Kir2x

Kir2x refers to a family of inwardly rectifying potassium channels, also known as KCNJ genes. These channels play a crucial role in regulating the resting membrane potential of various cell types, including neurons, cardiomyocytes, and epithelial cells. The "2x" designation indicates that these channels form functional homomers or heteromers composed of subunits from the Kir2 subfamily.

The Kir2 family comprises several members, such as Kir2.1, Kir2.2, Kir2.3, and Kir2.4. These subunits assemble into tetrameric channels, where each subunit contributes to the pore and gating mechanisms. Inward rectification is a hallmark of these channels, meaning they conduct potassium ions more readily when the membrane potential is negative relative to the potassium equilibrium potential. This property helps stabilize the resting membrane potential and influences cellular excitability.

Dysfunction of Kir2x channels has been implicated in a range of diseases. For instance, mutations in KCNJ genes encoding Kir2x subunits have been linked to cardiac arrhythmias, such as Romano-Ward and Jervell and Lange-Nielsen syndromes, which are characterized by long QT intervals. In the nervous system, alterations in Kir2x channel function can affect neuronal excitability and contribute to neurological disorders. Research continues to explore the precise roles and therapeutic potential of modulating Kir2x channel activity.