Fenyvesi Rita, Rácz Gábor, Wuytack Frank, Zádor Erno
Institute of Biochemistry, Faculty of Medicine, University of Szeged, P.O. Box 427, H-6701 Szeged, Hungary.
Biochem Biophys Res Commun. 2004 Jul 23;320(2):599-605. doi: 10.1016/j.bbrc.2004.06.005.
The level of active subunit of calcineurin and the calcineurin (Cn) enzyme activity are increased in innervated but not in denervated slow type regenerating skeletal soleus muscle. These nerve-dependent increases were not accompanied by similar increases in the mRNA levels. The changes in the mRNA level of the modulatory calcineurin interacting protein, MCIP1.4, reflected the calcineurin activity and did not increase in denervated regenerating muscles compared to the innervated regenerating controls. The increases in Cn activity and in MCIP1.4 mRNA levels occurred before the switch from fast to slow-type myosin heavy chain isoforms, a phenomenon similarly known to be dependent on innervation. This highlights the role of mediators, acting between the nerve and calcineurin, in the formation of slow fiber identity.
在受神经支配的慢肌型再生比目鱼肌中，钙调神经磷酸酶活性亚基水平和钙调神经磷酸酶（Cn）酶活性升高，但在去神经支配的慢肌型再生比目鱼肌中未升高。这些依赖神经的升高并未伴随着mRNA水平的类似升高。调节性钙调神经磷酸酶相互作用蛋白MCIP1.4的mRNA水平变化反映了钙调神经磷酸酶活性，与受神经支配的再生对照相比，去神经支配的再生肌肉中该水平并未升高。Cn活性和MCIP1.4 mRNA水平的升高发生在从快肌型肌球蛋白重链异构体向慢肌型肌球蛋白重链异构体转变之前，这一现象同样已知依赖于神经支配。这突出了在神经与钙调神经磷酸酶之间起作用的介质在慢肌纤维特性形成中的作用。
