Titre
Sequential phosphorylation of protein band 3 by Syk and Lyn tyrosine kinases in intact human erythrocytes: identification of primary and secondary phosphorylation sites.
Type
article
Institution
Externe
Périodique
Auteur(s)
Brunati, A.M.
Auteure/Auteur
Bordin, L.
Auteure/Auteur
Clari, G.
Auteure/Auteur
James, P.
Auteure/Auteur
Quadroni, M.
Auteure/Auteur
Baritono, E.
Auteure/Auteur
Pinna, L.A.
Auteure/Auteur
Donella-Deana, A.
Auteure/Auteur
Liens vers les personnes
ISSN
0006-4971
Statut éditorial
Publié
Date de publication
2000-08
Volume
96
Numéro
4
Première page
1550
Dernière page/numéro d’article
1557
Peer-reviewed
Oui
Langue
anglais
Résumé
Treatment of intact human erythrocytes with pervanadate induces Tyr (Y)-phosphorylation of the transmembrane protein band 3; in parallel, the activity of the immunoprecipitated tyrosine kinases Syk and Lyn is increased. When erythrocytes are incubated with pervanadate together with PP1, a specific inhibitor of Src kinases, including Lyn, the Y-phosphorylation of band 3 is only partially reduced. Indeed, the PP1-resistant phosphorylation of band 3 precedes and is a prerequisite for its coimmunoprecipitation with Lyn, which interacts with the phosphoprotein via the SH2 domain of the enzyme, as proven by binding competition experiments. Upon recruitment to primarily phosphorylated band 3, Lyn catalyzes the secondary phosphorylation of the transmembrane protein. These data are consistent with the view that band 3 is phosphorylated in intact erythrocytes by both PP1-resistant (most likely Syk) and PP1-inhibited (most likely Lyn) tyrosine kinases according to a sequential phosphorylation process. Similar radiolabeled peptide maps are obtained by tryptic digestion of (32)P-band 3 isolated from either pervanadate-treated erythrocytes or red cell membranes incubated with exogenous Syk and Lyn. It has also been demonstrated by means of mass spectrometry that the primary phosphorylation of band 3 occurs at Y8 and Y21, while the secondary phosphorylation affects Y359 and Y904. (Blood. 2000;96:1550-1557)
PID Serval
serval:BIB_97A1DDD703AE
PMID
Date de création
2008-01-24T14:46:25.502Z
Date de création dans IRIS
2025-05-21T00:13:14Z