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Li L, Ran J. Regulation of ciliary homeostasis by intraflagellar transport-independent kinesins. Cell Death Dis 2024; 15:47. [PMID: 38218748 PMCID: PMC10787775 DOI: 10.1038/s41419-024-06428-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 12/20/2023] [Accepted: 01/02/2024] [Indexed: 01/15/2024]
Abstract
Cilia are highly conserved eukaryotic organelles that protrude from the cell surface and are involved in sensory perception, motility, and signaling. Their proper assembly and function rely on the bidirectional intraflagellar transport (IFT) system, which involves motor proteins, including antegrade kinesins and retrograde dynein. Although the role of IFT-mediated transport in cilia has been extensively studied, recent research has highlighted the contribution of IFT-independent kinesins in ciliary processes. The coordinated activities and interplay between IFT kinesins and IFT-independent kinesins are crucial for maintaining ciliary homeostasis. In this comprehensive review, we aim to delve into the specific contributions and mechanisms of action of the IFT-independent kinesins in cilia. By shedding light on their involvement, we hope to gain a more holistic perspective on ciliogenesis and ciliopathies.
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Affiliation(s)
- Lin Li
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, 250014, China
| | - Jie Ran
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, 250014, China.
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2
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Jiang X, Ogawa T, Yonezawa K, Shimizu N, Ichinose S, Uchihashi T, Nagaike W, Moriya T, Adachi N, Kawasaki M, Dohmae N, Senda T, Hirokawa N. The two-step cargo recognition mechanism of heterotrimeric kinesin. EMBO Rep 2023; 24:e56864. [PMID: 37575008 PMCID: PMC10626431 DOI: 10.15252/embr.202356864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 07/21/2023] [Accepted: 08/03/2023] [Indexed: 08/15/2023] Open
Abstract
Kinesin-driven intracellular transport is essential for various cell biological events and thus plays a crucial role in many pathological processes. However, little is known about the molecular basis of the specific and dynamic cargo-binding mechanism of kinesins. Here, an integrated structural analysis of the KIF3/KAP3 and KIF3/KAP3-APC complexes unveils the mechanism by which KIF3/KAP3 can dynamically grasp APC in a two-step manner, which suggests kinesin-cargo recognition dynamics composed of cargo loading, locking, and release. Our finding is the first demonstration of the two-step cargo recognition and stabilization mechanism of kinesins, which provides novel insights into the intracellular trafficking machinery.
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Affiliation(s)
- Xuguang Jiang
- Department of Cell Biology and Anatomy, Graduate School of MedicineThe University of TokyoTokyoJapan
- Tsinghua‐Peking Center for Life Sciences, School of Life SciencesTsinghua UniversityBeijingChina
| | - Tadayuki Ogawa
- Department of Cell Biology and Anatomy, Graduate School of MedicineThe University of TokyoTokyoJapan
- Research Center for Advanced Medical ScienceDokkyo Medical UniversityTochigiJapan
- Biomolecular Characterization UnitRIKEN Center for Sustainable Resource ScienceWakoJapan
| | - Kento Yonezawa
- Structural Biology Research Center, Photon FactoryInstitute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)TsukubaJapan
- Center for Digital Green‐InnovationNara Institute of Science and TechnologyNaraJapan
| | - Nobutaka Shimizu
- Structural Biology Research Center, Photon FactoryInstitute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)TsukubaJapan
| | - Sotaro Ichinose
- Department of Cell Biology and Anatomy, Graduate School of MedicineThe University of TokyoTokyoJapan
- Department of Anatomy, Graduate School of MedicineGunma UniversityGunmaJapan
| | - Takayuki Uchihashi
- Department of PhysicsNagoya UniversityNagoyaJapan
- Exploratory Research Center on Life and Living Systems (ExCELLS)National Institutes of Natural SciencesOkazakiJapan
| | | | - Toshio Moriya
- Structural Biology Research Center, Photon FactoryInstitute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)TsukubaJapan
| | - Naruhiko Adachi
- Structural Biology Research Center, Photon FactoryInstitute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)TsukubaJapan
| | - Masato Kawasaki
- Structural Biology Research Center, Photon FactoryInstitute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)TsukubaJapan
| | - Naoshi Dohmae
- Biomolecular Characterization UnitRIKEN Center for Sustainable Resource ScienceWakoJapan
| | - Toshiya Senda
- Structural Biology Research Center, Photon FactoryInstitute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)TsukubaJapan
| | - Nobutaka Hirokawa
- Department of Cell Biology and Anatomy, Graduate School of MedicineThe University of TokyoTokyoJapan
- Juntendo Advanced Research Institute for Health ScienceJuntendo UniversityTokyoJapan
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3
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Arora S, Rana M, Sachdev A, D’Souza JS. Appearing and disappearing acts of cilia. J Biosci 2023. [DOI: 10.1007/s12038-023-00326-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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4
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Arora S, Rana M, Sachdev A, D'Souza JS. Appearing and disappearing acts of cilia. J Biosci 2023; 48:8. [PMID: 36924208 PMCID: PMC10005925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
The past few decades have seen a rise in research on vertebrate cilia and ciliopathy, with interesting collaborations between basic and clinical scientists. This work includes studies on ciliary architecture, composition, evolution, and organelle generation and its biological role. The human body has cells that harbour any of the following four types of cilia: 9+0 motile, 9+0 immotile, 9+2 motile, and 9+2 immotile. Depending on the type, cilia play an important role in cell/fluid movement, mating, sensory perception, and development. Defects in cilia are associated with a wide range of human diseases afflicting the brain, heart, kidneys, respiratory tract, and reproductive system. These are commonly known as ciliopathies and affect millions of people worldwide. Due to their complex genetic etiology, diagnosis and therapy have remained elusive. Although model organisms like Chlamydomonas reinhardtii have been a useful source for ciliary research, reports of a fascinating and rewarding translation of this research into mammalian systems, especially humans, are seen. The current review peeks into one of the complex features of this organelle, namely its birth, the common denominators across the formation of both 9+0 and 9+2 ciliary types, the molecules involved in ciliogenesis, and the steps that go towards regulating their assembly and disassembly.
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Affiliation(s)
- Shashank Arora
- School of Biological Sciences, UM-DAE Centre for Excellence in Basic Sciences, Kalina Campus, Santacruz (E), Mumbai 400098, India
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5
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The physiological cargo adaptor of kinesin-2 functions as an evolutionary conserved lockpick. Proc Natl Acad Sci U S A 2022; 119:e2109378119. [PMID: 35947619 PMCID: PMC9388150 DOI: 10.1073/pnas.2109378119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Specific recognition of cellular cargo and efficient transport to its correct intracellular destination is an infrastructural challenge faced by most eukaryotic cells. This remarkable deed is accomplished by processive motor proteins that are subject to robust regulatory mechanisms. The first level of regulation entails the ability of the motor to suppress its own activity. This autoinhibition is eventually relieved by specific cargo binding. To better understand the role of the cargo during motor activation, we dissected the activation mechanism of the ciliary homodimeric kinesin-2 from Caenorhabditis elegans by its physiological cargo. In functional reconstitution assays, we identified two cargo adaptor proteins that together are necessary and sufficient to allosterically activate the autoinhibited motor. Surprisingly, the orthologous adaptor proteins from the unicellular green algae Chlamydomonas reinhardtii also fully activated the kinesin-2 from worm, even though C. reinhardtii itself lacks a homodimeric kinesin-2 motor. The latter suggested that a motor activation mechanism similar to the C. elegans model existed already well before metazoans evolved, and prompted us to scrutinize predicted homodimeric kinesin-2 orthologs in other evolutionarily distant eukaryotes. We show that the ciliate Tetrahymena thermophila not only possesses a homodimeric kinesin-2 but that it also shares the same allosteric activation mechanism that we delineated in the C. elegans model. Our results point to a much more fundamental role of homodimeric kinesin-2 in intraflagellar transport (IFT) than previously thought and warrant further scrutiny of distantly related organisms toward a comprehensive picture of the IFT process and its evolution.
