The messenger function of calcium in cell activation.
D000262:Adenylyl Cyclases / Q000502:physiology; D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000502:physiology*; D002135:Calcium-Binding Proteins / Q000378:metabolism; D000242:Cyclic AMP / Q000502:physiology; D003593:Cytoplasm / Q000502:physiology; D004910:Erythrocyte Membrane / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D007257:Information Theory; D008566:Membranes / Q000502:physiology*; D008928:Mitochondria / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D011955:Receptors, Drug / Q000502:physiology*
D002135:Calcium-Binding Proteins; D010710:Phosphates; D011955:Receptors, Drug; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D002118:Calcium