Evidence for ATP-ase activity of arrestin from bovine photoreceptors.
In vertebrate photoreceptors the soluble protein arrestin (45 kDa) is involved in controlling the light dependent activity of receptor proteins such as transducin or the cGMP-phosphodiesterase. Arrestin has further been identified as the retinal-S-antigen which is assumed to cause the autoimmune disease uveitis. In a first communication a binding of the nucleotide ATP to arrestin was described. In this subsequent study it is shown that arrestin is also able to hydrolyse ATP at a rate of (5.1 +/- 0.3) x 10(-3) U/mg.min with C1/2 = 93 +/- 5 nM and a Hill coefficient n = 1.8 +/- 0.1 at pH 7.2 and 20 degrees C. These findings suggest a new insight into the process of regulating photoreceptor activity.
Glitscher
W
W
Max-Volmer-Institute, Technical University Berlin, Germany.
Rüppel
H
H
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000494:Allosteric Regulation; D000818:Animals; D000941:Antigens / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D019393:Arrestin; D002417:Cattle; D005136:Eye Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D008970:Molecular Weight; D010786:Photoreceptor Cells / Q000201:enzymology*; D015398:Signal Transduction
D000941:Antigens; D019393:Arrestin; D005136:Eye Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases