Tropomyosin (Tpm) is an actin-associated protein and key regulator of actin filament structure and dynamics in muscle and non-muscle cells where it participates in many vital processes. Human non-muscle cells produce many Tpm isoforms; however, little is known yet about their structural and functional properties. In the present work, we have applied various methods to investigate the properties of five low molecular weight Tpm isoforms (Tpm3.1, Tpm3.2, Tpm3.4, Tpm3.5, and Tpm3.7), the products of TPM3 gene, which significantly differ by alternatively spliced internal exon 6 (6a or 6b) and C-terminal exon 9 (9a, 9c or 9d). Our results clearly demonstrate that the properties of these Tpm isoforms are quite different depending on sequence variations in alternatively spliced regions of their molecules. These differences can be important in further studies to explain why these Tpm isoforms play a key role in organization and dynamics of the cytoskeleton.

原肌球蛋白 (Tpm) 是一种肌动蛋白相关蛋白，是肌肉和非肌肉细胞中肌动蛋白丝结构和动力学的关键调节剂，它参与许多重要过程。人类非肌肉细胞产生许多 Tpm 亚型；然而，人们对其结构和功能特性知之甚少。在目前的工作中，我们已应用各种方法研究了五种低分子量 Tpm 异构体（Tpm3.1、Tpm3.2、Tpm3.4、Tpm3.5 和 Tpm3.7）的特性，它们是TPM3的产物基因，其显着差异在于可变剪接的内部外显子 6（6a 或 6b）和 C 端外显子 9（9a、9c 或 9d）。我们的结果清楚地表明，这些 Tpm 同种型的特性非常不同，这取决于其分子可变剪接区域的序列变化。这些差异在进一步研究中很重要，可以解释为什么这些 Tpm 同种型在细胞骨架的组织和动力学中起着关键作用。