Dissection of Binding between a Phosphorylated Tyrosine Hydroxylase Peptide and 14-3-3 zeta: A Complex Story Elucidated by NMR

作者：Hritz Jozef; Byeon In Ja L; Krzysiak Troy; Martinez Aurora; Sklenar Vladimir; Gronenborn Angela M^*

来源：Biophysical Journal, 2014, 107(9): 2185-2194.

DOI：10.1016/j.bpj.2014.08.039

Human tyrosine hydroxylase activity is regulated by phosphorylation of its N-terminus and by an interaction with the modulator 14-3-3 proteins. We investigated the binding of singly or doubly phosphorylated and thiophosphorylated peptides, comprising the first 50 amino acids of human tyrosine hydroxylase, isoform 1 (hTH1), that contain the critical interaction domain, to 14-3-3 zeta, by P-31 NMR. Single phosphorylation at S19 generates a high affinity 14-3-3 zeta binding epitope, whereas singly S40-phosphorylated peptide interacts with 14-3-3 zeta one order-of-magnitude weaker than the S19-phosphorylated peptide. Analysis of the binding data revealed that the 14-3-3 zeta dimer and the S19-and S40-doubly phosphorylated peptide interact in multiple ways, with three major complexes formed: 1), a single peptide bound to a 14-3-3 zeta dimer via the S19 phosphate with the S40 phosphate occupying the other binding site; 2), a single peptide bound to a 14-3-3 zeta dimer via the S19 phosphorous with the S40 free in solution; or 3), a 14-3-3 zeta dimer with two peptides bound via the S19 phosphorous to each binding site. Our system and data provide information as to the possible mechanisms by which 14-3-3 zeta can engage binding partners that possess two phosphorylation sites on flexible tails. Whether these will be realized in any particular interacting pair will naturally depend on the details of each system.

• 出版日期2014-11-4