Inwardly rectifying potassium channel 5.1: Structure, function, and possible roles in diseases.

Inwardly rectifying potassium (Kir) channels make it easier for K to enter into a cell and subsequently regulate cellular biological functions. Kir5.1 (encoded by ) alone can form a homotetramer and can form heterotetramers with Kir4.1 (encoded by ) or Kir4.2 (encoded by ). In most cases, homomeric Kir5.1 is non-functional, while heteromeric Kir5.1 on the cell membrane contributes to the inward flow of K ions, which can be regulated by intracellular pH and a variety of signaling mechanisms. In the form of a heterotetramer, Kir5.1 regulates Kir4.1/4.2 activity and is involved in the maintenance of nephron function. Actually, homomeric Kir5.1 may also play a very important role in diseases, including in the ventilatory response to hypoxia and hypercapnia, hearing impairment, cardiovascular disease and cancer. With an increase in the number of studies into the roles of Kir channels, researchers are paying more attention to the pathophysiological functions of Kir5.1. This minireview provides an overview regarding these Kir5.1 roles.