Regulation of cADPR Synthesis

which elevates cGMP levels in the sea urchin egg, probably by activating soluble guanylate cyclases, also leads to Ca2+ mobilization in both intact eggs (Fig. 3) and egg homogenates (Willmott et al, 

with a pharmacology suggesting that it activates a pathway involving both cGMP and cADPR (Lee, 1994). It will be interesting to see if such a pathway operates in mammalian cells too. 

Important tools in studying cADPR-mediated Ca + mobilization have been the use of 8-substituted analogues of cADPR (Walseth and Lee, 1993). 8-Amino-, 

8-bromo-, and 8-azido-cADPR can be synthesized by incubating their respective 8-substituted NAD+ ana- 

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