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Direct imaging of intraflagellar-transport turnarounds reveals that motors detach, diffuse, and reattach to opposite-direction trains. Proc Natl Acad Sci U S A 2021; 118:2115089118. [PMID: 34732580 PMCID: PMC8609318 DOI: 10.1073/pnas.2115089118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2021] [Indexed: 12/16/2022] Open
Abstract
Primary cilia are important organelles that exist in almost all eukaryotic cells. Intraflagellar transport (IFT) is a motor-protein–driven bidirectional intracellular transport mechanism in cilia. Previous studies have shown that motors in Caenorhabditis elegans chemosensory cilia undergo rapid turnarounds to effectively work together in driving orderly IFT. The mechanism of motor turnarounds has, however, remained unclear. Here, using a combination of advanced fluorescence imaging and single-molecule analysis, we directly show that the individual turnarounds are due to motors switching between opposite-direction IFT trains. Furthermore, we show that switching events consist of motors detaching from a train, diffusing to another one followed by attachment. This directly demonstrates that motors switch trains by diffusion, which clarifies the mechanism of motor turnarounds. Intraflagellar transport (IFT), a bidirectional intracellular transport mechanism in cilia, relies on the cooperation of kinesin-2 and IFT-dynein motors. In Caenorhabditis elegans chemosensory cilia, motors undergo rapid turnarounds to effectively work together in driving IFT. Here, we push the envelope of fluorescence imaging to obtain insight into the underlying mechanism of motor turnarounds. We developed an alternating dual-color imaging system that allows simultaneous single-molecule imaging of kinesin-II turnarounds and ensemble imaging of IFT trains. This approach allowed direct visualization of motor detachment and reattachment during turnarounds and accordingly demonstrated that the turnarounds are actually single-motor switching between opposite-direction IFT trains rather than the behaviors of motors moving independently of IFT trains. We further improved the time resolution of single-motor imaging up to 30 ms to zoom into motor turnarounds, revealing diffusion during motor turnarounds, which unveils the mechanism of motor switching trains: detach–diffuse–attach. The subsequent single-molecule analysis of turnarounds unveiled location-dependent diffusion coefficients and diffusion times for both kinesin-2 and IFT-dynein motors. From correlating the diffusion times with IFT train frequencies, we estimated that kinesins tend to attach to the next train passing in the opposite direction. IFT-dynein, however, diffuses longer and lets one or two trains pass before attaching. This might be a direct consequence of the lower diffusion coefficient of the larger IFT-dynein. Our results provide important insights into how motors can cooperate to drive intracellular transport.
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7
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Lin C, Tang D, Gao X, Jiang H, Du C, Zhu J. Molecular characterization, dynamic transcription, and potential function of KIF3A/KIF3B during spermiogenesis in Opsariichthys bidens. Gene 2021; 798:145795. [PMID: 34175396 DOI: 10.1016/j.gene.2021.145795] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 06/03/2021] [Accepted: 06/22/2021] [Indexed: 10/21/2022]
Abstract
Spermiogenesis is the final phase of spermatogenesis, wherein the spermatids differentiate into mature spermatozoa via complex morphological transformation. In this process, kinesin plays an important role. Here, we observed the morphological transformation of spermatids and analyzed the characterization, dynamic transcription, and potential function of kinesin KIF3A/KIF3B during spermiogenesis in Chinese hook snout carp (Opsariichthys bidens). We found that the full-length cDNAs of O. bidens kif3a and kif3b were 2544 and 2806 bp in length comprising 119 bp and 259 bp 5' untranslated region (UTR), 313 bp and 222 bp 3' UTR, and 2112 bp and 2325 bp open reading frame encoding 703 and 774 amino acids, respectively. Ob-KIF3A/KIF3B proteins have three domains, namely N-terminal head, coiled-coil stalk, and C-terminal tail, and exhibit high similarity with homologous proteins in vertebrates and invertebrates. Ob-kif3a/kif3b mRNAs were ubiquitously expressed in all tissues examined, with the highest expression in the brain and stage-IV testis. Immunofluorescence results showed that Ob-KIF3A was co-localized with tubulin and the mitochondria. Particularly, in early spermatids, Ob-KIF3A, tubulin, and the mitochondrial signals were evenly distributed in the cytoplasm, whereas in middle spermatids, they were distributed around the nucleus. In the late stage, the signals were concentrated on one side of the nucleus, where the tail is formed, whereas in mature sperms, they were detected in the midpiece and flagellum. These results indicate that Ob-KIF3A/KIF3B may participate in nuclear reshaping, flagellum formation, and mitochondrial aggregation in the midpiece during spermiogenesis.
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Affiliation(s)
- Chenwen Lin
- Key Laboratory of Applied Marine Biotechnology by the Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China
| | - Daojun Tang
- Key Laboratory of Applied Marine Biotechnology by the Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China
| | - Xinming Gao
- Key Laboratory of Applied Marine Biotechnology by the Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China
| | - Huayu Jiang
- Key Laboratory of Applied Marine Biotechnology by the Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China
| | - Chen Du
- Key Laboratory of Applied Marine Biotechnology by the Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China
| | - Junquan Zhu
- Key Laboratory of Applied Marine Biotechnology by the Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China.
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8
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Webb S, Mukhopadhyay AG, Roberts AJ. Intraflagellar transport trains and motors: Insights from structure. Semin Cell Dev Biol 2020; 107:82-90. [PMID: 32684327 PMCID: PMC7561706 DOI: 10.1016/j.semcdb.2020.05.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 05/19/2020] [Accepted: 05/26/2020] [Indexed: 11/17/2022]
Abstract
Intraflagellar transport (IFT) sculpts the proteome of cilia and flagella; the antenna-like organelles found on the surface of virtually all human cell types. By delivering proteins to the growing ciliary tip, recycling turnover products, and selectively transporting signalling molecules, IFT has critical roles in cilia biogenesis, quality control, and signal transduction. IFT involves long polymeric arrays, termed IFT trains, which move to and from the ciliary tip under the power of the microtubule-based motor proteins kinesin-II and dynein-2. Recent top-down and bottom-up structural biology approaches are converging on the molecular architecture of the IFT train machinery. Here we review these studies, with a focus on how kinesin-II and dynein-2 assemble, attach to IFT trains, and undergo precise regulation to mediate bidirectional transport.
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Affiliation(s)
- Stephanie Webb
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London, United Kingdom
| | - Aakash G Mukhopadhyay
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London, United Kingdom
| | - Anthony J Roberts
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London, United Kingdom.
