Human dihydrofolate reductase is a substrate of protein kinase CK2α
| Autor: | Elżbieta Senkara, Dominik Cysewski, Paweł Wilamowski, Joanna Cieśla, Monika Wielechowska, Maria Bretner, Patrycja Wińska, Katarzyna Skierka |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Biophysics Biochemistry Substrate Specificity Serine 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Catalytic Domain Dihydrofolate reductase Humans Protein phosphorylation Protein Interaction Maps Phosphorylation Threonine Casein Kinase II Protein kinase A Site-directed mutagenesis Molecular Biology biology Cell Biology Kinetics Tetrahydrofolate Dehydrogenase enzymes and coenzymes (carbohydrates) 030104 developmental biology chemistry 030220 oncology & carcinogenesis Phosphoserine biology.protein Protein Binding |
| Zdroj: | Biochemical and Biophysical Research Communications. 513:368-373 |
| ISSN: | 0006-291X |
| Popis: | Dihydrofolate reductase (DHFR) is a prominent molecular target in antitumor, antibacterial, antiprotozoan, and immunosuppressive chemotherapies, and CK2 protein kinase is an ubiquitous enzyme involved in many processes, such as tRNA and rRNA synthesis, apoptosis, cell cycle or oncogenic transformation. We show for the first time that CK2α subunit strongly interacted with and phosphorylated DHFR in vitro. Using quartz crystal microbalance with dissipation monitoring (QCM-D) we determined DHFR-CK2α binding kinetic parameters (Kd below 0.5 μM, kon = 10.31 × 104 M−1s−1 and koff = 1.40 × 10−3s−1) and calculated Gibbs free energy (−36.4 kJ/mol). In order to identify phosphorylation site(s) we used site-directed mutagenesis to obtain several DHFR mutants with predicted CK2-phosphorylable serine or threonine residues substituted with alanines. All enzyme forms were subjected to CK2α subunit catalytic activity and the results pointed to serine 168 as a phosphorylation site. Mass spectrometry analyses confirmed the presence of phosphoserine 168 and revealed additionally the presence of phosphoserine 145, although the latter phosphorylation was on a very low level. |
| Databáze: | OpenAIRE |
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