Isoforms of the Na-K-2Cl cotransporter in murine TAL I. Molecular characterization and intrarenal localization.

We have identified several alternatively spliced cDNAs encoding mBSC1, an apical bumetanide-sensitive Na+-K+-2Cl- cotransporter from mouse kidney. Two full-length clones were isolated, designated C4 and C9, predicting proteins of 770 and 1,095 amino acids, respectively. The C4 isoforms are generated by utilization of an alternative polyadenylation site located within the intron between exons 16 and 17 of the mBSC1 gene on chromosome 2; the resultant transcripts predict a truncated COOH terminus ending in a unique 55 amino acid sequence.

Novel protein kinase C, nPKC, inhibition of murine bumetanide-sensitive Na+,K+,2Cl- cotransporter BSC1 in Xenopus oocyte.

In vitro transcribed RNAs obtained for the absorptive type of Na,K, 2Cl cotransporter BSC1, isoform F, and either of three deletion mutants were injected into oocytes, while oocytes injected with water served as controls. Wild-type cRNA induced a bumetanide-sensitive Rb flux after 18 h which rose to a maximum of about 600 pmol . (h.

Antibodies against a furosemide binding protein from Ehrlich ascites tumour cells inhibit Na+, K+, Cl- co-transport in frog retinal pigment epithelium.

Purpose: To investigate whether antibodies against a 100 kDa protein purified by furosemide affinity chromatography from Ehrlich ascites tumour cells could inhibit Na+, K+, Cl- co-transport in the isolated frog retinal pigment epithelium.

Methods: The rate of Na+, K+, Cl- co-transport across the retinal membrane in the isolated frog RPE preparation was measured as the rate of decrease in the intracellular Cl- activity observed after administration of furosemide in the apical bath. The intracellular Cl- activity was measured with double barrelled Cl- sensitive microelectrodes.

Multiple sequence elements in the U3 region of the leukemogenic murine retrovirus SL3-2 contribute to cell-dependent gene expression.

Determination of the U3 sequence of the leukemogenic murine retrovirus SL3-2 revealed close relationships to SL3-3, Akv, and Gross passage A viruses. The SL3-2 and Akv regions showed wide differences in their relative transcriptional activity in four cell lines as determined by U3-driven transient expression assays. The U3 regions of SL3-2 and SL3-3 gave rise to similar but not identical levels of expression.