Regulatory differences among avian ecto-ATPases.
Extracellular ATP is found to produce a variety of important biological responses. Ecto-ATPases are located on numerous cell types in many different species, regulate extracellular ATP levels and can be a key step in generating adenosine. Studies conducted on chicken ecto-ATPases from liver and cardiac and smooth muscle show a variety of differing properties including (1) different apparent Km's, (2) lectin sensitivity, (3) responses to detergents, (4) responses to lipid mediators, and (5) responsiveness to nucleotide-mimetic affinity labels. These results suggest that although each enzyme hydrolyzes extracellular ATP, they should each be viewed as a distinct subtype of the whole ecto-ATPase family due to their differential responses, largely linked to proposed regulatory phenomenon.
Caldwell
C
C
Department of Chemistry, Molecular Biology Institute, San Diego State University, California 92182, USA.
Norman
V
V
Urbina
A
A
Jarvis
A
A
Quinonez
C
C
Stemm
M
M
Dahms
A S
AS
D000251:Adenosine Triphosphatases / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002645:Chickens; D003208:Concanavalin A / Q000494:pharmacology; D003902:Detergents; D019852:Diacylglycerol Kinase / Q000037:antagonists & inhibitors; D004923:Erythrosine / Q000494:pharmacology; D007700:Kinetics; D050356:Lipid Metabolism; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology; D009124:Muscle Proteins / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D009130:Muscle, Smooth / Q000187:drug effects / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology; D017830:Octoxynol; D012995:Solubility; D013110:Sphingosine / Q000031:analogs & derivatives / Q000494:pharmacology
D003902:Detergents; D009124:Muscle Proteins; D003208:Concanavalin A; D000255:Adenosine Triphosphate; D017830:Octoxynol; D019852:Diacylglycerol Kinase; D000251:Adenosine Triphosphatases; C027201:ectoATPase; C061800:N,N-dimethylsphingosine; D013110:Sphingosine; D004923:Erythrosine