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Douglas RL, Haltiwanger BM, Albisetti A, Wu H, Jeng RL, Mancuso J, Cande WZ, Welch MD. Trypanosomes have divergent kinesin-2 proteins that function differentially in flagellum biosynthesis and cell viability. J Cell Sci 2020; 133:jcs129213. [PMID: 32503938 DOI: 10.1242/jcs.129213] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 05/27/2020] [Indexed: 12/13/2022] Open
Abstract
Trypanosoma brucei, the causative agent of African sleeping sickness, has a flagellum that is crucial for motility, pathogenicity, and viability. In most eukaryotes, the intraflagellar transport (IFT) machinery drives flagellum biogenesis, and anterograde IFT requires kinesin-2 motor proteins. In this study, we investigated the function of the two T. brucei kinesin-2 proteins, TbKin2a and TbKin2b, in bloodstream form trypanosomes. We found that, compared to kinesin-2 proteins across other phyla, TbKin2a and TbKin2b show greater variation in neck, stalk and tail domain sequences. Both kinesins contributed additively to flagellar lengthening. Silencing TbKin2a inhibited cell proliferation, cytokinesis and motility, whereas silencing TbKin2b did not. TbKin2a was localized on the flagellum and colocalized with IFT components near the basal body, consistent with it performing a role in IFT. TbKin2a was also detected on the flagellar attachment zone, a specialized structure that connects the flagellum to the cell body. Our results indicate that kinesin-2 proteins in trypanosomes play conserved roles in flagellar biosynthesis and exhibit a specialized localization, emphasizing the evolutionary flexibility of motor protein function in an organism with a large complement of kinesins.
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Affiliation(s)
- Robert L Douglas
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Brett M Haltiwanger
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Anna Albisetti
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Haiming Wu
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Robert L Jeng
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Joel Mancuso
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - W Zacheus Cande
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Matthew D Welch
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
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10
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Nakayama K, Katoh Y. Architecture of the IFT ciliary trafficking machinery and interplay between its components. Crit Rev Biochem Mol Biol 2020; 55:179-196. [PMID: 32456460 DOI: 10.1080/10409238.2020.1768206] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cilia and flagella serve as cellular antennae and propellers in various eukaryotic cells, and contain specific receptors and ion channels as well as components of axonemal microtubules and molecular motors to achieve their sensory and motile functions. Not only the bidirectional trafficking of specific proteins within cilia but also their selective entry and exit across the ciliary gate is mediated by the intraflagellar transport (IFT) machinery with the aid of motor proteins. The IFT-B complex, which is powered by the kinesin-2 motor, mediates anterograde protein trafficking from the base to the tip of cilia, whereas the IFT-A complex together with the dynein-2 complex mediates retrograde protein trafficking. The BBSome complex connects ciliary membrane proteins to the IFT machinery. Defects in any component of this trafficking machinery lead to abnormal ciliogenesis and ciliary functions, and results in a broad spectrum of disorders, collectively called the ciliopathies. In this review article, we provide an overview of the architectures of the components of the IFT machinery and their functional interplay in ciliary protein trafficking.
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Affiliation(s)
- Kazuhisa Nakayama
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Yohei Katoh
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
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11
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Sonar P, Youyen W, Cleetus A, Wisanpitayakorn P, Mousavi SI, Stepp WL, Hancock WO, Tüzel E, Ökten Z. Kinesin-2 from C. reinhardtii Is an Atypically Fast and Auto-inhibited Motor that Is Activated by Heterotrimerization for Intraflagellar Transport. Curr Biol 2020; 30:1160-1166.e5. [PMID: 32142698 DOI: 10.1016/j.cub.2020.01.046] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 12/04/2019] [Accepted: 01/14/2020] [Indexed: 11/17/2022]
Abstract
Construction and function of virtually all cilia require the universally conserved process of intraflagellar transport (IFT) [1, 2]. During the atypically fast IFT in the green alga C. reinhardtii, on average, 10 kinesin-2 motors "line up" in a tight assembly on the trains [3], provoking the question of how these motors coordinate their action to ensure smooth and fast transport along the flagellum without standing in each other's way. Here, we show that the heterodimeric FLA8/10 kinesin-2 alone is responsible for the atypically fast IFT in C. reinhardtii. Notably, in single-molecule studies, FLA8/10 moved at speeds matching those of in vivo IFT [4] but additionally displayed a slow velocity distribution, indicative of auto-inhibition. Addition of the KAP subunit to generate the heterotrimeric FLA8/10/KAP relieved this inhibition, thus providing a mechanistic rationale for heterotrimerization with the KAP subunit fully activating FLA8/10 for IFT in vivo. Finally, we linked fast FLA8/10 and slow KLP11/20 kinesin-2 from C. reinhardtii and C. elegans through a DNA tether to understand the molecular underpinnings of motor coordination during IFT in vivo. For motor pairs from both species, the co-transport velocities very nearly matched the single-molecule velocities, and both complexes spent roughly 80% of the time with only one of the two motors attached to the microtubule. Thus, irrespective of phylogeny and kinetic properties, kinesin-2 motors work mostly alone without sacrificing efficiency. Our findings thus offer a simple mechanism for how efficient IFT is achieved across diverse organisms despite being carried out by motors with different properties.
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Affiliation(s)
- Punam Sonar
- Physik Department E22, Technische Universität München, Garching 85748, Germany
| | - Wiphu Youyen
- Department of Physics, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA
| | - Augustine Cleetus
- Physik Department E22, Technische Universität München, Garching 85748, Germany
| | | | - Sayed I Mousavi
- Department of Physics, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA
| | - Willi L Stepp
- Physik Department E22, Technische Universität München, Garching 85748, Germany
| | - William O Hancock
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA 16802, USA
| | - Erkan Tüzel
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA 19122, USA
| | - Zeynep Ökten
- Physik Department E22, Technische Universität München, Garching 85748, Germany.
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12
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Kushwaha VS, Acar S, Miedema DM, Denisov DV, Schall P, Peterman EJG. The crowding dynamics of the motor protein kinesin-II. PLoS One 2020; 15:e0228930. [PMID: 32053680 PMCID: PMC7018031 DOI: 10.1371/journal.pone.0228930] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 01/26/2020] [Indexed: 12/02/2022] Open
Abstract
Intraflagellar transport (IFT) in C. elegans chemosensory cilia is an example of functional coordination and cooperation of two motor proteins with distinct motility properties operating together in large groups to transport cargoes: a fast and processive homodimeric kinesin-2, OSM-3, and a slow and less processive heterotrimeric kinesin-2, kinesin-II. To study the mechanism of the collective dynamics of kinesin-II of C. elegans cilia in an in vitro system, we used Total Internal Reflection Fluorescence microscopy to image the motility of truncated, heterodimeric kinesin-II constructs at high motor densities. Using an analysis technique based on correlation of the fluorescence intensities, we extracted quantitative motor parameters, such as motor density, velocity and average run length, from the image. Our experiments and analyses show that kinesin-II motility parameters are far less affected by (self) crowding than OSM-3. Our observations are supported by numerical calculations based on the TASEP-LK model (Totally Asymmetric Simple Exclusion Process-Langmuir Kinetics). From a comparison of data and modelling of OSM-3 and kinesin-II, a general picture emerges of the collective dynamics of the kinesin motors driving IFT in C. elegans chemosensory cilia and the way the motors deal with crowding.
