In vitro and in silico studies on substrate recognition and acceptance of human PKMYT1, a Cdk1 inhibitory kinase.

The human Myt1 kinase (PKMYT1) is an important regulator of the G2/M transition in the cell cycle. Presently, limited knowledge about its substrate recognition is available. Here, various potential substrates were investigated by different antibody based techniques including fluorescence polarization immunoassays and immunoblotting. Regarding both Thr and Tyr kinase activity, only protein substrates were found to be phosphorylated by Myt1, whereas any tested peptide was not recognized. In silico molecular dynamics studies were used to compare the stability of the Myt1 peptide complex with Wee1 peptide complex and support the biochemical findings. Furthermore, a Myt1 kinase binding assay suggests Myt1 being insensitive to staurosporine.