1. Dual regulation of atrial natriuretic factor-dependent guanylate cyclase activity by ATP
- Author
-
Rameshwar K. Sharma, Ari Sitaramayya, and Ravi B. Marala
- Subjects
Male ,GUCY1B3 ,Biophysics ,Receptors, Cell Surface ,Second Messenger Systems ,Biochemistry ,Cyclase ,Adenosine Triphosphate ,Structural Biology ,Testis ,otorhinolaryngologic diseases ,Genetics ,Animals ,Cyclic GMP ,Molecular Biology ,GUCY1A2 ,Chemistry ,GUCY1A3 ,Guanylate cyclase activity ,Cell Biology ,Guanylate cyclase 2C ,NPR1 ,ATP-binding protein ,Rats ,Molecular Weight ,Kinetics ,Atrial natriuretic factor receptor guanylate cyclase ,Guanylate Cyclase ,cardiovascular system ,Electrophoresis, Polyacrylamide Gel ,Receptors, Atrial Natriuretic Factor ,Cyclase activity ,Atrial Natriuretic Factor ,hormones, hormone substitutes, and hormone antagonists - Abstract
The ‘second messenger’ of certain atrial natriuretic factor (ANF) signals is cyclic GMP. One type of ANF receptor linked to the synthesis of cyclic GMP is a transmembrane protein which contains both the ANF-binding and guanylate cyclase activities. The consensus is that the maximal activity or this guanylate cyclase is observed in the presence of ATP. We now show that depending upon the cofactors Mg 2+ or Mn 2+ , ATP stimulates or inhibits the ANF-dependent guanylate cyclase activity in the testicular plasma membranes; stimulation in the presence of Mg 2+ and inhibition in the presence of Mn 2+ . With Mg 2+ as cofactor neither ATP nor ANF stimulate the cyclase activity — it is only when the two are together that the enzyme is activated. Furthermore, this investigation for the first time demonstrates binding of ATP to the ANF receptor guanylate cyclase, suggesting that ATP-mediated responses could occur by direct ATP binding to the cyclase.
- Published
- 1991