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Affiliation(s)
- Vandana S. Kushwaha
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit, Amsterdam, Netherlands
| | - Seyda Acar
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit, Amsterdam, Netherlands
| | - Daniël M. Miedema
- Institute of Physics, University of Amsterdam, Amsterdam, Netherlands
- Laboratory for Experimental Oncology and Radiobiology (LEXOR), Center for Experimental Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, Netherlands
| | - Dmitry V. Denisov
- Institute of Physics, University of Amsterdam, Amsterdam, Netherlands
| | - Peter Schall
- Institute of Physics, University of Amsterdam, Amsterdam, Netherlands
| | - Erwin J. G. Peterman
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit, Amsterdam, Netherlands
- * E-mail:
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13
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Yang R, Bostick Z, Garbouchian A, Luisi J, Banker G, Bentley M. A novel strategy to visualize vesicle-bound kinesins reveals the diversity of kinesin-mediated transport. Traffic 2019; 20:851-866. [PMID: 31461551 PMCID: PMC7714429 DOI: 10.1111/tra.12692] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 08/26/2019] [Accepted: 08/26/2019] [Indexed: 01/04/2023]
Abstract
In mammals, 15 to 20 kinesins are thought to mediate vesicle transport. Little is known about the identity of vesicles moved by each kinesin or the functional significance of such diversity. To characterize the transport mediated by different kinesins, we developed a novel strategy to visualize vesicle-bound kinesins in living cells. We applied this method to cultured neurons and systematically determined the localization and transport parameters of vesicles labeled by different members of the Kinesin-1, -2, and -3 families. We observed vesicle labeling with nearly all kinesins. Only six kinesins bound vesicles that undergo long-range transport in neurons. Of these, three had an axonal bias (KIF5B, KIF5C and KIF13B), two were unbiased (KIF1A and KIF1Bβ), and one transported only in dendrites (KIF13A). Overall, the trafficking of vesicle-bound kinesins to axons or dendrites did not correspond to their motor domain preference, suggesting that on-vesicle regulation is crucial for kinesin targeting. Surprisingly, several kinesins were associated with populations of somatodendritic vesicles that underwent little long-range transport. This assay should be broadly applicable for investigating kinesin function in many cell types.
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Affiliation(s)
- Rui Yang
- The Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, Oregon
- Department of Biochemistry, Duke University, Durham, North Carolina
| | - Zoe Bostick
- Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy, New York
| | - Alex Garbouchian
- Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy, New York
| | - Julie Luisi
- The Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, Oregon
| | - Gary Banker
- The Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, Oregon
| | - Marvin Bentley
- Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy, New York
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14
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Abstract
Cells from all three domains of life on Earth utilize motile macromolecular devices that protrude from the cell surface to generate forces that allow them to swim through fluid media. Research carried out on archaea during the past decade or so has led to the recognition that, despite their common function, the motility devices of the three domains display fundamental differences in their properties and ancestry, reflecting a striking example of convergent evolution. Thus, the flagella of bacteria and the archaella of archaea employ rotary filaments that assemble from distinct subunits that do not share a common ancestor and generate torque using energy derived from distinct fuel sources, namely chemiosmotic ion gradients and FlaI motor-catalyzed ATP hydrolysis, respectively. The cilia of eukaryotes, however, assemble via kinesin-2-driven intraflagellar transport and utilize microtubules and ATP-hydrolyzing dynein motors to beat in a variety of waveforms via a sliding filament mechanism. Here, with reference to current structural and mechanistic information about these organelles, we briefly compare the evolutionary origins, assembly and tactic motility of archaella, flagella and cilia.
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Affiliation(s)
- Shahid Khan
- Molecular Biology Consortium, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Jonathan M Scholey
- Department of Molecular and Cell Biology, University of California @ Davis, CA 95616, USA.
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15
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Wachter S, Jung J, Shafiq S, Basquin J, Fort C, Bastin P, Lorentzen E. Binding of IFT22 to the intraflagellar transport complex is essential for flagellum assembly. EMBO J 2019; 38:embj.2018101251. [PMID: 30940671 DOI: 10.15252/embj.2018101251] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 02/28/2019] [Accepted: 03/04/2019] [Indexed: 01/08/2023] Open
Abstract
Intraflagellar transport (IFT) relies on motor proteins and the IFT complex to construct cilia and flagella. The IFT complex subunit IFT22/RabL5 has sequence similarity with small GTPases although the nucleotide specificity is unclear because of non-conserved G4/G5 motifs. We show that IFT22 specifically associates with G-nucleotides and present crystal structures of IFT22 in complex with GDP, GTP, and with IFT74/81. Our structural analysis unravels an unusual GTP/GDP-binding mode of IFT22 bypassing the classical G4 motif. The GTPase switch regions of IFT22 become ordered upon complex formation with IFT74/81 and mediate most of the IFT22-74/81 interactions. Structure-based mutagenesis reveals that association of IFT22 with the IFT complex is essential for flagellum construction in Trypanosoma brucei although IFT22 GTP-loading is not strictly required.
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Affiliation(s)
- Stefanie Wachter
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Jamin Jung
- Trypanosome Cell Biology Unit, Institut Pasteur & INSERM U1201, Paris, France
| | - Shahaan Shafiq
- Trypanosome Cell Biology Unit, Institut Pasteur & INSERM U1201, Paris, France
| | - Jerome Basquin
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Cécile Fort
- Trypanosome Cell Biology Unit, Institut Pasteur & INSERM U1201, Paris, France
| | - Philippe Bastin
- Trypanosome Cell Biology Unit, Institut Pasteur & INSERM U1201, Paris, France
| | - Esben Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
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16
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Kösling SK, Fansa EK, Maffini S, Wittinghofer A. Mechanism and dynamics of INPP5E transport into and inside the ciliary compartment. Biol Chem 2018; 399:277-292. [PMID: 29140789 DOI: 10.1515/hsz-2017-0226] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 11/03/2017] [Indexed: 11/15/2022]
Abstract
The inositol polyphosphate 5'-phosphatase E (INPP5E) localizes to cilia. We showed that the carrier protein phosphodiesterase 6 delta subunit (PDE6δ) mediates the sorting of farnesylated INPP5E into cilia due to high affinity binding and release by the ADP-ribosylation factor (Arf)-like protein Arl3·GTP. However, the dynamics of INPP5E transport into and inside the ciliary compartment are not fully understood. Here, we investigate the movement of INPP5E using live cell fluorescence microscopy and fluorescence recovery after photobleaching (FRAP) analysis. We show that PDE6δ and the dynein transport system are essential for ciliary sorting and entry of INPP5E. However, its innerciliary transport is regulated solely by the intraflagellar transport (IFT) system, independent from PDE6δ activity and INPP5E farnesylation. By contrast, movement of Arl3 into and within cilia occurs freely by diffusion and IFT-independently. The farnesylation defective INPP5E CaaX box mutant loses the exclusive ciliary localization. The accumulation of this mutant at centrioles after photobleaching suggests an affinity trap mechanism for ciliary entry, that in case of the wild type is overcome by the interaction with PDE6δ. Collectively, we postulate a three-step mechanism regulating ciliary localization of INPP5E, consisting of farnesylation- and PDE6δ-mediated targeting, INPP5E-PDE6δ complex diffusion into the cilium with transfer to the IFT system, and retention inside cilia.
