Phosphorylation and dephosphorylation of spectrin from human erythrocyte ghosts under physiological conditions: autocatalysis rather than reaction with separate kinase and phosphatase.

Détails

ID Serval
serval:BIB_8EB41967B909
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Phosphorylation and dephosphorylation of spectrin from human erythrocyte ghosts under physiological conditions: autocatalysis rather than reaction with separate kinase and phosphatase.
Périodique
Proceedings of the National Academy of Sciences of the United States of America
Auteur(s)
Imhof B.A., Acha-Orbea H.J., Libermann T.A., Reber B.F., Lanz J.H., Winterhalter K.H., Birchmeier W.
ISSN
0027-8424 (Print)
ISSN-L
0027-8424
Statut éditorial
Publié
Date de publication
1980
Volume
77
Numéro
6
Pages
3264-3268
Langue
anglais
Résumé
The mechanism of phosphosylation and dephosphorylation of spectrin from human erythrocyte membranes has been examined under closely physiological conditions. The results support the hypothesis that spectrin is an autophosphorylating and dephosphorylating system. (i) Extraction from ghosts of up to 85% of the kinase (casein kinase) suggested to catalyze the reaction [see Fairbanks, G., Avruch, J., Dino, E. J. & Patel, V. P. (1978) J. Supramol. Struct. 9, 97--112] only slightly reduced spectrin component 2 phosphorylation and did not affect ATP-induced changes in the ghosts' shapes. (ii) A spectrin--actin complex isolated from endocytotic inside-out vesicles under hyperteonic conditions contained virtually no casein kinase activity and still exhibited a largely intact phosphorylation machinery. (iii) Photoaffinity labeling experiments indicated that spectrin component 2 fulfills the necessary prerequisite of the hypothesis--i.e., it contains its own ATP-binding site. (iv) Under various conditions, spectrin phosphorylation and dephospohrylation seem to be tightly coupled. The implications of these findings for the understanding of spectrin function and the maintenance of erythrocyte shape are discussed.
Mots-clé
Actins/metabolism, Adenosine Triphosphate/pharmacology, Affinity Labels/metabolism, Caseins/metabolism, Electrophoresis, Polyacrylamide Gel, Erythrocyte Membrane/enzymology, Erythrocytes/enzymology, Humans, Kinetics, Membrane Proteins/metabolism, Models, Biological, Phosphorylation, Protein Kinase Inhibitors, Protein Kinases/analysis, Sodium Chloride/pharmacology, Spectrin/metabolism, Spectrin/radiation effects, Ultraviolet Rays
Pubmed
Web of science
Création de la notice
24/01/2008 15:48
Dernière modification de la notice
03/03/2018 19:19
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