The 14-3-3 protein affects the conformation of the regulatory domain of human tyrosine hydroxylase. Export

@article{citeulike:3787672, abstract = {Tyrosine hydroxylase (TH) catalyzes the first step in the biosynthesis of catecholamines. Regulation of TH enzyme activity is controlled through the posttranslational modification of its regulatory domain. The regulatory domain of TH can be phosphorylated at four serines (8, 19, 31, and 40) by a variety of protein kinases. Phosphorylation of Ser19 does not by itself increase TH activity but induces its binding to the 14-3-3 protein. That leads to the enhancement of TH activity with a still not fully understood mechanism. The main goal of this work was to investigate whether the 14-3-3 protein binding affects the conformation of the regulatory domain of human TH isoform 1 (TH1R). Site-directed mutagenesis was used to generate five single-tryptophan mutants of TH1R with the Trp residue located at five different positions within the domain (positions 14, 34, 73, 103, and 131). Time-resolved tryptophan fluorescence measurements revealed that phosphorylation of Ser19 and Ser40 does not itself induce any significant structural changes in regions surrounding inserted tryptophans. On the other hand, the interaction between the 14-3-3 protein and phosphorylated TH1R decreases the solvent exposure of tryptophan residues at positions 14 and 34 and induces distinct structural change in the vicinity of Trp73. The 14-3-3 protein binding also reduces the sensitivity of phosphorylated TH1R to proteolysis by protecting its N-terminal part (first 33 residues). Circular dichroism measurements showed that TH1R is an unstructured protein with a low content of secondary structure and that neither phosphorylation nor the 14-3-3 protein binding changes its secondary structure.}, author = {Obsilova, Veronika and Nedbalkova, Eliska and Silhan, Jan and Boura, Evzen and Herman, Petr and Vecer, Jaroslav and Sulc, Miroslav and Teisinger, Jan and Dyda, Fred and Obsil, Tomas}, citeulike-article-id = {3787672}, citeulike-linkout-0 = {http://dx.doi.org/10.1021/bi7019468}, citeulike-linkout-1 = {http://pubs.acs.org/doi/abs/10.1021/bi7019468}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/18181650}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=18181650}, day = {12}, doi = {10.1021/bi7019468}, issn = {0006-2960}, journal = {Biochemistry}, keywords = {14-3-3, conformational\_change, phosphorylation, th}, month = {February}, number = {6}, pages = {1768--1777}, posted-at = {2009-09-18 15:17:25}, priority = {0}, title = {The 14-3-3 protein affects the conformation of the regulatory domain of human tyrosine hydroxylase.}, url = {http://dx.doi.org/10.1021/bi7019468}, volume = {47}, year = {2008} }

TY - JOUR ID - citeulike:3787672 L3 - citeulike-article-id:3787672 N2 - Tyrosine hydroxylase (TH) catalyzes the first step in the biosynthesis of catecholamines. Regulation of TH enzyme activity is controlled through the posttranslational modification of its regulatory domain. The regulatory domain of TH can be phosphorylated at four serines (8, 19, 31, and 40) by a variety of protein kinases. Phosphorylation of Ser19 does not by itself increase TH activity but induces its binding to the 14-3-3 protein. That leads to the enhancement of TH activity with a still not fully understood mechanism. The main goal of this work was to investigate whether the 14-3-3 protein binding affects the conformation of the regulatory domain of human TH isoform 1 (TH1R). Site-directed mutagenesis was used to generate five single-tryptophan mutants of TH1R with the Trp residue located at five different positions within the domain (positions 14, 34, 73, 103, and 131). Time-resolved tryptophan fluorescence measurements revealed that phosphorylation of Ser19 and Ser40 does not itself induce any significant structural changes in regions surrounding inserted tryptophans. On the other hand, the interaction between the 14-3-3 protein and phosphorylated TH1R decreases the solvent exposure of tryptophan residues at positions 14 and 34 and induces distinct structural change in the vicinity of Trp73. The 14-3-3 protein binding also reduces the sensitivity of phosphorylated TH1R to proteolysis by protecting its N-terminal part (first 33 residues). Circular dichroism measurements showed that TH1R is an unstructured protein with a low content of secondary structure and that neither phosphorylation nor the 14-3-3 protein binding changes its secondary structure. IS - 6 JF - Biochemistry SN - 0006-2960 EP - 1777 TI - The 14-3-3 protein affects the conformation of the regulatory domain of human tyrosine hydroxylase. VL - 47 SP - 1768 KW - 14-3-3 KW - conformational_change KW - phosphorylation KW - th AU - Obsilova, Veronika AU - Nedbalkova, Eliska AU - Silhan, Jan AU - Boura, Evzen AU - Herman, Petr AU - Vecer, Jaroslav AU - Sulc, Miroslav AU - Teisinger, Jan AU - Dyda, Fred AU - Obsil, Tomas PY - 2008/02/12/ UR - http://dx.doi.org/10.1021/bi7019468 ER -