cGMP mobilizes intracellular Ca2+ in sea urchin eggs by stimulating cyclic ADP-ribose synthesis.
Many hormones or neurotransmitters act at cell surface receptors to increase the intracellular free calcium concentration, triggering a wide range of cellular responses. As the source of this Ca2+ is often internal stores, additional messengers are required to convey the hormonal message from the plasma membrane. Cyclic ADP-ribose (cADPR) has been proposed as the endogenous activator of Ca(2+)-induced Ca2+ release by the ryanodine receptor in sea urchin eggs and in several mammalian cell types. A second messenger role for cADPR requires that its intracellular levels be under the control of extracellular stimuli. Here we demonstrate a novel action of 3',5'-cyclic guanosine monophosphate (cGMP) in stimulating the synthesis of cADPR from beta-NAD+ by activating its synthetic enzyme ADP-ribosyl cyclase in sea urchin eggs and egg homogenates. We suggest that cADPR may transduce signals generated by cell surface receptors or gaseous transmitters linked to cGMP production.
Galione
A
A
University Department of Pharmacology, University of Oxford, UK.
White
A
A
Willmott
N
N
Turner
M
M
Potter
B V
BV
Watson
S P
SP
D000246:Adenosine Diphosphate Ribose / Q000031:analogs & derivatives* / Q000096:biosynthesis; D000814:Aniline Compounds; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D036563:Cyclic ADP-Ribose; D006152:Cyclic GMP / Q000378:metabolism*; D005470:Fluorometry; D066298:In Vitro Techniques; D008861:Microsomes / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D010063:Ovum; D012430:Ruthenium Red; D012617:Sea Urchins; D015398:Signal Transduction; D014966:Xanthenes
D000814:Aniline Compounds; D014966:Xanthenes; D009243:NAD; D012430:Ruthenium Red; D036563:Cyclic ADP-Ribose; D000246:Adenosine Diphosphate Ribose; C059715:Fluo-3; D006152:Cyclic GMP; D002118:Calcium