| Summary: | 碩士 === 國立臺灣大學 === 醫學檢驗暨生物技術學研究所 === 96 === Bacterial swarming is a cell-density dependent multicellular surface migration behavior comprising at least swarming lag and actively swarming phases. How the initiation of swarming is regulated remains unknown. Previously we had identified a Serratia marcescens RssA-RssB two-component system regulating swarming. Herein we address the RssA-RssB signaling in swarming development. Activation of RssA-RssB signaling prohibits swarming and once signaling is deactivated, swarming is initiated. RssA-RssB signaling results in phosphorylation of RssB (RssB~P), followed by dissociating itself from the cognate inner membrane sensor kinase RssA and moving into the cytoplasm. RssB~P binds to the -35 region of the rssB promoter, supporting auto-inhibition of RssA-RssB signaling. The downstream genes regulated by RssA-RssB were subsequently identified, including those involved in DNA modification, iron acquisition, sugar transportation, assembly of flagellum and two-component signal transduction. Expression of these genes is coordinately regulated during swarming under RssA-RssB control. We propose that RssA-RssB signaling determines the time when swarming will be initiated and acts as an important temporal regulator in early swarming development.
|
|---|
