After axon outgrowth and synapse formation, the nervous system transitions to a stable architecture. In C. elegans, this transition is marked by the appearance of casein kinase 1δ (CK1δ) in the nucleus. In CK1δ mutants, neurons continue to sprout growth cones into adulthood, leading to a highly ramified nervous system. Nervous system architecture in these mutants is completely restored by suppressor mutations in ten genes involved in transcription termination. CK1δ prevents termination by phosphorylating and inhibiting SSUP-72. SSUP-72 would normally remodel the C-terminal domain of RNA polymerase in anticipation of termination. The antitermination activity of CK1δ establishes the mature state of a neuron by promoting the expression of the long isoform of a single gene, the cytoskeleton protein Ankyrin.

中文翻译：

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酪蛋白激酶1δ通过抑制锚蛋白的转录终止来稳定成熟的轴突。

在轴突生长和突触形成后，神经系统转变为稳定的结构。在秀丽隐杆线虫中，这种转变以酪蛋白激酶1δ（CK1δ）在细胞核中的出现为标志。在CK1δ突变体中，神经元继续向成年期生长，生长锥体，导致神经系统高度分支。这些突变体中的神经系统结构可通过转录终止中涉及的十个基因的抑制子突变而完全恢复。CK1δ通过磷酸化和抑制SSUP-72来防止终止。SSUP-72通常会在预期终止时重塑RNA聚合酶的C末端结构域。CK1δ的抗终止活性通过促进单个基因（细胞骨架蛋白锚蛋白）长同种型的表达而建立神经元的成熟状态。