tailieunhanh - Báo cáo khoa học: Nerve influence on myosin light chain phosphorylation in slow and fast skeletal muscles

Neural stimulation controls the contractile properties of skeletal muscle fibres through transcriptional regulation of a number of proteins, including myosin isoforms. To study whether neural stimulation is also involved in the control of post-translational modifications of myosin, we analysed the phosphorylation of alkali myosin light chains (MLC1) and regulatory myo-sin light chains (MLC2) in rat slow (soleus) and fast (extensor digitorum longus EDL) muscles using 2D-gel electrophoresis and mass spectrometry | ềFEBS Journal Nerve influence on myosin light chain phosphorylation in slow and fast skeletal muscles Cyril Bozzo1 2 Barbara Spolaore3 Luana Toniolo1 Laurence Stevens2 Bruno Bastide2 Caroline Cieniewski-Bernard2 Angelo Fontana3 Yvonne Mounier2 and Carlo Reggiani1 1 Department of Anatomy and Physiology University of Padova Italy 2 Laboratory of Neuromuscular Plasticity UPRES EA 1032 IFR118 USTL Villeneuve d Ascq France 3 CRIBI Biotechnology Centre University of Padova Italy Keywords CLFS cyclosporin denervation myosin phosphorylation Correspondence C. Reggiani Department of Anatomy and Physiology University of Padova Via Marzolo 3 35131 Padova Italy Fax 39 049827 5301 Tel 39 049827 5513 E-mail Received 23 May 2005 revised 2 August 2005 accepted 12 September 2005 doi Neural stimulation controls the contractile properties of skeletal muscle fibres through transcriptional regulation of a number of proteins including myosin isoforms. To study whether neural stimulation is also involved in the control of post-translational modifications of myosin we analysed the phosphorylation of alkali myosin light chains MLC1 and regulatory myosin light chains MLC2 in rat slow soleus and fast extensor digitorum longus EDL muscles using 2D-gel electrophoresis and mass spectrometry. In control rats soleus and EDL muscles differed in the proportion of the fast and slow isoforms of MLC1 and MLC2 that they contained and also in the distribution of the variants with distinct isoelectric points identified on 2D gels. Denervation induced a slow-to-fast transition in myosin isoforms and increased MLC2 phosphorylation in soleus whereas the opposite changes in myosin isoform expression and MLC2 phosphorylation were observed in EDL. Chronic low-frequency stimulation of EDL with a pattern mimicking that of soleus induced a fast-to-slow transition in myosin isoforms accompanied by a decreased MLC2 phosphorylation. Chronic administration 10 .