细胞核中转录因子维持活性状态时间的长短对于调节基因转录非常重要。能够识别核定位信号 (ＮＬＳ)和核输出信号(ＮＥＳ)的蛋白质可以分别使转录因子或调节转录因子活性的酶转进或转出细胞核。ＮＥＳ和ＮＬＳ的相对通达可经下列方式调节 :第一 ,通过对邻近氨基酸残基的翻译后修 The length of time the transcription factor remains active in the nucleus is important for regulating gene transcription. Proteins that recognize the nuclear localization signal (NLS) and nuclear output signal (NES) can respectively turn transcription factors or enzymes that regulate the activity of a transcription factor into or out of the nucleus. The relative accessibility of NES and NLS can be adjusted as follows: First, through the post-translational repair of adjacent amino acid residues