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Affiliation(s)
- Stefanie Kristine Kösling
- Structural Biology Group, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, D-44227 Dortmund, Germany
| | - Eyad Kalawy Fansa
- Structural Biology Group, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, D-44227 Dortmund, Germany
| | - Stefano Maffini
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, D-44227 Dortmund, Germany
| | - Alfred Wittinghofer
- Structural Biology Group, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, D-44227 Dortmund, Germany
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17
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Louka P, Vasudevan KK, Guha M, Joachimiak E, Wloga D, Tomasi RFX, Baroud CN, Dupuis-Williams P, Galati DF, Pearson CG, Rice LM, Moresco JJ, Yates JR, Jiang YY, Lechtreck K, Dentler W, Gaertig J. Proteins that control the geometry of microtubules at the ends of cilia. J Cell Biol 2018; 217:4298-4313. [PMID: 30217954 PMCID: PMC6279374 DOI: 10.1083/jcb.201804141] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 07/25/2018] [Accepted: 08/31/2018] [Indexed: 11/22/2022] Open
Abstract
Louka et al. describe three conserved proteins that regulate the positions of microtubule ends near the tips of cilia. Mutations in two of these proteins cause a brain malformation, Joubert syndrome. Thus, microtubule ends in cilia may play a role in the pathology of Joubert syndrome. Cilia, essential motile and sensory organelles, have several compartments: the basal body, transition zone, and the middle and distal axoneme segments. The distal segment accommodates key functions, including cilium assembly and sensory activities. While the middle segment contains doublet microtubules (incomplete B-tubules fused to complete A-tubules), the distal segment contains only A-tubule extensions, and its existence requires coordination of microtubule length at the nanometer scale. We show that three conserved proteins, two of which are mutated in the ciliopathy Joubert syndrome, determine the geometry of the distal segment, by controlling the positions of specific microtubule ends. FAP256/CEP104 promotes A-tubule elongation. CHE-12/Crescerin and ARMC9 act as positive and negative regulators of B-tubule length, respectively. We show that defects in the distal segment dimensions are associated with motile and sensory deficiencies of cilia. Our observations suggest that abnormalities in distal segment organization cause a subset of Joubert syndrome cases.
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Affiliation(s)
- Panagiota Louka
- Department of Cellular Biology, University of Georgia, Athens, GA
| | | | - Mayukh Guha
- Department of Cellular Biology, University of Georgia, Athens, GA
| | - Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Dorota Wloga
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Raphaël F-X Tomasi
- Department of Mechanics, LadHyX, Ecole Polytechnique-Centre National de la Recherche Scientifique, Palaiseau, France
| | - Charles N Baroud
- Department of Mechanics, LadHyX, Ecole Polytechnique-Centre National de la Recherche Scientifique, Palaiseau, France
| | - Pascale Dupuis-Williams
- UMR-S1174 Institut National de la Santé et de la Recherche Médicale, Université Paris-Sud, Bat 443, Orsay, France.,École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris, Paris, France
| | - Domenico F Galati
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Chad G Pearson
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Luke M Rice
- Departments of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX
| | - James J Moresco
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA
| | - John R Yates
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA
| | - Yu-Yang Jiang
- Department of Cellular Biology, University of Georgia, Athens, GA
| | - Karl Lechtreck
- Department of Cellular Biology, University of Georgia, Athens, GA
| | - William Dentler
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS
| | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, GA
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18
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Roberts AJ. Emerging mechanisms of dynein transport in the cytoplasm versus the cilium. Biochem Soc Trans 2018; 46:967-982. [PMID: 30065109 PMCID: PMC6103457 DOI: 10.1042/bst20170568] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 06/13/2018] [Accepted: 06/18/2018] [Indexed: 02/08/2023]
Abstract
Two classes of dynein power long-distance cargo transport in different cellular contexts. Cytoplasmic dynein-1 is responsible for the majority of transport toward microtubule minus ends in the cell interior. Dynein-2, also known as intraflagellar transport dynein, moves cargoes along the axoneme of eukaryotic cilia and flagella. Both dyneins operate as large ATP-driven motor complexes, whose dysfunction is associated with a group of human disorders. But how similar are their mechanisms of action and regulation? To examine this question, this review focuses on recent advances in dynein-1 and -2 research, and probes to what extent the emerging principles of dynein-1 transport could apply to or differ from those of the less well-understood dynein-2 mechanoenzyme.
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Affiliation(s)
- Anthony J Roberts
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London, U.K.
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19
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Quinn SM, Howsmon DP, Hahn J, Gilbert SP. Kinesin-2 heterodimerization alters entry into a processive run along the microtubule but not stepping within the run. J Biol Chem 2018; 293:13389-13400. [PMID: 29991594 DOI: 10.1074/jbc.ra118.002767] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 07/06/2018] [Indexed: 11/06/2022] Open
Abstract
Heterodimeric KIF3AC and KIF3AB, two members of the mammalian kinesin-2 family, generate force for microtubule plus end-directed cargo transport. However, the advantage of heterodimeric kinesins over homodimeric ones is not well-understood. We showed previously that microtubule association for entry into a processive run was similar in rate for KIF3AC and KIF3AB at ∼7.0 μm-1 s-1 Yet, for engineered homodimers of KIF3AA and KIF3BB, this constant is significantly faster at 11 μm-1 s-1 and much slower for KIF3CC at 2.1 μm-1 s-1 These results led us to hypothesize that heterodimerization of KIF3A with KIF3C and KIF3A with KIF3B altered the intrinsic catalytic properties of each motor domain. Here, we tested this hypothesis by using presteady-state stopped-flow kinetics and mathematical modeling. Surprisingly, the modeling revealed that the catalytic properties of KIF3A and KIF3B/C were altered upon microtubule binding, yet each motor domain retained its relative intrinsic kinetics for ADP release and subsequent ATP binding and the nucleotide-promoted transitions thereafter. These results are consistent with the interpretation that for KIF3AB, each motor head is catalytically similar and therefore each step is approximately equivalent. In contrast, for KIF3AC the results predict that the processive steps will alternate between a fast step for KIF3A followed by a slow step for KIF3C resulting in asymmetric stepping during a processive run. This study reveals the impact of heterodimerization of the motor polypeptides for microtubule association to start the processive run and the fundamental differences in the motile properties of KIF3C compared with KIF3A and KIF3B.
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Affiliation(s)
| | | | - Juergen Hahn
- Chemical and Biological Engineering, and .,Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180
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20
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Morthorst SK, Christensen ST, Pedersen LB. Regulation of ciliary membrane protein trafficking and signalling by kinesin motor proteins. FEBS J 2018; 285:4535-4564. [PMID: 29894023 DOI: 10.1111/febs.14583] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/09/2018] [Accepted: 06/11/2018] [Indexed: 12/14/2022]
Abstract
Primary cilia are antenna-like sensory organelles that regulate a substantial number of cellular signalling pathways in vertebrates, both during embryonic development as well as in adulthood, and mutations in genes coding for ciliary proteins are causative of an expanding group of pleiotropic diseases known as ciliopathies. Cilia consist of a microtubule-based axoneme core, which is subtended by a basal body and covered by a bilayer lipid membrane of unique protein and lipid composition. Cilia are dynamic organelles, and the ability of cells to regulate ciliary protein and lipid content in response to specific cellular and environmental cues is crucial for balancing ciliary signalling output. Here we discuss mechanisms involved in regulation of ciliary membrane protein trafficking and signalling, with main focus on kinesin-2 and kinesin-3 family members.
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21
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Gilbert SP, Guzik-Lendrum S, Rayment I. Kinesin-2 motors: Kinetics and biophysics. J Biol Chem 2018; 293:4510-4518. [PMID: 29444824 DOI: 10.1074/jbc.r117.001324] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Kinesin-2s are major transporters of cellular cargoes. This subfamily contains both homodimeric kinesins whose catalytic domains result from the same gene product and heterodimeric kinesins with motor domains derived from two different gene products. In this Minireview, we focus on the progress to define the biochemical and biophysical properties of the kinesin-2 family members. Our understanding of their mechanochemical capabilities has been advanced by the ability to identify the kinesin-2 genes in multiple species, expression and purification of these motors for single-molecule and ensemble assays, and development of new technologies enabling quantitative measurements of kinesin activity with greater sensitivity.
