Selective expression of Kir6.1 protein in different vascular and non-vascular tissues.
K(ATP) channels are composed of pore-forming subunits Kir6.x and auxiliary subunits SURx. These channels play important roles in modulating the contractility of vascular smooth muscle cells (SMCs) by altering membrane potentials. The molecular basis of K(ATP) channels in vascular SMCs is unclear and the expression of different K(ATP) channel subunits at protein level in various tissues still undetermined. In this study, using an anti-Kir6.1 antibody, we detected the expression of Kir6.1 proteins in rat vascular tissues including mesenteric artery, pulmonary artery, aorta, and tail artery. Kir6.1 proteins were also identified in heart and other non-vascular tissues including spleen and brain, but they were undetectable in liver and kidney. Immunocytochemical study revealed the expression of Kir6.1 proteins in cultured rat thoracic aortic SMCs. Using the whole-cell patch-clamp technique, it was found that the intracellularly applied anti-Kir6.1 antibody significantly inhibited K(ATP) channel currents in HEK-293 cells that were stably transfected with Kir6.1 cDNA. A better understanding of differential expression of Kir6.1 proteins in various vascular and non-vascular tissues may help discern different molecular basis and functions of K(ATP) channel complexes in these tissues.
Sun
Xianfeng
X
Department of Physiology, College of Medicine, University of Saskatchewan, Sask., S7N 5E5, Saskatoon, Canada.
Cao
Kun
K
Yang
Guangdong
G
Huang
Yuan
Y
Hanna
Salma Toma
ST
Wang
Rui
R
D000818:Animals; D000906:Antibodies / Q000032:analysis; D019556:COS Cells; D002478:Cells, Cultured; D004594:Electrophysiology; D015870:Gene Expression; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D024661:Potassium Channels, Inwardly Rectifying / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism*; D014018:Tissue Distribution
D000906:Antibodies; D024661:Potassium Channels, Inwardly Rectifying