Synthesis of Stable and Cell-type Selective Analogues of Cyclic ADP−Ribose, a Ca²⁺-Mobilizing Second Messenger. Structure−Activity Relationship of the N1-Ribose Moiety¹

Abstract

We previously developed cyclic ADP-carbocyclic ribose (cADPcR, 2) as a stable mimic of cyclic ADP-ribose (cADPR, 1), a Ca(2+)-mobilizing second messenger. A series of the N1-ribose modified cADPcR analogues, designed as novel stable mimics of cADPR, which were the 2"-deoxy analogue 3, the 3"-deoxy analogue 4, the 3"-deoxy-2"-O-(methoxymethyl) analogue 5, the 3"-O-methyl analogue 6, the 2",3"-dideoxy analogue 7, and the 2",3"-dideoxydidehydro analogue 8, were successfully synthesized using the key intramolecular condensation reaction with phenylthiophosphate-type substrates. We investigated the conformations of these analogues and of cADPR and found that steric repulsion between both the adenine and N9-ribose moieties and between the adenine and N1-ribose moieties was a determinant of the conformation. The Ca(2+)-mobilizing effects were evaluated systematically using three different biological systems, i.e., sea urchin eggs, NG108-15 neuronal cells, and Jurkat T-lymphocytes. The relative potency of Ca(2+)-mobilization by these cADPR analogues varies depending on the cell-type used: e.g., 3"-deoxy-cADPcR (4) > cADPcR (2) > cADPR (1) in sea urchin eggs; cADPR (1) >> cADPcR (2) approximately 3"-deoxy-cADPcR (4) in T-cells; and cADPcR (2) > cADPR (1) > 3"-deoxy-cADPcR (4) in neuronal cells, respectively. These indicated that the target proteins and/or the mechanism of action of cADPR in sea urchin eggs, T-cells, and neuronal cells are different. Thus, this study represents an entry to cell-type selective cADPR analogues, which can be used as biological tools and/or novel drug leads.

Cyclic ADP-Carbocyclic-Ribose and -4-Thioribose, as Stable Mimics of Cyclic ADP-Ribose, a Ca²⁺-Mobilizing Second Messenger

“…However, to our surprise, it was inactive in T cells, whereas natural cADPR effectively mobilizes Ca 2+ in both neuronal cells and T cells. 34) These results confirmed that the target proteins and/or the mechanism of action of cADPR in sea urchin eggs, T cells, and neuronal cells are different, 35) as suggested by previous biological studies. [36][37][38][39][40][41][42] …”

New NTP analogs: the synthesis of 4′-thioUTP and 4′-thioCTP and their utility for SELEX

“…This paper constitutes part 235 of Nucleosides and Nucleotides [for part 234 in this series, see (36)]. This work was supported in part by Grant-in-Aid for Scientific Research from the Japan Society for Promotion of Science (No.…”

Measuring Ca2+Release Evoked by Cyclic ADP-Ribose

“…Each of these methods for measuring Ca 2+ release evoked by cADPR (or cADPR analogs) is characterized by specific advantages and weaknesses (Guse et al 1995(Guse et al , 1997(Guse et al , 1999Kunerth et al 2004;Kudoh et al 2005;Xu et al 2006;Steen et al 2007;Kirchberger et al 2009). In the technique using permeabilized cells, 15 × 10 6 cells are present in the cuvette and so the measured response to cADPR is based on a significant cell number.…”