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Affiliation(s)
- Susan P Gilbert
- From the Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180 and
| | - Stephanie Guzik-Lendrum
- From the Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180 and
| | - Ivan Rayment
- the Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
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22
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Stepp WL, Merck G, Mueller-Planitz F, Ökten Z. Kinesin-2 motors adapt their stepping behavior for processive transport on axonemes and microtubules. EMBO Rep 2017; 18:1947-1956. [PMID: 28887322 DOI: 10.15252/embr.201744097] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 08/11/2017] [Accepted: 08/14/2017] [Indexed: 11/09/2022] Open
Abstract
Two structurally distinct filamentous tracks, namely singlet microtubules in the cytoplasm and axonemes in the cilium, serve as railroads for long-range transport processes in vivo In all organisms studied so far, the kinesin-2 family is essential for long-range transport on axonemes. Intriguingly, in higher eukaryotes, kinesin-2 has been adapted to work on microtubules in the cytoplasm as well. Here, we show that heterodimeric kinesin-2 motors distinguish between axonemes and microtubules. Unlike canonical kinesin-1, kinesin-2 takes directional, off-axis steps on microtubules, but it resumes a straight path when walking on the axonemes. The inherent ability of kinesin-2 to side-track on the microtubule lattice restricts the motor to one side of the doublet microtubule in axonemes. The mechanistic features revealed here provide a molecular explanation for the previously observed partitioning of oppositely moving intraflagellar transport trains to the A- and B-tubules of the same doublet microtubule. Our results offer first mechanistic insights into why nature may have co-evolved the heterodimeric kinesin-2 with the ciliary machinery to work on the specialized axonemal surface for two-way traffic.
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Affiliation(s)
- Willi L Stepp
- Physik Department E22, Technische Universität München, Garching, Germany
| | - Georg Merck
- Physik Department E22, Technische Universität München, Garching, Germany
| | - Felix Mueller-Planitz
- Molecular Biology, Biomedical Center, Faculty of Medicine, LMU Munich, Martinsried, Germany
| | - Zeynep Ökten
- Physik Department E22, Technische Universität München, Garching, Germany .,Munich Center for Integrated Protein Science, Munich, Germany
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23
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Prevo B, Scholey JM, Peterman EJG. Intraflagellar transport: mechanisms of motor action, cooperation, and cargo delivery. FEBS J 2017; 284:2905-2931. [PMID: 28342295 PMCID: PMC5603355 DOI: 10.1111/febs.14068] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 02/20/2017] [Accepted: 03/23/2017] [Indexed: 02/06/2023]
Abstract
Intraflagellar transport (IFT) is a form of motor-dependent cargo transport that is essential for the assembly, maintenance, and length control of cilia, which play critical roles in motility, sensory reception, and signal transduction in virtually all eukaryotic cells. During IFT, anterograde kinesin-2 and retrograde IFT dynein motors drive the bidirectional transport of IFT trains that deliver cargo, for example, axoneme precursors such as tubulins as well as molecules of the signal transduction machinery, to their site of assembly within the cilium. Following its discovery in Chlamydomonas, IFT has emerged as a powerful model system for studying general principles of motor-dependent cargo transport and we now appreciate the diversity that exists in the mechanism of IFT within cilia of different cell types. The absence of heterotrimeric kinesin-2 function, for example, causes a complete loss of both IFT and cilia in Chlamydomonas, but following its loss in Caenorhabditis elegans, where its primary function is loading the IFT machinery into cilia, homodimeric kinesin-2-driven IFT persists and assembles a full-length cilium. Generally, heterotrimeric kinesin-2 and IFT dynein motors are thought to play widespread roles as core IFT motors, whereas homodimeric kinesin-2 motors are accessory motors that mediate different functions in a broad range of cilia, in some cases contributing to axoneme assembly or the delivery of signaling molecules but in many other cases their ciliary functions, if any, remain unknown. In this review, we focus on mechanisms of motor action, motor cooperation, and motor-dependent cargo delivery during IFT.
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Affiliation(s)
- Bram Prevo
- Department of Cellular & Molecular Medicine, University of California San Diego, CA, USA
- Ludwig Institute for Cancer Research, San Diego, CA, USA
| | - Jonathan M Scholey
- Department of Molecular & Cell Biology, University of California Davis, CA, USA
| | - Erwin J G Peterman
- Department of Physics and Astronomy and LaserLaB Amsterdam, Vrije Universiteit, Amsterdam, The Netherlands
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24
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Intraflagellar transport velocity is governed by the number of active KIF17 and KIF3AB motors and their motility properties under load. Proc Natl Acad Sci U S A 2017; 114:E6830-E6838. [PMID: 28761002 DOI: 10.1073/pnas.1708157114] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Homodimeric KIF17 and heterotrimeric KIF3AB are processive, kinesin-2 family motors that act jointly to carry out anterograde intraflagellar transport (IFT), ferrying cargo along microtubules (MTs) toward the tips of cilia. How IFT trains attain speeds that exceed the unloaded rate of the slower, KIF3AB motor remains unknown. By characterizing the motility properties of kinesin-2 motors as a function of load we find that the increase in KIF3AB velocity, elicited by forward loads from KIF17 motors, cannot alone account for the speed of IFT trains in vivo. Instead, higher IFT velocities arise from an increased likelihood that KIF3AB motors dissociate from the MT, resulting in transport by KIF17 motors alone, unencumbered by opposition from KIF3AB. The rate of transport is therefore set by an equilibrium between a faster state, where only KIF17 motors move the train, and a slower state, where at least one KIF3AB motor on the train remains active in transport. The more frequently the faster state is accessed, the higher the overall velocity of the IFT train. We conclude that IFT velocity is governed by (i) the absolute numbers of each motor type on a given train, (ii) how prone KIF3AB is to dissociation from MTs relative to KIF17, and (iii) how prone both motors are to dissociation relative to binding MTs.
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25
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Affiliation(s)
- Gaia Pigino
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Stephen M King
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, Connecticut, USA
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26
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Ishikawa H, Marshall WF. Intraflagellar Transport and Ciliary Dynamics. Cold Spring Harb Perspect Biol 2017; 9:9/3/a021998. [PMID: 28249960 DOI: 10.1101/cshperspect.a021998] [Citation(s) in RCA: 126] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Cilia and flagella are microtubule-based organelles whose assembly requires a motile process, known as intraflagellar transport (IFT), to bring tubulin and other components to the distal tip of the growing structure. The IFT system uses a multiprotein complex with components that appear to be specialized for the transport of different sets of cargo proteins. The mechanisms by which cargo is selected for ciliary import and transport by IFT remain an area of active research. The complex dynamics of cilia and flagella are under constant regulation to ensure proper length control, and this regulation appears to involve regulation at the stage of IFT injection into the flagellum, as well as regulation of flagellar disassembly and, possibly, of cargo binding. Cilia and flagella thus represent a convenient model system to study how multiple motile and signaling pathways cooperate to control the assembly and dynamics of a complex cellular structure.
