Analysis of molecules related to structure and function of T-tubule in cardiac myocytes

横小管（T-tubule）是质膜的内陷部分，仅见于心室肌和骨骼肌细胞，在兴奋和收缩偶联中起重要作用。为了鉴定参与心肌细胞T-小管结构形成和维持的分子，通过北方印迹法测定候选基因的mRNA表达。在所检测的基因中，F-BAR蛋白家族成员Pacsin 3在成人心室肌细胞中高表达。为了揭示Pacsin 3的功能，将几种缺失突变体瞬时转染COS 7细胞。Pacsin 3 C端缺失突变体与α-微管蛋白共定位，改变了微管网络的形态。

Transverse-tubule (T-tubule) is invagination of plasma membrane, only found in ventricular and skeletal myocytes, and have important role for excitation and contraction coupling. To identify molecules involved in formation and maintain of T-tubule structure in cardiac myocyte, mRNA expression of candidate genes were determined by Northern blotting. Among the genes tested, Pacsin3, a member of F-BAR protein family, was highly expressed in adult ventricular myocyte. To reveal the functions of Pacsin3, several deletion mutants was transiently transfected in COS7 cell. C-terminal deletion mutant of Pacsin3 was co-localized with alpha-tubulin, and changed form of microtubule network.