Wang Hao-Ven, Moser Markus
Max-Planck-Institute of Biochemistry, Department of Molecular Medicine, Martinsried, Germany.
Dev Dyn. 2008 Nov;237(11):3342-51. doi: 10.1002/dvdy.21755.
Palladin fulfils a crucial function as a molecular scaffold in organizing and stabilizing the actin cytoskeleton. At least four major palladin isoforms exist due to different promoter usage and alternative splicing: a 200-kDa isoform, a 140-kDa isoform, and two isoforms with a size of 90-92 kDa. Here, we describe their expression during mouse development and in adult tissues. The 200-kDa isoform is predominantly expressed in developing heart and skeletal muscle. The 140-kDa isoform is expressed in various mesenchymal tissues, and also represents the major isoform of the brain. The 90-92-kDa isoforms are almost ubiquitously expressed with the highest levels in smooth muscle-rich tissues. Immunohistochemical and immunofluorecence staining with an anti-200-kDa isoform-specific antiserum localizes the large isoform to the Z-discs of cardiac and skeletal muscle cells. Interestingly, the expression of this isoform is initiated and increasing during in vitro differentiation and fusion of C2C12 myoblasts, suggesting that the 200-kDa palladin isoform may play a scaffolding role during sarcomeric organization.
帕拉丁作为一种分子支架，在组织和稳定肌动蛋白细胞骨架方面发挥着关键作用。由于启动子使用和可变剪接的不同，至少存在四种主要的帕拉丁异构体：一种200 kDa的异构体、一种140 kDa的异构体以及两种大小为90 - 92 kDa的异构体。在此，我们描述它们在小鼠发育过程和成年组织中的表达情况。200 kDa的异构体主要在发育中的心脏和骨骼肌中表达。140 kDa的异构体在各种间充质组织中表达，也是大脑的主要异构体。90 - 92 kDa的异构体几乎在所有组织中都有表达，在富含平滑肌的组织中表达水平最高。用抗200 kDa异构体特异性抗血清进行免疫组织化学和免疫荧光染色，可将这种大型异构体定位到心肌和骨骼肌细胞的Z盘。有趣的是，在C2C12成肌细胞的体外分化和融合过程中，这种异构体的表达开始并增加，这表明200 kDa的帕拉丁异构体可能在肌节组织过程中发挥支架作用。
