JNK-interacting protein 1 (JIP1, also known as IB1, MAPK8IP1 or C-Jun-amino-terminal kinase-interacting protein 1) is highly expressed in neurons where it functions as an adaptor linking motor to cargo during axonal transport []. It also affects microtubule dynamics in neurons. JIP1 is also found in pancreatic beta-cells where it is involved in regulating insulin secretion []. In addition to a JNK binding domain, JIP1 also contains SH3 and Phosphotyrosine-binding (PTB) domains. Its SH3 domain homodimerizes at the interface usually involved in proline-rich ligand recognition, despite the lack of this motif in the domain itself [].
