Structural characterization of the RH1-LZI tandem of JIP3/4 highlights RH1 domains as a cytoskeletal motor-binding motif

Abstract

JIP3 and JIP4 (JNK-interacting proteins 3 and 4) are adaptors for cargo recruitment by dynein/dynactin and kinesin1 motors. Both are dimers that are stabilised by two sections of leucine zipper coiled coils. The N-terminal Leucine Zipper I (LZI) belongs to a section that binds dynein-DLIC and kinesin1-KHC, whilst the medial Leucine Zipper II (LZII) binds dynactin-p150glued and kinesin1-KLC. Structural data is available for the LZII, but the LZI section is still uncharacterized. Here we characterize the N-terminal part of JIP3/4 which consists of an RH1 (RILP homology 1) domain followed by the LZI coiled coil using bioinformatical, biophysical and structural approaches. The RH1-LZI tandem of JIP3 associates as a high affinity homodimer exhibiting elongated alpha-helical fold. 3D homology modelling of the RH1-LZI tandem reveals that the kinesin1-KHC binding site mainly overlaps with the RH1 domain. A sequence comparison search indicates that only one other protein family has RH1 domains similar to those of JIP3/4, the RILP (Rab-interacting lysosomal protein) family which consists of adaptor proteins linking Rab GTPases to cytoskeletal motors. RILPL2 is recruited through its RH1 domain by the myosin 5a motor. Here, we showed that the RH1 domain of JIP3 also interacts with myosin 5 A in vitro, highlighting JIP3/4 as possible myosin 5a adaptors. Finally, we propose that JIP3/4 and RILP family members define a unique RH1/RH2-architecture adaptor superfamily linking cytoskeletal motors and Rab GTPases.

A tunable LIC1-adaptor interaction modulates dynein activity in a cargo-specific manner

“…Both structures consist of a central coiled-coil preceded by a helix that runs antiparallel to the coiled-coil. As its name indicates, RILPL2 is related to RILP, which together with JIP1-4 (JNK-interacting proteins 1-4) forms part of a subfamily of RH1 domain-containing proteins 22 that has been implicated in interactions with the C-terminal region of LIC1 17,23 , although these proteins are not confirmed dynein-dynactin adaptors 1 . The LIC1 helix binds near the middle of the BICD2 coiled-coil segment and is oriented diagonally with respect to the axis of the coiled-coil (Fig.…”

Sequential dynein effectors regulate axonal autophagosome motility in a maturation-dependent pathway

“…7). JIP3 interacts with both kinesin and dynein-dynactin (Cockburn et al, 2018; Cavalli et al, 2005; Vilela et al, 2019) and activates kinesin-dependent motility in vitro (Sun et al, 2011). JIP3 regulates axonal autophagosome transport in C. elegans (Hill et al, 2019), and our work demonstrates a similar role in vertebrates.…”

“…Jnk-interacting protein 3 (JIP3; Drosophila Sunday driver/SYD; C. elegans UNC-16) has mostly been studied in the context of endolysosomal transport, but was recently shown to facilitate the dynein-mediated transport of autophagosomes along the axon in C. elegans (Marchesin et al, 2015; Hill et al, 2019). Structurally unrelated to JIP1, JIP3 interacts with kinesin-1, dynein, and dynactin (Cavalli et al, 2005; Arimoto et al, 2011; Cockburn et al, 2018; Vilela et al, 2019), suggesting that JIP3 may also contribute to the regulation of autophagosomal motility in mammalian neurons.…”

JIP3 links lysosome transport to regulation of multiple components of the axonal cytoskeleton

“…Although the mechanism for JIP3 association with lysosomes has not been definitively established, JIP3 contains a modular series of protein-protein interaction domains that provide clues about how this might occur. In particular, JIP3 and JIP4 contain Rab-interacting lysosomal protein (RILP) homology 1 and 2 (RH1 and RH2) domains (Vilela et al, 2019). The RH1 domain of RILP interacts with motors (kinesin heavy chain and dynein light intermediate chain) while the RH2 domain of RILP acts as an effector of the endolysosomal small GTPase Rab7 (Johansson et al, 2007;Tan et al, 2011).…”