New Isoform of Cardiac Myosin Light Chain Kinase and the Role of Cardiac Myosin Phosphorylation in α_{1 - Fig 3}-Adrenoceptor Mediated Inotropic Response

<p>(A) Phosphorylation levels of MLC2v determined by urea-glycerol-PAGE in C57BL/6J and C57BL/6N hearts. The ratio (%) of phosphorylated MLC2v <i>vs</i>. total MLC2v was calculated. The expression of smMLCK (B), ZIPK (C) and MYPT2 (myosin phosphatase target subunit 2) (D) in C57BL/6J and C57BL/6N hearts. Upper panels show representative Western blots and the lower panels summarize the densitometrical data. The expression level in C57BL/6J was expressed as 100%. *<i>P</i><0.05. <i>n</i> = 4.