Magasanik Boris, Kaiser Chris A
Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Gene. 2002 May 15;290(1-2):1-18. doi: 10.1016/s0378-1119(02)00558-9.
Yeast cells can respond to growth on relatively poor nitrogen sources by increasing expression of the enzymes for the synthesis of glutamate and glutamine and by increasing the activities of permeases responsible for the uptake of amino acids for use as a source of nitrogen. These general responses to the quality of nitrogen source in the growth medium are collectively termed nitrogen regulation. In this review, we discuss the historical foundations of the study of nitrogen regulation as well as the current understanding of the regulatory networks that underlie nitrogen regulation. One focus of the review is the array of four GATA type transcription factors which are responsible for the regulation the expression of nitrogen-regulated genes. They are the activators Gln3p and Nil1p and their antagonists Nil2p and Dal80p. Our discussion includes consideration of the DNA elements which are the targets of the transcription factors and of the regulated translocation of Gln3p and Nil1p from the cytoplasm to the nucleus. A second focus of the review is the nitrogen regulation of the general amino acid permease, Gap1p, and the proline permease, Put4p, by ubiquitin mediated intracellular protein sorting in the secretory and endosomal pathways.
酵母细胞可以通过增加谷氨酸和谷氨酰胺合成酶的表达，以及增加负责摄取氨基酸作为氮源的通透酶的活性，来响应在相对贫瘠的氮源上的生长。这些对生长培养基中氮源质量的一般反应统称为氮调节。在这篇综述中，我们讨论了氮调节研究的历史基础以及对氮调节基础的调控网络的当前理解。综述的一个重点是负责调控氮调节基因表达的四种GATA型转录因子。它们是激活因子Gln3p和Nil1p及其拮抗剂Nil2p和Dal80p。我们的讨论包括对作为转录因子靶标的DNA元件以及Gln3p和Nil1p从细胞质到细胞核的调控易位的考虑。综述的第二个重点是泛素介导的分泌和内体途径中的细胞内蛋白质分选对一般氨基酸通透酶Gap1p和脯氨酸通透酶Put4p的氮调节。
