Muscle LIM protein: expressed in slow muscle and induced in fast muscle by enhanced contractile activity.
Muscle LIM protein: expressed in slow muscle and induced in fast muscle by enhanced contractile activity.
复制标题
DOI：
10.1152/ajpcell.1999.276.4.c900
复制
发表时间：
1999-04
期刊：
影响因子：
--
通讯作者：
A. G. Schneider;Karim R. Sultan;Dirk Pette
中科院分区：
文献类型：
--
作者：
A. G. Schneider;Karim R. Sultan;Dirk Pette
为了确定在慢性低频刺激诱导的快到慢的转变过程中基因表达的早期变化，从12小时刺激的大鼠胫骨前肌（TA）中提取总RNA，并通过差异显示RT-PCR扩增。在差异表达的mRNAs信号中，鉴定了长度为约300 bp的cDNA，其在对照TA肌肉中几乎检测不到，但在刺激的TA和正常比目鱼肌中突出。该cDNA被克隆并鉴定为对应于肌肉LIM蛋白（MLP）的mRNA。通过北方印迹法验证了其在对照、刺激的TA和比目鱼肌中的差异表达。使用抗MLP的抗体通过免疫印迹分析鉴定MLP的预测分子量22 kDa的蛋白质。免疫组化显示，MLP在正常比目鱼肌的所有纤维和一些IIA型和I型纤维在控制TA肌微弱的染色强反应。这些纤维的数量和染色强度增加，在4天的刺激TA肌肉。因此，MLP似乎在转化成人肌纤维的细胞骨架和/或肌原纤维结构的重排过程中发挥重要作用。
To identify early changes in gene expression during the fast-to-slow transition induced by chronic low-frequency stimulation, total RNA was extracted from 12-h-stimulated tibialis anterior (TA) muscles of rats and amplified by differential display RT-PCR. Among the signals of differentially expressed mRNAs, a cDNA ∼300 bp in length, which was almost undetectable in control TA muscles but prominent in stimulated TA and normal soleus muscles, was identified. This cDNA was cloned and identified as corresponding to the mRNA of the muscle LIM protein (MLP). Its differential expression in control, stimulated TA, and soleus muscles was verified by Northern blotting. Antibodies against MLP were used to identify by immunoblot analysis a protein of 22 kDa, the predicted molecular mass of MLP. Immunohistochemistry revealed strong reactivity for MLP in all fibers of normal soleus muscle and faint staining of some type IIA and type I fibers in control TA muscle. These fibers increased in number and staining intensity in 4-day-stimulated TA muscle. MLP thus seems to play an essential role during the rearrangement of cytoskeletal and/or myofibrillar structures in transforming adult muscle fibers.