Са2+- та Са2+-кальмодулін-залежні протеїнкінази – потенційні регулятори структури і функцій мікротрубочок у рослин
Aim. Evaluate involvement of calcium/calmodulin-dependent protein kinases in regulation of plant microtubules using bioinformatic and structural biological methods. Methods. Sequences of tubulins isoforms was taken from UniProtKB. Profile prediction of phosphorylation sites was done using KinasePhos 2.0 service. Locating of potential phosphorylation sites was conducted on 3D-models of A. thaliana γ-tubulin complex and tubulin dimer, build using template X-ray RCSB Protein Data Bank structures; Modeller 9v8, I-Tasser, EasyModeller, HADDOCK, GROMACS 4.5.3, MolProbity, QMEAN software and visualized through PyMol 1.5 and UCSF Chimera 1.8. Results. It was predicted existence of potential phosphorylation sites matched profiles of calcium/calmodulin-dependent protein kinase 2 (CaMK2) in all Arabidopsis isotypes of β- and γ-tubulin: Ser32, Ser259, Ser321, Ser376 in both isotypes of γ-tubulin (TBG1 and TBG2), and Thr312 conserved in all β-tubulins (TBB1-TBB9). Conclusions. Considering location of specified amino acid residues, we assume that calcium/calmodulin-dependent protein kinases may be involved in regulation of plant microtubules. We assume that phosphorylation in these positions may have a significant impact on the microtubule dynamics, formation of α-/β-tubulin dimer and primary microtubule nucleation centers in plants.
Keywords: plant microtubules, tubulin, γTuSC complexes, phosphorylation, calcium/calmodulin-dependent protein kinases, protein kinase CaMK2, potential sites.