Sandbox Reserved 818: Difference between revisions
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==Mechanism of pertussis toxin== | ==Mechanism of pertussis toxin== | ||
Pertussis toxin acts on target cells through its A protomer which contains the '''enzymatically active S1 subunit'''. <br /> | Pertussis toxin acts on target cells through its A protomer which contains the '''enzymatically active S1 subunit'''. <br /> | ||
This subunit catalyzes [http://en.wikipedia.org/wiki/ADP_ribosylation '''ADP-ribosylation'''] of the ''α-subunit of trimeric G proteins'', which disturbs functions of the target cells and therefore | This subunit catalyzes [http://en.wikipedia.org/wiki/ADP_ribosylation '''ADP-ribosylation'''] of the ''α-subunit of trimeric G proteins'', which disturbs functions of the target cells and therefore leads to various biological effects. | ||
In facts, substrates of PTX are regulators of the membrane-bound [http://en.wikipedia.org/wiki/Adenylate_cyclase adenylate cyclase]. These G proteins bind GTP in order to transduce signals in the cell. When ADP-ribosylation by PTX occurs, ''the downregulation of the adenylate cyclase activity is inhibited''. This inhibition leads to increase [http://en.wikipedia.org/wiki/Cyclic_adenosine_monophosphate cAMP] levels in cells, which explains the amount of biological activities of the toxin. | In facts, substrates of PTX are regulators of the membrane-bound [http://en.wikipedia.org/wiki/Adenylate_cyclase adenylate cyclase]. These G proteins bind GTP in order to transduce signals in the cell. When ADP-ribosylation by PTX occurs, ''the downregulation of the adenylate cyclase activity is inhibited''. This inhibition leads to increase [http://en.wikipedia.org/wiki/Cyclic_adenosine_monophosphate cAMP] levels in cells, which explains the amount of biological activities of the toxin. | ||