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Affiliation(s)
- Hiroaki Ishikawa
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, California 94158
| | - Wallace F Marshall
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, California 94158
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27
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Scholey JM, Civelekoglu-Scholey G, Brust-Mascher I. Anaphase B. BIOLOGY 2016; 5:biology5040051. [PMID: 27941648 PMCID: PMC5192431 DOI: 10.3390/biology5040051] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 11/30/2016] [Accepted: 12/01/2016] [Indexed: 11/16/2022]
Abstract
Anaphase B spindle elongation is characterized by the sliding apart of overlapping antiparallel interpolar (ip) microtubules (MTs) as the two opposite spindle poles separate, pulling along disjoined sister chromatids, thereby contributing to chromosome segregation and the propagation of all cellular life. The major biochemical “modules” that cooperate to mediate pole–pole separation include: (i) midzone pushing or (ii) braking by MT crosslinkers, such as kinesin-5 motors, which facilitate or restrict the outward sliding of antiparallel interpolar MTs (ipMTs); (iii) cortical pulling by disassembling astral MTs (aMTs) and/or dynein motors that pull aMTs outwards; (iv) ipMT plus end dynamics, notably net polymerization; and (v) ipMT minus end depolymerization manifest as poleward flux. The differential combination of these modules in different cell types produces diversity in the anaphase B mechanism. Combinations of antagonist modules can create a force balance that maintains the dynamic pre-anaphase B spindle at constant length. Tipping such a force balance at anaphase B onset can initiate and control the rate of spindle elongation. The activities of the basic motor filament components of the anaphase B machinery are controlled by a network of non-motor MT-associated proteins (MAPs), for example the key MT cross-linker, Ase1p/PRC1, and various cell-cycle kinases, phosphatases, and proteases. This review focuses on the molecular mechanisms of anaphase B spindle elongation in eukaryotic cells and briefly mentions bacterial DNA segregation systems that operate by spindle elongation.
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Affiliation(s)
- Jonathan M Scholey
- Department of Molecular and Cell Biology, University of California, Davis, CA 95616, USA.
| | | | - Ingrid Brust-Mascher
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
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28
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Srivastava S, Grace PS, Ernst JD. Antigen Export Reduces Antigen Presentation and Limits T Cell Control of M. tuberculosis. Cell Host Microbe 2016; 19:44-54. [PMID: 26764596 DOI: 10.1016/j.chom.2015.12.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Revised: 10/04/2015] [Accepted: 12/15/2015] [Indexed: 12/16/2022]
Abstract
Persistence of Mycobacterium tuberculosis results from bacterial strategies that manipulate host adaptive immune responses. Infected dendritic cells (DCs) transport M. tuberculosis to local lymph nodes but activate CD4 T cells poorly, suggesting bacterial manipulation of antigen presentation. However, M. tuberculosis antigens are also exported from infected DCs and taken up and presented by uninfected DCs, possibly overcoming this blockade of antigen presentation by infected cells. Here we show that the first stage of this antigen transfer, antigen export, benefits M. tuberculosis by diverting bacterial proteins from the antigen presentation pathway. Kinesin-2 is required for antigen export and depletion of this microtubule-based motor increases activation of antigen-specific CD4 T cells by infected cells and improves control of intracellular infection. Thus, although antigen transfer enables presentation by bystander cells, it does not compensate for reduced antigen presentation by infected cells and represents a bacterial strategy for CD4 T cell evasion.
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Affiliation(s)
- Smita Srivastava
- Division of Infectious Diseases and Immunology, Department of Medicine, New York University School of Medicine, New York, NY 10016, USA; Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
| | - Patricia S Grace
- Division of Infectious Diseases and Immunology, Department of Medicine, New York University School of Medicine, New York, NY 10016, USA; Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Joel D Ernst
- Division of Infectious Diseases and Immunology, Department of Medicine, New York University School of Medicine, New York, NY 10016, USA; Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA; Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
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29
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Taschner M, Lorentzen E. The Intraflagellar Transport Machinery. Cold Spring Harb Perspect Biol 2016; 8:cshperspect.a028092. [PMID: 27352625 DOI: 10.1101/cshperspect.a028092] [Citation(s) in RCA: 237] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Eukaryotic cilia and flagella are evolutionarily conserved organelles that protrude from the cell surface. The unique location and properties of cilia allow them to function in vital processes such as motility and signaling. Ciliary assembly and maintenance rely on intraflagellar transport (IFT), the bidirectional movement of a multicomponent transport system between the ciliary base and tip. Since its initial discovery more than two decades ago, considerable effort has been invested in dissecting the molecular mechanisms of IFT in a variety of model organisms. Importantly, IFT was shown to be essential for mammalian development, and defects in this process cause a number of human pathologies known as ciliopathies. Here, we review current knowledge of IFT with a particular emphasis on the IFT machinery and specific mechanisms of ciliary cargo recognition and transport.
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Affiliation(s)
- Michael Taschner
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, D-82152 Martinsried, Germany
| | - Esben Lorentzen
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, D-82152 Martinsried, Germany
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30
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Albracht CD, Guzik-Lendrum S, Rayment I, Gilbert SP. Heterodimerization of Kinesin-2 KIF3AB Modulates Entry into the Processive Run. J Biol Chem 2016; 291:23248-23256. [PMID: 27637334 DOI: 10.1074/jbc.m116.752196] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Indexed: 11/06/2022] Open
Abstract
Mammalian KIF3AB is an N-terminal processive kinesin-2 that is best known for its roles in intracellular transport. There has been significant interest in KIF3AB to define the key principles that underlie its processivity but also to define the mechanistic basis of its sensitivity to force. In this study, the kinetics for entry into the processive run were quantified. The results show for KIF3AB that the kinetics of microtubule association at 7 μm-1 s-1 is less than the rates observed for KIF3AA at 13 μm-1 s-1 or KIF3BB at 11.9 μm-1 s-1 ADP release after microtubule association for KIF3AB is 33 s-1 and is significantly slower than ADP release from homodimeric KIF3AA and KIF3BB, which reach 80-90 s-1 To explore the interhead communication implied by the rate differences at these first steps, we compared the kinetics of KIF3AB microtubule association followed by ADP release with the kinetics for mixtures of KIF3AA plus KIF3BB. Surprisingly, the kinetics of KIF3AB are not equivalent to any of the mixtures of KIF3AA + KIF3BB. In fact, the transients for each of the mixtures overlay the transients for KIF3AA and KIF3BB. These results reveal that intermolecular communication within the KIF3AB heterodimer modulates entry into the processive run, and the results suggest that it is the high rate of microtubule association that drives rebinding to the microtubule after force-dependent motor detachment.
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Affiliation(s)
- Clayton D Albracht
- From the Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180 and
| | - Stephanie Guzik-Lendrum
- From the Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180 and
| | - Ivan Rayment
- the Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Susan P Gilbert
- From the Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180 and
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31
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Cyrus BF, Muller WA. A Unique Role for Endothelial Cell Kinesin Light Chain 1, Variant 1 in Leukocyte Transendothelial Migration. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:1375-86. [PMID: 26994343 PMCID: PMC4861765 DOI: 10.1016/j.ajpath.2016.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 12/19/2015] [Accepted: 01/07/2016] [Indexed: 01/05/2023]
Abstract
A reservoir of parajunctional membrane in endothelial cells, the lateral border recycling compartment (LBRC), is critical for transendothelial migration (TEM). We have previously shown that targeted recycling of the LBRC to the site of TEM requires microtubules and a kinesin molecular motor. However, the identity of the kinesin and mechanism of cargo binding were not known. We show that microinjection of endothelial cells with a monoclonal antibody specific for kinesin-1 significantly blocked LBRC-targeted recycling and TEM. In complementary experiments, knocking down KIF5B, a ubiquitous kinesin-1 isoform, in endothelial cells significantly decreased targeted recycling of the LBRC and leukocyte TEM. Kinesin heavy chains move cargo along microtubules by one of many kinesin light chains (KLCs), which directly bind the cargo. Knocking down KLC 1 isoform variant 1 (KLC1C) significantly decreased LBRC-targeted recycling and TEM, whereas knocking down other isoforms of KLC1 had no effect. Re-expression of KLC1C resistant to the knockdown shRNA restored targeted recycling and TEM. Thus kinesin-1 and KLC1C are specifically required for targeted recycling and TEM. These data suggest that of the many potential combinations of the 45 kinesin family members and multiple associated light chains, KLC1C links the LBRC to kinesin-1 (KIF5B) during targeted recycling and TEM. Thus, KLC1C can potentially be used as a target for anti-inflammatory therapy.
