Function
Alpha-toxin has been shown to play a role in pathogenesis of disease, as hla knockout strains show reductions in invasiveness and virulence. Interestingly, the dosage of toxin can result in two different modes of activity. Low concentrations of toxin bind to specific, but unidentified, cell surface receptors and form the heptameric pores. This pore allows the exchange of monovalent ions, resulting in DNA fragmentation and eventually apoptosis. Higher concentrations result in the toxin absorbing nonspecifically to the lipid bilayer and forming large, Ca2+ permissive pores. This in turn results in massive necrosis and other secondary cellular reactions triggered by the uncontrolled Ca2+ influx.
Read more about this topic: Staphylococcus Aureus Alpha Toxin
Famous quotes containing the word function:
“Philosophical questions are not by their nature insoluble. They are, indeed, radically different from scientific questions, because they concern the implications and other interrelations of ideas, not the order of physical events; their answers are interpretations instead of factual reports, and their function is to increase not our knowledge of nature, but our understanding of what we know.”
—Susanne K. Langer (1895–1985)
“Advocating the mere tolerance of difference between women is the grossest reformism. It is a total denial of the creative function of difference in our lives. Difference must be not merely tolerated, but seen as a fund of necessary polarities between which our creativity can spark like a dialectic.”
—Audre Lorde (1934–1992)
“The function of the actor is to make the audience imagine for the moment that real things are happening to real people.”
—George Bernard Shaw (1856–1950)