G18secL03Tpc4: Difference between revisions
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=== Major Hypothesized Functions === | === Major Hypothesized Functions === | ||
*Adaptation and survival in different host environments | *Adaptation and survival in different host environments | ||
Borrelia burgdorferi expresses OspA but not OspC when residing in the midgut of unfed ticks. However, when the tick starts feeding on mammals, OspC synthesis is induced and OspA is repressed.The switch is in part due to the change in temperature; OspC is induced at 32–37°C, but not at 24°C, and this upregulation is at the transcriptional and translational levels. Evidence suggests co-regulation of these two genes at the mRNA level. Clearly, to survive in both hosts, spirochetes have evolved mechanisms for sensing the different host environments and responding accordingly. | Borrelia burgdorferi expresses OspA but not OspC when residing in the midgut of unfed ticks. However, when the tick starts feeding on mammals, OspC synthesis is induced and OspA is repressed.The switch is in part due to the change in temperature; OspC is induced at 32–37°C, but not at 24°C, and this upregulation is at the transcriptional and translational levels. Evidence suggests co-regulation of these two genes at the mRNA level. Clearly, to survive in both hosts, spirochetes have evolved mechanisms for sensing the different host environments and responding accordingly.<ref>D. Kumaran1, S. Eswaramoorthy1, B.J. Luft2, S. Koide3, J.J. Dunn1, C.L. Lawson1,4 and S. Swaminathan1. Crystal structure of outer surface protein C (OspC) from the Lyme disease spirochete, Borrelia burgdorferi.The EMBO Journal (2001) 20, 971 - 978 [http://dx.doi.org/DOI:10.1093/emboj/20.5.971]</ref> | ||
*Binding | *Binding | ||
Although four helical bundle structures may have a variety of functions which are to be defined in further research, OspC may possibly be a binding protein contributing to a fundamental biological process. Several studies have shown that ''B.burgdorferi'' has a predilection for collagenous tissue and can interact with fibronectin and cellular collagens. The spirochetes can bind to a number of different cell types, including fibroblasts. Borrelia burgdorferi can bind to a novel circulating fibroblast-like cell called the peripheral blood fibrocyte, which expresses collagen types I and III as well as fibronectin, in a process that does not require OspA or OspB.<ref>PMID:10072447</ref> | Although four helical bundle structures may have a variety of functions which are to be defined in further research, OspC may possibly be a binding protein contributing to a fundamental biological process. Several studies have shown that ''B.burgdorferi'' has a predilection for collagenous tissue and can interact with fibronectin and cellular collagens. The spirochetes can bind to a number of different cell types, including fibroblasts. Borrelia burgdorferi can bind to a novel circulating fibroblast-like cell called the peripheral blood fibrocyte, which expresses collagen types I and III as well as fibronectin, in a process that does not require OspA or OspB.<ref>PMID:10072447</ref> | ||
