Morozov I Y, Martinez M G, Jones M G, Caddick M X
Plant Science and Fungal Molecular Biology Research Group, School of Biological Sciences, Donnan Laboratories, The University of Liverpool, Crown Street, Liverpool L69 7ZD, UK.
Mol Microbiol. 2000 Sep;37(5):1248-57. doi: 10.1046/j.1365-2958.2000.02085.x.
Nitrogen metabolism in Aspergillus nidulans is regulated by AREA, a member of the GATA family of transcription factors. One mechanism that modulates AREA activity involves the rapid degradation of the areA transcript when sufficient NH4+ or Gln are available. This signalling mechanism has been shown to require a region of 218 nucleotides within the 3' untranslated region of areA mRNA. We demonstrate that this region functions independently in a heterologous transcript and acts to accelerate degradation of the poly(A) tail, which in turn leads to rapid transcript degradation in response to the addition of NH4+ or Gln to the growth medium. areA transcript degradation is inhibited by cycloheximide, but this is not a general consequence of translational inhibition. We believe that this is the first reported example in which specific physiological signals, acting through a defined sequence within a transcript, have been shown to promote accelerated poly(A) degradation, which in turn triggers transcript degradation.
构巢曲霉中的氮代谢由转录因子GATA家族成员AREA调控。调节AREA活性的一种机制涉及当有足够的NH4+或Gln时，areA转录本的快速降解。这种信号传导机制已被证明需要areA mRNA 3'非翻译区内一个218个核苷酸的区域。我们证明该区域在异源转录本中独立发挥作用，并加速poly(A)尾的降解，进而导致在生长培养基中添加NH4+或Gln时转录本快速降解。放线菌酮可抑制areA转录本的降解，但这并非翻译抑制的普遍结果。我们认为这是首次报道的一个例子，其中特定的生理信号通过转录本内的特定序列发挥作用，促进了poly(A)的加速降解，进而触发转录本降解。
