Protein kinase-dependent phosphorylation of the Menkes copper P-type ATPase.

Autor: Voskoboinik I; Department of Genetics, The University of Melbourne, Melbourne, Vic. 3010, Australia., Fernando R, Veldhuis N, Hannan KM, Marmy-Conus N, Pearson RB, Camakaris J
Jazyk: angličtina
Zdroj: Biochemical and biophysical research communications [Biochem Biophys Res Commun] 2003 Mar 28; Vol. 303 (1), pp. 337-42.
DOI: 10.1016/s0006-291x(03)00329-2
Abstrakt: The Menkes copper-translocating P-type ATPase (ATP7A; MNK) is a key regulator of copper homeostasis in humans. It has a dual role in supplying copper to essential cuproenzymes in the trans-Golgi network (TGN) and effluxing copper from the cell. These functions are achieved through copper-regulated trafficking of MNK between the TGN and the plasma membrane. However, the exact mechanism(s) which regulate the localisation and biochemical functions of MNK are still unknown. Here we investigated copper-dependent phosphorylation of MNK by a putative protein kinase(s). We found that in the presence of elevated copper there was a substantial increase in phosphorylation of the wild-type MNK in vivo. The majority of copper-dependent phosphorylation was on serine residues in two phosphopeptides. In contrast, there was no up-regulation of phosphorylation of a non-trafficking MNK mutant with mutated cytosolic copper-binding sites. Our findings suggest a potentially important role of kinase-dependent phosphorylation in the regulation of function of the MNK protein.
Databáze: MEDLINE