Characterization of the A2B adenosine receptor from mouse, rabbit, and dog. J Pharmacol Exp Ther 2009 Apr;329(1):2-13
Date
01/15/2009Pubmed ID
19141710Pubmed Central ID
PMC2670590DOI
10.1124/jpet.108.148270Scopus ID
2-s2.0-63849116251 (requires institutional sign-in at Scopus site) 35 CitationsAbstract
We have cloned and pharmacologically characterized the A(2B) adenosine receptor (AR) from the dog, rabbit, and mouse. The full coding regions of the dog and mouse A(2B)AR were obtained by reverse transcriptase-polymerase chain reaction, and the rabbit A(2B)AR cDNA was obtained by screening a rabbit brain cDNA library. It is noteworthy that an additional clone was isolated by library screening that was identical in sequence to the full-length rabbit A(2B)AR, with the exception of a 27-base pair deletion in the region encoding amino acids 103 to 111 (A(2B)AR(103-111)). This 9 amino acid deletion is located in the second intracellular loop at the only known splice junction of the A(2B)AR and seems to result from the use of an additional 5' donor site found in the rabbit and dog but not in the human, rat, or mouse sequences. [(3)H]3-Isobutyl-8-pyrrolidinoxanthine and 8-[4-[((4-cyano-[2,6-(3)H]-phenyl)carbamoylmethyl)oxy]phenyl]-1,3-di(n-propyl)xanthine ([(3)H]MRS 1754) bound with high affinity to membranes prepared from human embryonic kidney (HEK) 293 cells expressing mouse, rabbit, and dog A(2B)ARs. Competition binding studies performed with a panel of agonist (adenosine and 2-amino-3,5-dicyano-4-phenylpyridine analogs) and antagonist ligands identified similar potency orders for the A(2B)AR orthologs, although most xanthine antagonists displayed lower binding affinity for the dog A(2B)AR compared with A(2B)ARs from rabbit and mouse. No specific binding could be detected with membranes prepared from HEK 293 cells expressing the rabbit A(2B)AR(103-111) variant. Furthermore, the variant failed to stimulate adenylyl cyclase or calcium mobilization. We conclude that significant differences in antagonist pharmacology of the A(2B)AR exist between species and that some species express nonfunctional variants of the A(2B)AR due to "leaky" splicing.
Author List
Auchampach JA, Kreckler LM, Wan TC, Maas JE, van der Hoeven D, Gizewski E, Narayanan J, Maas GEAuthors
John A. Auchampach PhD Professor in the Pharmacology and Toxicology department at Medical College of WisconsinTina C. Wan PhD Research Scientist II in the Pediatrics department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AcetamidesAdenosine
Adenosine A2 Receptor Agonists
Adenosine A2 Receptor Antagonists
Amino Acid Sequence
Animals
Brain Chemistry
Calcium
Cell Line
Cloning, Molecular
Cyclic AMP
DNA, Complementary
Dogs
Humans
Ligands
Mice
Molecular Sequence Data
Purines
RNA, Messenger
Rabbits
Radioligand Assay
Receptor, Adenosine A2B
Reverse Transcriptase Polymerase Chain Reaction
Species Specificity