Identification of Zn2+-dependent and Mg2+/Triton X-100-dependent tyrosine protein kinases in ethylenediaminetetraacetate-treated P2 membrane fraction of monkey brain basal ganglia.
Tyrosine phosphorylation of a 55- and 60-kDa protein was observed when EDTA-treated P2 membrane fraction from monkey basal ganglia was incubated with [gamma-32P]-ATP in the presence of Zn2+. Other metal ions were less effective in this phosphorylation. The effect of Zn2+ did not appear to be due to its inhibition of a tyrosine phosphatase. In the presence of Mg2+/Triton X-100 instead of Zn2+, phosphorylation on tyrosine residues of a 17-kDa protein and the external substrate poly(Glu, Tyr) 4:1 copolymer was observed. Both Mg2+ and Triton X-100 were essential for this and Zn2+ inhibited both of these phosphorylations. Convincing evidence for the existence of Zn2+-dependent and Mg2+/Triton X-100-dependent tyrosine protein kinases was obtained when the two kinases could be separated by extraction of the membranes by Triton X-100. The Zn2+-dependent phosphorylation was present exclusively in the Triton-solubilized supernatant whereas the Mg2+/Triton X-100-dependent phosphorylation was found associated with the Triton-insoluble membrane fractions. Externally added histone could also be phosphorylated on tyrosine residues in a Zn2+- or Mg2+/Triton X-100-dependent manner by the supernatant or membrane fraction, respectively.
Ramamoorthy
S
S
Department of Neurological Sciences, Christian Medical College Hospital, Vellore, India.
Balasubramanian
A S
AS
D000596:Amino Acids / Q000302:isolation & purification; D000818:Animals; D001479:Basal Ganglia / Q000201:enzymology* / Q000378:metabolism; D004492:Edetic Acid; D036341:Intercellular Signaling Peptides and Proteins; D007425:Intracellular Membranes / Q000201:enzymology* / Q000378:metabolism; D008255:Macaca radiata; D008274:Magnesium / Q000502:physiology*; D008970:Molecular Weight; D017830:Octoxynol; D009943:Organophosphorus Compounds / Q000302:isolation & purification; D010455:Peptides / Q000378:metabolism; D010766:Phosphorylation; D011092:Polyethylene Glycols; D011505:Protein-Tyrosine Kinases / Q000302:isolation & purification / Q000378:metabolism*; D012995:Solubility; D015032:Zinc / Q000502:physiology*
D000596:Amino Acids; D036341:Intercellular Signaling Peptides and Proteins; D009943:Organophosphorus Compounds; D010455:Peptides; C027606:L-glutamic acid-L-tyrosine copolymer; D011092:Polyethylene Glycols; D017830:Octoxynol; D004492:Edetic Acid; D011505:Protein-Tyrosine Kinases; D008274:Magnesium; D015032:Zinc