C-Jun-amino-terminal kinase-interacting protein 3 is a protein in humans that is encoded by MAPK8IP3 gene. The JNK-interacting protein (JIP) group of scaffold proteins selectively mediates JNK signaling by aggregating specific components of the MAPK cascade to form a functional JNK signaling module. May function as a regulator of vesicle transport, through interactions with the JNK-signaling components and motor proteins (By similarity).