The interaction of Kinesin-1 with its adaptor protein JIP1 can be regulated via proteins binding to the JIP1-PTB domain
1 Department of Molecular Biology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
2 Molecular Medicine and Informatics Doctoral Program, Yokohama City University Graduate School of Medicine,Yokohama 236-0004, Japan
3 Department of Supramolecular Biology, International Graduate School of Arts and Sciences, Yokohama City University, Yokohama 230-0045, Japan
4 Department of Biology, Wakayama Medical University School of Medicine, Wakayama 641-0011, Japan
BMC Cell Biology 2013, 14:12 doi:10.1186/1471-2121-14-12Published: 4 March 2013
The regulatory mechanisms of motor protein-dependent intracellular transport are still not fully understood. The kinesin-1-binding protein, JIP1, can function as an adaptor protein that links kinesin-1 and other JIP1-binding “cargo” proteins. However, it is unknown whether these “cargo” proteins influence the JIP1–kinesin-1 binding.
We show here that JIP1–kinesin-1 binding in Neuro2a cells was dependent on conserved amino acid residues in the JIP1-phosphotyrosine binding (PTB) domain, including F687. In addition, mutation of F687 severely affected the neurite tip localization of JIP1. Proteomic analysis revealed another kinesin-1 binding protein, JIP3, as a major JIP1 binding protein. The association between JIP1 and JIP3 was dependent on the F687 residue in JIP1, and this association induced the formation of a stable ternary complex with kinesin-1. On the other hand, the binding of JIP1 and JIP3 was independent of kinesin-1 binding. We also show that other PTB binding proteins can interrupt the formation of the ternary complex.
The formation of the JIP1–kinesin-1 complex depends on the protein binding-status of the JIP1 PTB domain. This may imply a regulatory mechanism of kinesin-1-dependent intracellular transport.