Yoo H S, Cooper T G
Department of Microbiology and Immunology, University of Tennessee, Memphis 38163.
Mol Cell Biol. 1989 Aug;9(8):3231-43. doi: 10.1128/mcb.9.8.3231-3243.1989.
Expression of the allantoin system genes in Saccharomyces cerevisiae is induced by allophanate or its analog, oxalurate. This work provides evidence for the involvement of distinct types of cis-acting elements in the induction process. The first element was found to have the properties of an upstream activation sequence (UAS). This element was localized to a 16-base-pair (bp) DNA fragment containing a short 5-bp sequence that occurred repeatedly in the upstream region of DAL7. When present in two or more copies, the 16-bp fragment supported high-level beta-galactosidase production in a CYC1-lacZ expression vector; there was, however, no response to the allantoin pathway inducer. The second element had the properties of a negatively acting element or upstream repression sequence (URS). This element was localized to a 16-bp DNA fragment containing an 8-bp sequence that was repeated four times in the upstream region of DAL7. A fragment containing the 8-bp repeated sequence placed adjacent to the UAS-containing fragment mediated inhibition of the ability of the UAS to support lacZ expression regardless of whether inducer was present. A third element, designated an upstream induction sequence (UIS), was required for response to inducer. The UIS was localized to a small DNA fragment containing an approximately 10-bp sequence that was repeated twice in the upstream region of DAL7. When a fragment containing the 10-bp repeated sequence was placed adjacent to these UAS and URS elements, the construction (UIS-UAS-URS) supported normal oxalurate-mediated induction of beta-galactosidase synthesis. These data are consistent with the suggestion that multiple, cis-acting elements participate in the induction process.
尿囊素系统基因在酿酒酵母中的表达可由脲基甲酸酯或其类似物草尿酸诱导。这项工作为不同类型的顺式作用元件参与诱导过程提供了证据。第一个元件被发现具有上游激活序列（UAS）的特性。该元件定位于一个16个碱基对（bp）的DNA片段，其中包含一个短的5个碱基对序列，该序列在DAL7的上游区域重复出现。当以两个或更多拷贝存在时，16个碱基对的片段在CYC1-lacZ表达载体中支持高水平的β-半乳糖苷酶产生；然而，对尿囊素途径诱导剂没有反应。第二个元件具有负作用元件或上游抑制序列（URS）的特性。该元件定位于一个16个碱基对的DNA片段，其中包含一个8个碱基对序列，该序列在DAL7的上游区域重复出现四次。一个包含8个碱基对重复序列的片段与包含UAS的片段相邻放置，无论是否存在诱导剂，都介导了UAS支持lacZ表达能力的抑制。第三个元件，称为上游诱导序列（UIS），是对诱导剂作出反应所必需的。UIS定位于一个小的DNA片段，其中包含一个大约10个碱基对的序列，该序列在DAL7的上游区域重复出现两次。当一个包含10个碱基对重复序列的片段与这些UAS和URS元件相邻放置时，构建体（UIS-UAS-URS）支持草尿酸介导的β-半乳糖苷酶合成的正常诱导。这些数据与多个顺式作用元件参与诱导过程的观点一致。
