Dynamic antagonism between ETR-3 and PTB regulates cell type-specific alternative splicing
Dynamic antagonism between ETR-3 and PTB regulates cell type-specific alternative splicing
复制标题
DOI：
10.1016/s1097-2765(02)00479-3
复制
发表时间：
2002-03-01
期刊：
影响因子：
16
通讯作者：
Cooper, TA
中科院分区：
文献类型：
--
作者：
Charlet-B, N;Logan, P;Cooper, TA
在胚胎肌肉中包含心肌肌钙蛋白T（cTNT）外显子5需要保守的侧翼内含子元件（MSE）。ETR-3是CELF家族的成员，在两个MSE中结合U/G基序并在体外直接激活外显子包含。ETR-3的结合和激活被多聚嘧啶束结合蛋白（PTB）直接拮抗。我们使用显性负突变体证明，内源性CELF和PTB活动所需的MSE依赖性激活和抑制肌肉和非肌肉细胞，分别。CELF和PTB显性阴性突变体的组合使用提供了在体内证明在相同细胞内存在拮抗剪接活性。我们的结论是，细胞特异性调节的结果，其中一个积极竞争的监管状态，而不是调制的非监管默认状态的主导地位。
Inclusion of cardiac troponin T (cTNT) exon 5 in embryonic muscle requires conserved flanking intronic elements (MSEs). ETR-3, a member of the CELF family, binds U/G motifs in two MSEs and directly activates exon inclusion in vitro. Binding and activation by ETR-3 are directly antagonized by polypyrimidine tract binding protein (PTB). We use dominant-negative mutants to demonstrate that endogenous CELF and PTB activities are required for MSE-dependent activation and repression in muscle and nonmuscle cells, respectively. Combined use of CELF and PTB dominant-negative mutants provides an in vivo demonstration that antagonistic splicing activities exist within the same cells. We conclude that cell-specific regulation results from the dominance of one among actively competing regulatory states rather than modulation of a nonregulated default state.