Zusammenfassung der Ressource
Adenylyl Cyclase Pathway
- Adenylyl Cyclase = membrane-bound enzyme.
- catalyses the synthesis of cAMP from ATP.
- cAMP = 2nd messenger
- activates protein kinase cascades e.g.PKA.
- Activation of adenylyl cyclase and thus cAMP levels is
proportional to the total concentration of G-alpha subunits
that are bound to GTP
- Positive and Negative Regulation of
Adenylyl Cyclase Activity provides fine
tuning for levels of cAMP.
- An example?
- The PKA mediated effects of cardiac myocytes
- voltage-gated calcium channels in myocytes are
either unavailble (electically unexcitable) or
availble (electrically excitable)
- Norepinarphrine acts as the
1st messenger
- acts at beta-adrenergic receptors
- Which are coupled to G-proteins
- Adynylylcyclase acts as the effector protein
- The synthesis of cAMP is catalysed (from ATP)
- and PKA is the late effector protein
- PKA has the ability to make the
Ca2+ channels in myocytes
electrically excitable (i.e.availble)