Furuta, T.; Takeuchi, H.; Isozaki, M.; Takahashi, Y.; Kanehara, M.; Sugimoto, M.; Watanabe, T.; Noguchi, K.; Dore, T. M.; Kurahashi, T.; Iwamura, M.; Tsien, R. Y. Bhc-cNMPs as either water-soluble or membrane-permeant photo-releasable cyclic nucleotides for both one and two-photon excitations.
ChemBioChem 2004,
5, 1119-1128.
Abstract
Cyclic nucleoside monophosphates (cNMPs) play key roles in many cellular regulatory processes, such as growth, differentiation, motility, and gene expression. Caged derivs. that can be activated by irradn. could be powerful tools for studying such diverse functions of intracellular second messengers, since the spatiotemporal dynamics of these mols. can be controlled by irradn. with appropriately focused light. Here we report the synthesis, photochem., and biol. testing of 6-bromo-7-hydroxycoumarin-4-ylmethyl esters of cNMP (Bhc-cNMP) and their acetyl derivs. (Bhc-cNMP/Ac) as new caged second messengers. Irradn. of Bhc-cNMPs quant. produced the parent cNMPs with one-photon uncaging efficiencies (Fe) of up to one order of magnitude better than those of 2-nitrophenethyl (NPE) cNMPs. In addn., two-photon induced photochem. release of cNMP from Bhc-cNMPs (7 and 8) can be obsd. with the two-photon uncaging action cross-sections (delta u) of up to 2.28 GM (1 GM-10-50 cm4s photon-1), which is the largest value among those of the reported Bhc-caged compds. The wavelength dependence of the delta u values of 7 revealed that the peak wavelength was twice that of the one-photon absorption max. Bhc-cNMPs showed practically useful water soly. (nearly 500 micro M), whereas 7-acetylated derivs. (Bhc-cNMPs/Ac) were expected to have a certain membrane permeability. Their advantages were demonstrated in two types of biol. systems: the opening of cAMP-mediated transduction channels in newt olfactory receptor cells and cAMP-mediated motility responses in epidermal melanophores in scales from medaka fish. Both examples showed that Bhc and Bhc/Ac caged compds. have great potential for use in many cell biol. applications. [on SciFinder (R)]