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.