Yoshikawa T, Makino S, Gao X M, Xing G Q, Chuang D M, Detera-Wadleigh S D
Unit on Gene Mapping and Expression, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA.
Endocrinology. 1996 May;137(5):1562-71. doi: 10.1210/endo.137.5.8612486.
The use of rapid amplification of 5'-cDNA ends-PCR yielded two novel sequences for the rat orphan receptor, TR4, representing heterogeneity on the 5'-untranslated region. Genomic structure analysis revealed that the 5'-untranslated region of the longer messenger RNA fragment, rTR4-1, contained three exons, alpha, beta, and gamma. The skipping of exon gamma gave rise to rTR4-2, indicating that rTR4-1 and rTR4-2 are products of alternative splicing. We isolated another novel rat TR4 splice variant, rTR4-NS, which was found to diverge from rTR4-2 at codon 504. rTR4-NS contained an unspliced intronic sequence with in-frame codons for eight amino acids followed by a termination codon. The three TR4 messenger RNA variants were differentially expressed. rTR4-NS appeared to be a rare transcript found in limited areas of the brain. In situ hybridization detect prominent TR4 signals in brain areas known to be involved in stress response. In cerebellar granule cells, the rise in TR4 expression correlated with the progression of neuronal maturation. N-Methyl-D-aspartate treatment triggered a marked increase in TR4 expression. These results suggest a possible role for TR4 in neuronal differentiation.
运用5'-cDNA末端快速扩增-PCR技术，获得了大鼠孤儿受体TR4的两个新序列，这两个序列在5'-非翻译区存在异质性。基因组结构分析显示，较长信使RNA片段rTR4-1的5'-非翻译区包含三个外显子，即α、β和γ。外显子γ的跳跃产生了rTR4-2，这表明rTR4-1和rTR4-2是选择性剪接的产物。我们分离出了另一种新的大鼠TR4剪接变体rTR4-NS，发现它在第504密码子处与rTR4-2不同。rTR4-NS包含一个未剪接的内含子序列，带有八个氨基酸的读框内密码子，随后是一个终止密码子。这三种TR4信使RNA变体的表达存在差异。rTR4-NS似乎是一种在大脑有限区域发现的稀有转录本。原位杂交在已知参与应激反应的脑区检测到显著的TR4信号。在小脑颗粒细胞中，TR4表达的增加与神经元成熟的进程相关。N-甲基-D-天冬氨酸处理引发了TR4表达的显著增加。这些结果表明TR4在神经元分化中可能发挥作用。
