title: The alpha(1G)-subunit of a voltage-dependent Ca(2+) channel is localized in rat distal nephron and collecting duct.
abstract: The molecular type and localization of calcium channels along the nephron are not well understood. In the present study, we assessed the distribution of the recently identified alpha(1G)-subunit encoding a voltage-dependent calcium channel with T-type characteristics. Using a RNase protection assay, alpha(1G)-mRNA levels in kidney regions were determined as inner medulla >> outer medulla congruent with cortex. RT-PCR analysis of microdissected rat nephron segments revealed alpha(1G) expression in the distal convoluted tubule (DCT), in the connecting tubule and cortical collecting duct (CT+CCD), and inner medullary collecting duct (IMCD). alpha(1G) mRNA was expressed in the IMCD cell line mIMCD-3. Single- and double-labeling immunohistochemistry and confocal laser microscopy on semithin paraffin sections of rat kidneys by using an anti-alpha(1G) antibody demonstrated a distinct labeling at the apical plasma membrane domains of DCT cells, CT principal cells, and IMCD principal cells.
authors.affiliation: Department of Physiology and Pharmacology, University of Southern Denmark-Odense University, DK-5000 Odense, Denmark.
authors.forename: D
authors.initials: D
authors.lastname: Andreasen
authors.forename: B L
authors.initials: BL
authors.lastname: Jensen
authors.forename: P B
authors.initials: PB
authors.lastname: Hansen
authors.forename: T H
authors.initials: TH
authors.lastname: Kwon
authors.forename: S
authors.initials: S
authors.lastname: Nielsen
authors.forename: O
authors.initials: O
authors.lastname: Skøtt
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D020747:Calcium Channels, T-Type / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D003001:Cloning, Molecular; D007124:Immunoenzyme Techniques; D007685:Kidney Tubules, Collecting / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D018613:Microscopy, Confocal; D009399:Nephrons / Q000378:metabolism* / Q000648:ultrastructure; D023282:Nuclease Protection Assays; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014018:Tissue Distribution
chemical_list: C500994:Cacna1g protein, rat; D020747:Calcium Channels, T-Type; D012333:RNA, Messenger