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). Forms homo- and heterooligomeric complexes. Binds Hep, a dual specificity protein kinase in the JNK pathway, but not its downstream target bsk. The C-terminal region interacts with the kinesin light chain protein, Klc, and the C-terminal PTY motif of amyloid-beta protein precursor-like protein, Appl. Expressed in the brain, CNS, PNS and cells posterior to the morphogenetic furrow in the eye imaginal disk of late embryos. Expressed from embryonic stage 12 through to adulthood. Belongs to the JIP scaffold family.