell. The encoded protein belongs to a subfamily of low signal channel conductance proteins that have a low dependence on potassium concentration. Mutations in this gene are associated with snowflake vitreoretinal degeneration. Alternate splicing results in multiple transcript variants.[provided by RefSeq, Feb 2010]

Full Name

Potassium Voltage-Gated Channel Subfamily J Member 13

Function

Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. KCNJ13 has a very low single channel conductance, low sensitivity to block by external barium and cesium, and no dependence of its inward rectification properties on the internal blocking particle magnesium.

Biological Process

Potassium ion import across plasma membraneManual Assertion Based On ExperimentIBA:GO_Central
Potassium ion transport1 PublicationNAS:UniProtKB
Regulation of ion transmembrane transportManual Assertion Based On ExperimentIBA:GO_Central

Cellular Location

Membrane

Involvement in disease

Snowflake vitreoretinal degeneration (SVD):
Developmental and progressive hereditary eye disorder that affects multiple tissues within the eye. Diagnostic features of SVD include fibrillar degeneration of the vitreous humor, early-onset cataract, minute crystalline deposits in the neurosensory retina, and retinal detachment.
Leber congenital amaurosis 16 (LCA16):
A severe dystrophy of the retina, typically becoming evident in the first years of life. Visual function is usually poor and often accompanied by nystagmus, sluggish or near-absent pupillary responses, photophobia, high hyperopia and keratoconus.

Topology

Cytoplasmic: 1-53
Helical: 54-78
Extracellular: 79-105
Helical: 106-117
Pore-forming: 118-124
Extracellular: 125-133
Helical: 134-155
Cytoplasmic: 156-360

PTM

Phosphorylation at Ser-201 by PKC strongly inhibits ionic currents, while phosphorylation at Ser-287 by PKA increases them.