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:
“The mother’s and father’s attitudes toward the child correspond to the child’s own needs.... Mother has the function of making him secure in life, father has the function of teaching him, guiding him to cope with those problems with which the particular society the child has been born into confronts him.”
—Erich Fromm (1900–1980)
“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)
“It is the function of vice to keep virtue within reasonable bounds.”
—Samuel Butler (1835–1902)