4. Conclusion
In this study, we addressed how phosphorylation in the accessory domain affects the accessibility of the NES to an exportin. To study the phenomenon computationally, all-atom MD simulations of the non-phosphorylated and phosphorylated yNap1 systems were performed, with specific address of how the NES is exposed on the protein surface. To evaluate the exposure quantitatively, the SASAs of the NESs of Nap1-nonP and Nap1-P were measured. Interestingly, the median of the SASA distribution of Nap1-P was larger than that of Nap1-nonP, suggesting that phosphorylation in the accessory domain exposes the NES to increase its accessibility to an exportin. In conclusion, the accessibility of the NES of yNap1 is modulated by dislocation of the accessory domain via phosphorylation. The present computational results shed light on the mediation of molecular recognition on protein surfaces via the phosphorylation of essential residues on other proteins.