Evidence for a regulatory action of vanadate on protein phosphorylation in brain microvessels.
We investigated the action of vanadate on protein phosphorylation in microvessels isolated from rat brain. We found that a stimulation of protein phosphorylation from 32P-ATP occurs, in the presence of different concentrations of vanadate, 10(-3) M being the most effective dose. This action was time-dependent, and it was more evident after 60 s of treatment. The contribution of ATPase inhibition caused by vanadate appears to be negligible. In addition a stimulation of cAMP-dependent protein kinase activity was observed. The pattern of protein phosphorylation showed that exposure to 10(-3) M vanadate resulted in a nonspecific stimulation of protein phosphorylation concomitantly with a selective inhibition of the 55 KDa protein phosphorylation. The nature of this protein is also discussed.
Catalán
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RE
Departamento de Biología Molecular, Universidad Autónoma de Madrid, Spain.
Martínez
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AM
Aragonés
M D
MD
Díaz
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D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000098:blood supply* / Q000201:enzymology; D006868:Hydrolysis; D008297:Male; D008833:Microcirculation / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014638:Vanadates / Q000494:pharmacology*
D011506:Proteins; D014638:Vanadates; D011494:Protein Kinases