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Updated: Aug 12, 2025

Recording of Inward Rectifying K+ Currents in Freshly Isolated Basilar Artery Smooth Muscle Cells by Patch Clamp Technique
Published on: February 7, 2025
The unique structural characteristics of the Kir 7.1 inward rectifier potassium channel: a novel player in energy
Ciria C Hernandez1, Luis E Gimenez1, Naima S Dahir1
1Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States.
Abstract:
The inward rectifier potassium channel Kir7.1, encoded by the KCNJ13 gene, is a tetramer composed of two-transmembrane domain-spanning monomers, closer in homology to Kir channels associated with potassium transport such as Kir1.1, 1.2, and 1.3. Compared with other channels, Kir7.1 exhibits small unitary conductance and low dependence on external potassium. Kir7.1 channels also show a phosphatidylinositol 4,5-bisphosphate (PIP2) dependence for opening. Accordingly, retinopathy-associated Kir7.1 mutations mapped at the binding site for PIP2 resulted in channel gating defects leading to channelopathies such as snowflake vitreoretinal degeneration and Leber congenital amaurosis in blind patients. Lately, this channel's role in energy homeostasis was reported due to the direct interaction with the melanocortin type 4 receptor (MC4R) in the hypothalamus. As this channel seems to play a multipronged role in potassium homeostasis and neuronal excitability, we will discuss what is predicted from a structural viewpoint and its possible implications for hunger control.
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