Sielski Neil L, Ihnatovych Ivanna, Hagen Jacob J, Hofmann Wilma A
Department of Physiology and Biophysics, University at Buffalo-State University of New York, 3435 Main Street, Buffalo, NY 14214, USA.
BMC Cell Biol. 2014 Mar 11;15:8. doi: 10.1186/1471-2121-15-8.
Myosin IC is a single headed member of the myosin superfamily that localizes to the cytoplasm and the nucleus and is implicated in a variety of processes in both compartments. We recently identified a novel isoform of myosin IC and showed that the MYOIC gene in mammalian cells encodes three isoforms (isoforms A, B, and C) that differ only in the addition of short isoform-specific N-terminal peptides. The expression pattern of the isoforms and the mechanisms of expression regulation remain unknown.
To determine the expression patterns of myosin IC isoforms, we performed a comprehensive expression analysis of the two myosin IC isoforms (isoform A and B) that contain isoform-specific sequences. By immunoblotting with isoform-specific antibodies and by qRT-PCR with isoform-specific primer we demonstrate that myosin IC isoforms A and B have distinct expression patterns in mouse tissues. Specifically, we show that myosin IC isoform A is expressed in a tissue specific pattern, while myosin IC isoform B is ubiquitously expressed at comparable levels in mouse tissues.
The differences in the expression profile of the myosin IC isoforms indicate a tissue-specific MYOIC gene regulation and further suggest that the myosin IC isoforms, despite their high sequence homology, might have tissue-specific and isoform-specific functions.
肌球蛋白IC是肌球蛋白超家族的单头成员，定位于细胞质和细胞核，参与这两个区室中的多种过程。我们最近鉴定出一种新型的肌球蛋白IC同工型，并表明哺乳动物细胞中的MYOIC基因编码三种同工型（同工型A、B和C），它们仅在添加短的同工型特异性N端肽方面有所不同。这些同工型的表达模式和表达调控机制仍然未知。
为了确定肌球蛋白IC同工型的表达模式，我们对包含同工型特异性序列的两种肌球蛋白IC同工型（同工型A和B）进行了全面的表达分析。通过用同工型特异性抗体进行免疫印迹以及用同工型特异性引物进行qRT-PCR，我们证明肌球蛋白IC同工型A和B在小鼠组织中具有不同的表达模式。具体而言，我们表明肌球蛋白IC同工型A以组织特异性模式表达，而肌球蛋白IC同工型B在小鼠组织中以相当的水平普遍表达。
肌球蛋白IC同工型表达谱的差异表明存在组织特异性MYOIC基因调控，进一步表明肌球蛋白IC同工型尽管具有高度的序列同源性，但可能具有组织特异性和同工型特异性功能。
