Concordant expression of KChIP2 mRNA, protein and transient outward current throughout the canine ventricle

Citations Over TimeTop 10% of 2003 papers

Abstract

Expression of the transient outward K+ current (Ito) was analysed in nine different regions of the canine ventricle. In addition to the previously described transmural gradients in the right and left ventricular free walls, an inverted U-shaped pattern of Ito expression was observed in the interventricular septum. The mRNA and protein expression for the K+ channel beta subunit KChIP2 were examined in the same tissues. The KChIP2 protein levels closely matched mRNA expression in all regions of the ventricle and paralleled the density of Ito. The global pattern of gene expression in human epicardial and endocardial tissue was examined using microarrays. Only 0.1 % of the genes expressed in the human ventricle displayed the same expression pattern as the KChIP2 gene in left ventricle. It is unlikely, therefore, that the reported distribution of KChIP2 protein within the ventricle can be explained by a cross-reaction of the anti-KChIP2 antibody with a different protein. It is concluded that transcriptional regulation of the KChIP2 gene is a primary determinant of Ito expression in heart.

Related Papers

• → Modulation of A-type potassium channels by a family of calcium sensors(2000)969 cited
• → Role of the Kv4.3 K+Channel in Ventricular Muscle(1996)435 cited
• → A Defect in the Kv Channel-Interacting Protein 2 (KChIP2) Gene Leads to a Complete Loss of Ito and Confers Susceptibility to Ventricular Tachycardia(2001)412 cited
• → Regulation of KChIP2 potassium channel β subunit gene expression underlies the gradient of transient outward current in canine and human ventricle(2001)281 cited
• → Role of Heteromultimers in the Generation of Myocardial Transient Outward K + Currents(2002)155 cited