Stamm S, Casper D, Lees-Miller J P, Helfman D M
Cold Spring Harbor Laboratory, NY 11724.
Proc Natl Acad Sci U S A. 1993 Nov 1;90(21):9857-61. doi: 10.1073/pnas.90.21.9857.
In this study we report on the developmental and regional expression of two brain-specific isoforms of tropomyosin, TMBr-1 and TMBr-3, that are generated from the rat alpha-tropomyosin gene via the use of alternative promoters and alternative RNA splicing. Western blot analysis using an exon-specific peptide polyclonal antibody revealed that the two isoforms are differentially expressed in development with TMBr-3 appearing in the embryonic brain at 16 days of gestation, followed by the expression of TMBr-1 at 20 days after birth. TMBr-3 was detected in all brain regions examined, whereas TMBr-1 was detected predominantly in brain areas that derived from the prosencephalon. Immunocytochemical studies on mixed primary cultures made from rat embryonic midbrain indicate that expression of the brain-specific epitope is restricted to neurons. The developmental pattern and neuronal localization of these forms of tropomyosin suggest that these isoforms have a specialized role in the development and plasticity of the nervous system.
在本研究中，我们报告了原肌球蛋白的两种脑特异性同工型TMBr-1和TMBr-3的发育及区域表达情况，它们是通过使用不同的启动子和选择性RNA剪接从大鼠α-原肌球蛋白基因产生的。使用外显子特异性肽多克隆抗体进行的蛋白质印迹分析表明，这两种同工型在发育过程中差异表达，TMBr-3在妊娠16天时出现在胚胎脑中，随后在出生后20天时表达TMBr-1。在所检查的所有脑区中均检测到TMBr-3，而TMBr-1主要在源自前脑的脑区中检测到。对大鼠胚胎中脑混合原代培养物进行的免疫细胞化学研究表明，脑特异性表位的表达仅限于神经元。这些原肌球蛋白形式的发育模式和神经元定位表明，这些同工型在神经系统的发育和可塑性中具有特殊作用。
