一种新型心脏特异性原肌球蛋白同工型在人类中的表达。

Expression of a novel cardiac-specific tropomyosin isoform in humans.

作者信息

Denz Christopher R, Narshi Aruna, Zajdel Robert W, Dube Dipak K

机构信息

Department of Cell and Developmental Biology, SUNY Upstate Medical Univeristy, 750 East Adams St., Syracuse, NY 13210, USA.

出版信息

Biochem Biophys Res Commun. 2004 Aug 6;320(4):1291-7. doi: 10.1016/j.bbrc.2004.06.084.

DOI:10.1016/j.bbrc.2004.06.084

PMID:15249230

Abstract

Tropomyosins are a family of actin binding proteins encoded by a group of highly conserved genes. Humans have four tropomyosin-encoding genes: TPM1, TPM2, TPM3, and TPM4, each of which is known to generate multiple isoforms by alternative splicing, promoters, and 3' end processing. TPM1 is the most versatile and encodes a variety of tissue specific isoforms. The TPM1 isoform specific to striated muscle, designated TPM1alpha, consists of 10 exons: 1a, 2b, 3, 4, 5, 6b, 7, 8, and 9a/b. In this study, using RT-PCR with adult and fetal human RNAs, we present evidence for the expression of a novel isoform of the TPM1 gene that is specifically expressed in cardiac tissues. The new isoform is designated TPM1kappa and contains exon 2a instead of 2b. Ectopic expression of human GFP.TPM1kappa fusion protein can promote myofibrillogenesis in cardiac mutant axolotl hearts that are lacking in tropomyosin.

摘要

原肌球蛋白是一类由一组高度保守基因编码的肌动蛋白结合蛋白。人类有四个编码原肌球蛋白的基因：TPM1、TPM2、TPM3和TPM4，已知每个基因通过可变剪接、启动子和3'端加工产生多种异构体。TPM1是最具通用性的，编码多种组织特异性异构体。横纹肌特有的TPM1异构体，命名为TPM1α，由10个外显子组成：1a、2b、3、4、5、6b、7、8和9a/b。在本研究中，我们使用成人和胎儿人类RNA进行逆转录聚合酶链反应（RT-PCR），为TPM1基因一种在心脏组织中特异性表达的新型异构体的表达提供了证据。这种新的异构体命名为TPM1κ，包含外显子2a而非2b。人绿色荧光蛋白-TPM1κ融合蛋白的异位表达可促进缺乏原肌球蛋白的心脏突变蝾螈心脏中的肌原纤维形成。