Characterization of the Dependence of Src:ND2 Binding on Phosphorylation and Intramolecular Src Interactions

The role of the nonreceptor tyrosine kinase Src in up-regulating NMDAR activity via phosphorylating the carboxyl-terminal domain of NMDAR is well-known. The interaction between the intrinsically disordered regions of Src and an anchoring protein, ND2, is known to be essential in this up-regulation. However, the molecular mechanism underlying this docking remains elusive. We have demonstrated that the Src:ND2 interaction is phosphorylation regulated, resulting in an enhancement from no detectable binding to sub-micromolar binding, especially with Thr37/Ser75 phosphorylated. Moreover, we have discovered that the presence of SH3 domain increases binding affinity significantly from sub-millimolar to sub-micromolar. These results indicate how electrostatic interactions and intramolecular Src interactions influence the Src:ND2 interaction. Our findings expand knowledge of the regulatory possibilities of disordered proteins in general, and will be valuable for the development of therapeutic agents that target the Src:ND2 complex to treat the patients suffering from chronic pain.M.Sc.2019-11-15 00:00:0