title: SKIP controls lysosome positioning using a composite kinesin-1 heavy and light chain-binding domain.
abstract: The molecular interplay between cargo recognition and regulation of the activity of the kinesin-1 microtubule motor is not well understood. Using the lysosome adaptor SKIP (also known as PLEKHM2) as model cargo, we show that the kinesin heavy chains (KHCs), in addition to the kinesin light chains (KLCs), can recognize tryptophan-acidic-binding determinants on the cargo when presented in the context of an extended KHC-interacting domain. Mutational separation of KHC and KLC binding shows that both interactions are important for SKIP-kinesin-1 interactionin vitroand that KHC binding is important for lysosome transportin vivoHowever, in the absence of KLCs, SKIP can only bind to KHC when autoinhibition is relieved, suggesting that the KLCs gate access to the KHCs. We propose a model whereby tryptophan-acidic cargo is first recognized by KLCs, resulting in destabilization of KHC autoinhibition. This primary event then makes accessible a second SKIP-binding site on the KHC C-terminal tail that is adjacent to the autoinhibitory IAK region. Thus, cargo recognition and concurrent activation of kinesin-1 proceed in hierarchical stepwise fashion driven by a dynamic network of inter- and intra-molecular interactions.
authors.affiliation: Randall Division of Cell and Molecular Biophysics, King's College London, London, SE1 1UL, UK.
authors.forename: Anneri
authors.initials: A
authors.lastname: Sanger
authors.affiliation: Randall Division of Cell and Molecular Biophysics, King's College London, London, SE1 1UL, UK.
authors.forename: Yan Y
authors.initials: YY
authors.lastname: Yip
authors.affiliation: Randall Division of Cell and Molecular Biophysics, King's College London, London, SE1 1UL, UK.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Randall
authors.affiliation: Randall Division of Cell and Molecular Biophysics, King's College London, London, SE1 1UL, UK.
authors.forename: Stefano
authors.initials: S
authors.lastname: Pernigo
authors.affiliation: Randall Division of Cell and Molecular Biophysics, King's College London, London, SE1 1UL, UK.
authors.forename: Roberto A
authors.initials: RA
authors.lastname: Steiner
authors.affiliation: Randall Division of Cell and Molecular Biophysics, King's College London, London, SE1 1UL, UK mark.dodding@kcl.ac.uk.
authors.forename: Mark P
authors.identifier: 0000-0001-8091-6534
authors.initials: MP
authors.lastname: Dodding
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000378:metabolism*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002135:Calcium-Binding Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D016547:Kinesins / Q000378:metabolism*; D008247:Lysosomes / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D000072417:Protein Domains; D051381:Rats
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002135:Calcium-Binding Proteins; C488101:KIF5B protein, human; C000612996:KIF5C protein, rat; D016547:Kinesins
keywords: Kinesin-1; Lysosome positioning; Microtubule transport; SKIP