Activity of nicotinic acid substituted nicotinic acid adenine dinucleotide phosphate (NAADP) analogs in a human cell line: difference in specificity between human and sea urchin NAADP receptors.
Nicotinic acid adenine dinucleotide phosphate (NAADP) is the most potent Ca2+ mobilizing second messenger that has been identified. We have previously shown that NAADP analogs substituted at the 5-position of nicotinic acid were recognized by the sea urchin receptor at low concentration, whereas the 4- substituted analogs were not as potent. However, to date the structure-activity relationship (SAR) of these analogs has not been addressed in mammalian systems. Thus, we asked whether these structurally modified analogs behave similarly in an NAADP-responsive mammalian cell line (SKBR3) using microinjection and single cell fluorescent imaging methods. Novel "caged" 4- and 5-substituted NAADP analogs that were activated inside the cell by flash photolysis resulted in Ca2+ mobilizing activity in SKBR3 cells in a concentration dependent manner, but with reduced effectiveness compared to unmodified NAADP. The SAR in mammalian SKBR3 cells was quite different from that of sea urchin and may suggest that there are differences between NAADP receptors in different species or tissues. Importantly, these data indicate that modifications at the 4- and 5-position of the nicotinic acid ring may lead to the development of functional photoaffinity labels that could be used for receptor localization and isolation in mammalian systems.
Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, University of Toledo Health Sciences Campus, 3000 Arlington Avenue, Toledo, OH 43614, United States.
Ramadan A
RA
Ali
Department of Neurosciences, University of Toledo Health Sciences Campus, 3000 Arlington Avenue, Toledo, OH 43614, United States.
Tetyana
T
Zhelay
Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, University of Toledo Health Sciences Campus, 3000 Arlington Avenue, Toledo, OH 43614, United States.
Christopher J
CJ
Trabbic
Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN 55455, United States.
Timothy F
TF
Walseth
Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, University of Toledo Health Sciences Campus, 3000 Arlington Avenue, Toledo, OH 43614, United States.
James T
JT
Slama
Department of Neurosciences, University of Toledo Health Sciences Campus, 3000 Arlington Avenue, Toledo, OH 43614, United States. Electronic address: david.giovannucci@utoledo.edu.
David R
DR
Giovannucci
Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, University of Toledo Health Sciences Campus, 3000 Arlington Avenue, Toledo, OH 43614, United States. Electronic address: katherine.wall@utoledo.edu.
Katherine A
KA
Wall
D000818:Animals; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects; D045744:Cell Line, Tumor; D005470:Fluorometry; D006801:Humans; D009249:NADP / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D009525:Niacin / Q000737:chemistry*; D009539:Nicotinic Acids / Q000494:pharmacology; D010063:Ovum / Q000187:drug effects / Q000378:metabolism; D010782:Photolysis; D012617:Sea Urchins / Q000254:growth & development / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014466:Ultraviolet Rays
C543818:3-carboxy-1-octylcarbamoylmethylpyridinium; D009539:Nicotinic Acids; D009525:Niacin; D009249:NADP; C024376:NAADP; D002118:Calcium
Antagonists; Ca(2+) signaling; Caged-NAADP; NAADP; SKBR3 cells; Structure–activity relationships