Localization of sulphonylurea receptor proteins SUR2A and SUR2B and/or SUR1 in rat kidney.

To further explore precise expression and localization of sulphonylurea receptor isoforms SUR2A and SUR2B (SUR1) in rat kidney, total RNA was isolated from the kidney tissue using the TRIzol kit. Three different primer sets designed against SUR isoforms were used in reverse transcriptase reactions. Western blotting was done on membrane fractions obtained from kidney tissues using the primary antisera for SUR2A and SUR2B (SUR1).

Functional and developmental expression of a zebrafish Kir1.1 (ROMK) potassium channel homologue Kcnj1.

The zebrafish, Danio rerio, is emerging as an important model organism for the pathophysiological study of some human kidney diseases, but the sites of expression and physiological roles of a number of protein orthologues in the zebrafish nephron remain mostly undefined. Here we show that a zebrafish potassium channel is orthologous to the mammalian kidney potassium channel, ROMK. The cDNA (kcnj1) encodes a protein (Kcnj1) that when expressed in Xenopus laevis oocytes displayed pH- and Ba2+-sensitive K+-selective currents, but unlike the mammalian channel, was completely insensitive to the peptide inhibitor tertiapin-Q.

Intraepithelial gammadelta+ lymphocytes maintain the integrity of intestinal epithelial tight junctions in response to infection.

Background & Aims: Intestinal epithelial integrity and permeability is dependent on intercellular tight junction (TJ) complexes. How TJ integrity is regulated remains unclear, although phosphorylation and dephosphorylation of the integral membrane protein occludin is an important determinant of TJ formation and epithelial permeability. We have investigated the role intestinal intraepithelial lymphocytes (iIELs) play in regulating epithelial permeability in response to infection.

The basolateral expression of mUT-A3 in the mouse kidney.

Facilitative UT-A urea transporters play a central role in the urinary concentrating mechanism. There are three major UT-A isoforms found in the mouse kidney: mUT-A1, mUT-A2, and mUT-A3. The major aim of this study was to identify the location and function of mUT-A3.

Evidence for endocytosis of ROMK potassium channel via clathrin-coated vesicles.

ROMK channels are present in the cortical collecting ducts of kidney and are responsible for K(+) secretion in this nephron segment. Recent studies suggest that endocytosis of ROMK channels is important for regulation of K(+) secretion in cortical collecting ducts. We investigated the molecular mechanisms for endocytosis of ROMK channels expressed in Xenopus laevis oocytes and cultured Madin-Darby canine kidney cells.