Auxin-Modulated Protein Disulfide-Thiol-Interchange Activity from Soybean Plasma Membranes.
AUTOR(ES)
Morre, D. J.
RESUMO
The renaturation of scrambled (oxidized and inactive) RNase A is catalyzed by soybean (Glycine max cv Williams 82) plasma membranes. The catalysis is stimulated by the auxin herbicide 2,4-dichlorophenoxyacetic acid or by the natural auxin indole-3-acetic acid. The inactive auxin analog, 2,3-dichlorophenoxyacetic acid, is without effect. The activity occurs in the absence of external electron acceptors or donors and therefore appears to be a true disulfide-thiol-interchange activity between protein disulfides and thiols of RNase A and those of plasma membrane proteins. The activity is not affected by a mixture of reduced and oxidized glutathione. However, no auxin-stimulated activity was observed in the presence of either oxidized glutathione or reduced glutathione alone, a response characteristic of the previously described auxin-stimulated NADH oxidase activity of soybean plasma membranes. Taken together, the results suggest the operation in the plant plasma membrane of a protein disulfide-thiol-interchange activity that is stimulated by auxins. The auxin stimulations of the interchange activity are prevented by glutathione, reduced glutathione, and brefeldin A at concentrations that also prevent auxin stimulation of NADH oxidation by isolated plasma membranes and inhibit, as well, the auxin-stimulated elongation of excised segments of soybean hypocotyls.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=157622Documentos Relacionados
- Oxidative metal release from metallothionein via zinc-thiol/disulfide interchange.
- Thiol methyltransferase activity in colonocytes and erythrocyte membranes.
- Insulin, oxytocin, and vasopressin stimulate protein kinase C activity in adipocyte plasma membranes.
- Equilibrium and kinetic constants for the thiol-disulfide interchange reaction between glutathione and dithiothreitol.
- Regulation of pyruvate dehydrogenase kinase activity by protein thiol-disulfide exchange.