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Autophosphorylation of cGMP‐dependent protein kinase is stimulated only by occupancy of one the two cGMP binding sites
Author(s) -
Hofmann Franz,
Gensheimer Hans-Peter,
Gobel Claus
Publication year - 1983
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(83)80315-9
Subject(s) - autophosphorylation , phosphotransferase , pde10a , protein kinase a , chemistry , protein subunit , binding site , enzyme , phosphodiesterase , biochemistry , kinase , gene
cGMP‐Dependent protein kinase contains, per subunit, 2 binding for cGMP. The apparent K D values for site 1 and 2 were 12 and 55 nM. The analogues 8‐benzyl‐amino‐cAMP and N 2 ‐monobutyryl‐cGMP bind preferentially to site 1 and 2, respectively. Both analogues stimulate autophosphorylation of the enzyme at concentrations at which only half of the phosphotrasferase activity of the enzyme is expressed. Complete expression of the phosphotransferase activity requires a high concentration of each analogue and is accompanied by inhibition of the autophosphorylation reactions. It is concluded that occupancy of site 1 or 2 stimulates autophosphorylation while occupancy of both sites prevents autophosphorylation.