Kcnj15 Knockout mouse models

Kcnj15, the mouse ortholog of human KCNJ15, encodes Kir4.2, an inwardly rectifying potassium channel closely related to Kir4.1 that assembles as a homotetramer or, more commonly in native tissue, as a heteromer with Kir5.1 encoded by Kcnj16, an arrangement that confers steep sensitivity to intracellular pH and carbon dioxide. Kir4.2 is expressed on the basolateral membrane of proximal tubule and other kidney segments, in liver, pancreas, and lung, and in restricted neural populations, where it contributes to potassium recycling that supports electrogenic transport and to acid-base sensing. The gene lies within the Down syndrome critical region on human chromosome 21 and has been linked to glucose handling and diabetic nephropathy risk. Conditional nulls with segment-restricted Cre drivers are the appropriate design for transport phenotypes, while pH-sensing residue knockins test the chemosensory hypothesis directly. Because Kir4.1 covers overlapping territory in some tissues, quantify heteromer composition rather than assuming a clean single-subunit loss.

Kcnj15 null animals are straightforward to genotype and phenotype when survival is acceptable. They remain a standard background for pharmacology, biomarker, and rescue studies.