Mannervik M, Nibu Y, Zhang H, Levine M
Department of Molecular and Cell Biology, 401 Barker Hall, University of California, Berkeley, CA 94720, USA.
Science. 1999 Apr 23;284(5414):606-9. doi: 10.1126/science.284.5414.606.
Small differences in the levels of an extracellular signaling molecule can specify cell fate during development. Threshold responses are often determined at the level of transcription. Cell-specific and spatially localized patterns of gene expression depend on combinations of sequence-specific activators and repressors that bind to extensive cis-regulatory regions. Different mechanisms for integrating this complex regulatory information are discussed, particularly the role of coregulatory proteins, which are recruited to the DNA template by sequence-specific transcription factors. Recent studies suggest that a growing set of coactivators and corepressors mediate communication between diverse upstream regulatory proteins and the core RNA polymerase II transcription complex.
细胞外信号分子水平的微小差异可在发育过程中决定细胞命运。阈值反应通常在转录水平上确定。基因表达的细胞特异性和空间定位模式取决于与广泛的顺式调控区域结合的序列特异性激活因子和抑制因子的组合。本文讨论了整合这种复杂调控信息的不同机制，特别是共调控蛋白的作用，这些蛋白由序列特异性转录因子招募到DNA模板上。最近的研究表明，越来越多的共激活因子和共抑制因子介导了不同上游调控蛋白与核心RNA聚合酶II转录复合物之间的通讯。
