Lewis-Tuffin Laura J, Quinn Patrick G, Chikaraishi Dona M
Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
Mol Cell Neurosci. 2004 Mar;25(3):536-47. doi: 10.1016/j.mcn.2003.10.010.
In neurons and neuroendocrine cells, tyrosine hydroxylase (TH) gene expression is induced by stimuli that elevate cAMP, by depolarization, and by hypoxia. Using these stimuli, we examined TH promoter mutants, cAMP response element binding protein (CREB) phosphorylation site mutants, and transcriptional interference with dominant negative transcription factors to assess the relative contributions of CREB/AP-1 family members to the regulation of basal and inducible TH transcription in PC12 cells. We found that basal transcription depends on transcription factor activity at the partial dyad (-17 bp), CRE (-45 bp), and AP1 (-205 bp) elements. Induced transcription is regulated primarily by activity at the CRE, with only small contributions from the AP1 or hypoxia response element 1 (HRE1; -225 bp) elements, regardless of inducing stimulus. CREB, ATF-1, and CREMtau all mediate CRE-dependent transcription, with CREB and CREMtau being more effective than ATF-1. Phosphorylation of CREB on Ser133, but not on Ser142 or Ser143, is required for induced transcription, regardless of inducing stimulus.
在神经元和神经内分泌细胞中，酪氨酸羟化酶（TH）基因表达可由提高环磷酸腺苷（cAMP）的刺激、去极化和缺氧诱导。利用这些刺激，我们检测了TH启动子突变体、cAMP反应元件结合蛋白（CREB）磷酸化位点突变体，以及与显性负转录因子的转录干扰，以评估CREB/激活蛋白-1（AP-1）家族成员对PC12细胞中基础和诱导性TH转录调控的相对贡献。我们发现基础转录依赖于部分二分体（-17 bp）、CRE（-45 bp）和AP1（-205 bp）元件处的转录因子活性。诱导转录主要由CRE处的活性调控，无论诱导刺激如何，AP1或缺氧反应元件1（HRE1；-225 bp）元件的贡献都很小。CREB、活化转录因子-1（ATF-1）和CREMtau均介导CRE依赖性转录，其中CREB和CREMtau比ATF-1更有效。无论诱导刺激如何，诱导转录都需要CREB在丝氨酸133而非丝氨酸142或丝氨酸143处的磷酸化。
