TY - JOUR
T1 - Mutation of regulatory serines of rat tyrosine hydroxylase to glutamate
T2 - Effects on enzyme stability and activity
AU - Royo, Montserrat
AU - Fitzpatrick, Paul F.
AU - Daubner, S. Colette
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2005/2/15
Y1 - 2005/2/15
N2 - Tyrosine hydroxylase is phosphorylated at four serine residues in its amino-terminus by multiple kinases. Phosphorylation of serine 40 by cAMP-dependent protein kinase results in alleviation of dopamine inhibition [J. Biol. Chem. 267 (1992) 12639]. The other serines are at positions 8, 19, and 31. The effect of phosphorylation at these serines has been investigated using mutated forms of tyrosine hydroxylase containing glutamates at the positions of the serines. The S8E, S19E, and S31E tyrosine hydroxylase variants have similar steady-state kinetic parameters and similar binding affinity for catecholamines to wild-type enzyme. The S8E, S19E, S31E, and S40E variants differ in stability at elevated temperatures. The S40E variant is the least stable, while the others are all more stable than wild-type enzyme. The increased stability of S8E, S19E, and S31E tyrosine hydroxylases may be one of the physiological effects of phosphorylation. It may also have implications for the interpretation of activities of heterogeneous mixtures of tyrosine hydroxylase which have been phosphorylated.
AB - Tyrosine hydroxylase is phosphorylated at four serine residues in its amino-terminus by multiple kinases. Phosphorylation of serine 40 by cAMP-dependent protein kinase results in alleviation of dopamine inhibition [J. Biol. Chem. 267 (1992) 12639]. The other serines are at positions 8, 19, and 31. The effect of phosphorylation at these serines has been investigated using mutated forms of tyrosine hydroxylase containing glutamates at the positions of the serines. The S8E, S19E, and S31E tyrosine hydroxylase variants have similar steady-state kinetic parameters and similar binding affinity for catecholamines to wild-type enzyme. The S8E, S19E, S31E, and S40E variants differ in stability at elevated temperatures. The S40E variant is the least stable, while the others are all more stable than wild-type enzyme. The increased stability of S8E, S19E, and S31E tyrosine hydroxylases may be one of the physiological effects of phosphorylation. It may also have implications for the interpretation of activities of heterogeneous mixtures of tyrosine hydroxylase which have been phosphorylated.
KW - Dopamine
KW - Enzyme phosphorylation
KW - Enzyme regulation
KW - Enzyme stability
KW - Site-directed mutagenesis
KW - Tyrosine hydroxylase
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U2 - 10.1016/j.abb.2004.11.007
DO - 10.1016/j.abb.2004.11.007
M3 - Article
C2 - 15639226
AN - SCOPUS:11444260122
VL - 434
SP - 266
EP - 274
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 2
ER -