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			PubMed Journals: J Biol Chem

  Source:		PMID: 11502746


    		J Biol Chem. 2001 Nov 2;276(44):40411-6.
     		Epub 2001 Aug 13.

			Phosphorylation of Ser(19) alters the conformation
			of tyrosine hydroxylase to increase the
			rate of phosphorylation of Ser(40).

			Bevilaqua LR(1), Graham ME, Dunkley PR,
			von Nagy-Felsobuki EI, Dickson PW.

			Author Information
			(1) School of Biomedical Sciences, Faculty
			of Medicine and Health Sciences, The University
			of Newcastle, Callaghan, New South Wales
			2308, Australia.

			The effect of phosphorylation on the shape
			of tyrosine hydroxylase (TH) was studied
			directly using gel filtration and indirectly
			using electrospray ionization mass spectrometry.
			Phosphorylation of Ser(19) and Ser(40) produced
			a TH molecule with a more open conformation
			than the non-phosphorylated form. The conformational
			effect of Ser(19) phosphorylation is less
			pronounced than that of the Ser(40) phosphorylation.
			The effect of Ser(19) and Ser(40) phosphorylation
			appears to be additive. Binding of dopamine
			produced a more compact form when compared
			with the non-dopamine-bound TH. The interdependence
			of Ser(19) and Ser(40) phosphorylation was
			probed using electrospray ionization mass
			spectrometry. The rate constants for the
			phosphorylation of Ser(19) and Ser(40) were
			determined by electrospray ionization mass spectrometry
			using a consecutive reaction model. The
			rate constant for the phosphorylation of
			Ser(40) is approximately 2- to 3-fold higher
			if Ser(19) is already phosphorylated. These
			results suggest that phosphorylation of
			Ser(19) alters the conformation of tyrosine
			hydroxylase to allow increased accessibility
			of Ser(40) to kinases.

			DOI: 10.1074/jbc.M105280200 PMID: 11502746
			[Indexed for MEDLINE]

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