Peters M H, Beltzer J P, Kohlhaw G B
Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907.
Arch Biochem Biophys. 1990 Jan;276(1):294-8. doi: 10.1016/0003-9861(90)90041-v.
A translational fusion of yeast LEU4 and Escherichia coli lacZ which contains 679 bp of the LEU4 5'-flanking region and the first two codons of LEU4 was used to study LEU4 expression. Eight recipient strains with different genetic backgrounds, transformed with a plasmid containing the fusion, were grown under a variety of conditions, and beta-galactosidase activity was measured. Evidence was obtained for at least four modes of expression of LEU4: general amino acid control, leucine-specific control, basal level expression, and branched-chain amino acid-mediated repression. Determination of steady-state levels of LEU4 mRNA suggested that LEU4 expression is regulated transcriptionally.
含有679bp的LEU4 5'侧翼区和LEU4前两个密码子的酵母LEU4与大肠杆菌lacZ的翻译融合体用于研究LEU4的表达。用含有该融合体的质粒转化的八种具有不同遗传背景的受体菌株在多种条件下生长，并测定β-半乳糖苷酶活性。获得了关于LEU4至少四种表达模式的证据：一般氨基酸控制、亮氨酸特异性控制、基础水平表达和支链氨基酸介导的阻遏。LEU4 mRNA稳态水平的测定表明LEU4的表达受转录调控。
