Normal vision and development in mice with low functional expression of Kir7.1 in heterozygosis for a blindness-producing mutation inactivating the channel.

K channel Kir7.1 expressed at the apical membrane of the retinal pigment epithelium (RPE) plays an essential role in retinal function. An isoleucine-to-threonine mutation at position 120 of the protein is responsible for blindness-causing vitreo-retinal dystrophy.

Kir7.1 inwardly rectifying K channel is expressed in ciliary body non pigment epithelial cells and might contribute to intraocular pressure regulation.

Inwardly rectifying K channel Kir7.1 is expressed in epithelia where it shares membrane localisation with the Na/K-pump. The ciliary body epithelium (CBE) of the eye is a determinant of intraocular pressure (IOP) through NaCl-driven fluid secretion of aqueous humour.

A novel Kir7.1 splice variant expressed in various mouse tissues shares organisational and functional properties with human Leber amaurosis-causing mutations of this K channel.

Kir7.1 is an inwardly rectifying K channel present in epithelia where it shares membrane localization with the Na/K-pump. In the present communication we report the presence of a novel splice variant of Kir7.

Tissue Distribution of Kir7.1 Inwardly Rectifying K Channel Probed in a Knock-in Mouse Expressing a Haemagglutinin-Tagged Protein.

Kir7.1 encoded by the gene in the mouse is an inwardly rectifying K channel present in epithelia where it shares membrane localization with the Na/K-pump. Further investigations of the localisation and function of Kir7.

K TASK-2 and KCNQ1-KCNE3 K channels are major players contributing to intestinal anion and fluid secretion.

Key Points: K channels are important in intestinal epithelium as they ensure the ionic homeostasis and electrical potential of epithelial cells during anion and fluid secretion. Intestinal epithelium cAMP-activated anion secretion depends on the activity of the (also cAMP dependent) KCNQ1-KCNE3 K channel, but the secretory process survives after genetic inactivation of the K channel in the mouse. Here we use double mutant mice to investigate which alternative K channels come into action to compensate for the absence of KCNQ1-KCNE3 K channels.

Cleft Palate, Moderate Lung Developmental Retardation and Early Postnatal Lethality in Mice Deficient in the Kir7.1 Inwardly Rectifying K+ Channel.

Kir7.1 is an inwardly rectifying K+ channel of the Kir superfamily encoded by the kcnj13 gene. Kir7.

Novel CLCNKB mutations causing Bartter syndrome affect channel surface expression.

Mutations in the CLCNKB gene encoding the ClC-Kb Cl(-) channel cause Bartter syndrome, which is a salt-losing renal tubulopathy. Here, we investigate the functional consequences of seven mutations. When expressed in Xenopus laevis oocytes, four mutants carried no current (c.

ClC-5 mutations associated with Dent's disease: a major role of the dimer interface.

Dent's disease is an X-linked recessive disorder affecting the proximal tubules. Mutations in the 2Cl(-)/H(+) exchanger ClC-5 gene CLCN5 are frequently associated with Dent's disease. Functional characterization of mutations of CLCN5 have helped to elucidate the physiopathology of Dent's disease and provided evidence that several different mechanisms underlie the ClC-5 dysfunction in Dent's disease.

Extracellular pH in restricted domains as a gating signal for ion channels involved in transepithelial transport.

The importance of intracellular pH (pH(i)) in the regulation of diverse cellular activities ranging from cell proliferation and differentiation to cell cycle, migration and apoptosis has long been recognised. More recently, extracellular pH (pH₀), in particular that of relatively inaccessible compartments or domains that occur between cells in tissues, has begun to be acknowledged as a relevant signal in cell regulation. This should not be surprising given the abundant reports highlighting the pH₀-dependence of the activity of membrane proteins facing the extracellular space such as receptors, transporters, ion channels and enzymes.