Cytoplasmic dynein-1 cargo diversity is mediated by the combinatorial assembly of FTS-Hook-FHIP complexes.

Jenna R Christensen,Agnieszka A Kendrick,Adriana Aguilar-Maldonado,Joey B Truong,Monika Dzieciatkowska,Samara L Reck-Peterson,Vinit Adani

doi:10.7554/elife.74538

Jenna R Christensen, Agnieszka A Kendrick + Show 5 more

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https://doi.org/10.7554/elife.74538

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Abstract

In eukaryotic cells, intracellular components are organized by the microtubule motors cytoplasmic dynein-1 (dynein) and kinesins, which are linked to cargos via adaptor proteins. While ~40 kinesins transport cargo toward the plus end of microtubules, a single dynein moves cargo in the opposite direction. How dynein transports a wide variety of cargos remains an open question. The FTS-Hook-FHIP ('FHF') cargo adaptor complex links dynein to cargo in humans and fungi. As human cells have three Hooks and four FHIP proteins, we hypothesized that the combinatorial assembly of different Hook and FHIP proteins could underlie dynein cargo diversity. Using proteomic approaches, we determine the protein 'interactome' of each FHIP protein. Live-cell imaging and biochemical approaches show that different FHF complexes associate with distinct motile cargos. These complexes also move with dynein and its cofactor dynactin in single-molecule in vitro reconstitution assays. Complexes composed of FTS, FHIP1B, and Hook1/Hook3 colocalize with Rab5-tagged early endosomes via a direct interaction between FHIP1B and GTP-bound Rab5. In contrast, complexes composed of FTS, FHIP2A, and Hook2 colocalize with Rab1A-tagged ER-to-Golgi cargos and FHIP2A is involved in the motility of Rab1A tubules. Our findings suggest that combinatorial assembly of different FTS-Hook-FHIP complexes is one mechanism dynein uses to achieve cargo specificity.

Highlights

Proper positioning of intracellular material in space and time is crucial for many cellular processes including cell division, cell signaling, and vesicle trafficking (Burute and Kapitein, 2019)
We found that FHIP1B colocalized with motile and non-motile 288 Rab5B early endosomes via live-cell imaging (Figure 5B-C, Video 3)
We found that FHIP2A colocalized with GMAP210, SCFD1, and BET1 (Figure 6 – figure supplement 1C), further confirming that FHIP2A is involved in endoplasmic reticulum (ER)-to-Golgi transport

Summary

Introduction

Proper positioning of intracellular material in space and time is crucial for many cellular processes including cell division, cell signaling, and vesicle trafficking (Burute and Kapitein, 2019). Kinesin and dynein are responsible for transporting many diverse cargos including membrane-bound organelles, mRNAs, and protein complexes (Hirokawa et al, 2009; Reck-Peterson et al, 2018). Processive dynein motility requires the dynactin complex and a coiled-coil activating adaptor (McKenney et al, 2014; Schlager et al, 2014a). There are ~20 known or candidate activating adaptors in human cells, several of which have been implicated in linking dynein to different cargos (Reck-Peterson et al., 2018; Wang et al, 2019). How activating adaptors link dynein to its cargo is only known in a few cases (Hoogenraad et al, 2001; Matanis et al, 2002; Schlager et al., 2010). Hook proteins make up one component of the “FHF” complex consisting of FTS/AKTIP (“FTS” here), Hook, and FHIP (FHF complex subunit Hook Interacting Protein) (Figure 1A)

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