Analysis of a Shigella dysenteriae Fe regulated promoter

描述（由申请人提供）：每年报告数以百万计的志贺氏菌病病例，由志贺氏菌引起。志贺氏菌必须获得所有必需的营养物质，包括铁（Fe），才能在人类宿主中生存并引起疾病。微环境中铁元素的存在会影响志贺菌获取铁所需基因产物的表达（Mills和Payne, 1995； Mills和Payne， 1997）。铁调控基因表达的机制尚不完全清楚。本研究旨在研究铁对痢疾杆菌外膜血红素受体shu基因表达的影响，该基因编码血红素受体，其功能对于痢疾杆菌利用血红素作为营养铁来源至关重要。本提案的具体目的是：1)表征控制痢疾杆菌shu表达的启动子；2)研究fe调控的shu表达的调控机制；3)分析血红素对舒亚蛋白表达的影响。对铁获取的完整理解，包括所涉及的基因和蛋白质，将导致对志贺氏菌在人类宿主内生存和增殖所采用的策略的更全面的认识。

DESCRIPTION (provided by applicant): Millions of cases of shigellosis, caused by the Shigella species, are reported annually. Shigella spp. must acquire all essential nutrients, including iron (Fe), to survive and cause disease within the human host. The presence of Fe within the microenvironment influences the expression of genes whose products are required for Fe acquisition by Shigella (Mills and Payne, 1995; Mills and Payne, 1997). The mechanisms governing Fe regulated gene expression are not fully understood. This proposal aims to characterize the mechanisms controlling the Fe influenced expression of shuA, a gene encoding an outer membrane heme receptor whose function is essential for the utilization of heme as a source of nutrient Fe by S. dysenteriae. The specific aims set forth in this proposal are to: 1) characterize the promoter controlling expression of S. dysenteriae shuA; 2) investigate the mechanisms controlling the Fe-regulated expression of shuA; and 3) analyze the influence of heme on the expression of shuA. A complete understanding of Fe acquisition, including the genes and proteins involved, will lead to a fuller appreciation of the strategies employed by Shigella spp. for survival and proliferation within the human host.