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Affiliation(s)
- Bita F Cyrus
- Department of Pathology, The Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - William A Muller
- Department of Pathology, The Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
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32
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Zhang P, Rayment I, Gilbert SP. Fast or Slow, Either Head Can Start the Processive Run of Kinesin-2 KIF3AC. J Biol Chem 2015; 291:4407-16. [PMID: 26710851 DOI: 10.1074/jbc.m115.705970] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Indexed: 11/06/2022] Open
Abstract
Mammalian KIF3AC contains two distinct motor polypeptides and is best known for its role in organelle transport in neurons. Our recent studies showed that KIF3AC is as processive as conventional kinesin-1, suggesting that their ATPase mechanochemistry may be similar. However, the presence of two different motor polypeptides in KIF3AC implies that there must be a cellular advantage for the KIF3AC heterodimer. The hypothesis tested was whether there is an intrinsic bias within KIF3AC such that either KIF3A or KIF3C initiates the processive run. To pursue these experiments, a mechanistic approach was used to compare the pre-steady-state kinetics of KIF3AC to the kinetics of homodimeric KIF3AA and KIF3CC. The results indicate that microtubule collision at 11.4 μM(-1) s(-1) coupled with ADP release at 78 s(-1) are fast steps for homodimeric KIF3AA. In contrast, KIF3CC exhibits much slower microtubule association at 2.1 μM(-1) s(-1) and ADP release at 8 s(-1). For KIF3AC, microtubule association at 6.6 μM(-1) s(-1) and ADP release at 51 s(-1) are intermediate between the constants for KIF3AA and KIF3CC. These results indicate that either KIF3A or KIF3C can initiate the processive run. Surprisingly, the kinetics of the initial event of microtubule collision followed by ADP release for KIF3AC is not equivalent to 1:1 mixtures of KIF3AA plus KIF3CC homodimers at the same motor concentration. These results reveal that the intermolecular communication within the KIF3AC heterodimer modulates entry into the processive run regardless of whether the run is initiated by the KIF3A or KIF3C motor domain.
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Affiliation(s)
- Pengwei Zhang
- From the Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180 and
| | - Ivan Rayment
- the Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Susan P Gilbert
- From the Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180 and
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Prevo B, Mangeol P, Oswald F, Scholey JM, Peterman EJG. Functional differentiation of cooperating kinesin-2 motors orchestrates cargo import and transport in C. elegans cilia. Nat Cell Biol 2015; 17:1536-45. [PMID: 26523365 DOI: 10.1038/ncb3263] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 09/30/2015] [Indexed: 12/19/2022]
Abstract
Intracellular transport depends on cooperation between distinct motor proteins. Two anterograde intraflagellar transport (IFT) motors, heterotrimeric kinesin-II and homodimeric OSM-3, cooperate to move cargo along Caenorhabditis elegans cilia. Here, using quantitative fluorescence microscopy, with single-molecule sensitivity, of IFT in living strains containing single-copy transgenes encoding fluorescent IFT proteins, we show that kinesin-II transports IFT trains through the ciliary base and transition zone to a 'handover zone' on the proximal axoneme. There, OSM-3 gradually replaces kinesin-II, yielding velocity profiles inconsistent with in vitro motility assays, and then drives transport to the ciliary tip. Dissociated kinesin-II motors undergo rapid turnaround and recycling to the ciliary base, whereas OSM-3 is recycled mainly to the handover zone. This reveals a functional differentiation in which the slower, less processive kinesin-II imports IFT trains into the cilium and OSM-3 drives their long-range transport, thereby optimizing cargo delivery.
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Affiliation(s)
- Bram Prevo
- Department of Physics and Astronomy and LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081 1081 HV Amsterdam, The Netherlands
| | - Pierre Mangeol
- Department of Physics and Astronomy and LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081 1081 HV Amsterdam, The Netherlands
| | - Felix Oswald
- Department of Physics and Astronomy and LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081 1081 HV Amsterdam, The Netherlands
| | - Jonathan M Scholey
- Department of Molecular and Cellular Biology, University of California at Davis, Davis, California 95616, USA
| | - Erwin J G Peterman
- Department of Physics and Astronomy and LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081 1081 HV Amsterdam, The Netherlands
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Jiang L, Wei Y, Ronquillo CC, Marc RE, Yoder BK, Frederick JM, Baehr W. Heterotrimeric kinesin-2 (KIF3) mediates transition zone and axoneme formation of mouse photoreceptors. J Biol Chem 2015; 290:12765-78. [PMID: 25825494 DOI: 10.1074/jbc.m115.638437] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Indexed: 11/06/2022] Open
Abstract
Anterograde intraflagellar transport (IFT) employing kinesin-2 molecular motors has been implicated in trafficking of photoreceptor outer segment proteins. We generated embryonic retina-specific (prefix "emb") and adult tamoxifen-induced (prefix "tam") deletions of KIF3a and IFT88 in adult mice to study photoreceptor ciliogenesis and protein trafficking. In (emb)Kif3a(-/-) and in (emb)Ift88(-/-) mice, basal bodies failed to extend transition zones (connecting cilia) with outer segments, and visual pigments mistrafficked. In contrast, (tam)Kif3a(-/-) and (tam)Ift88(-/-) photoreceptor axonemes disintegrated slowly post-induction, starting distally, but rhodopsin and cone pigments trafficked normally for more than 2 weeks, a time interval during which the outer segment is completely renewed. The results demonstrate that visual pigments transport to the retinal outer segment despite removal of KIF3 and IFT88, and KIF3-mediated anterograde IFT is responsible for photoreceptor transition zone and axoneme formation.
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Affiliation(s)
- Li Jiang
- From the Departments of Ophthalmology and Visual Sciences and
| | - Yuxiao Wei
- From the Departments of Ophthalmology and Visual Sciences and
| | | | - Robert E Marc
- From the Departments of Ophthalmology and Visual Sciences and
| | - Bradley K Yoder
- the Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, and
| | | | - Wolfgang Baehr
- From the Departments of Ophthalmology and Visual Sciences and the Department of Biology, University of Utah, Salt Lake City, Utah 84112 Neurobiology and Anatomy, University of Utah Health Science Center, Salt Lake City, Utah 84132,
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Carpenter BS, Barry RL, Verhey KJ, Allen BL. The heterotrimeric kinesin-2 complex interacts with and regulates GLI protein function. J Cell Sci 2015; 128:1034-50. [PMID: 25588831 DOI: 10.1242/jcs.162552] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
GLI transport to the primary cilium and nucleus is required for proper Hedgehog (HH) signaling; however, the mechanisms that mediate these trafficking events are poorly understood. Kinesin-2 motor proteins regulate ciliary transport of cargo, yet their role in GLI protein function remains unexplored. To examine a role for the heterotrimeric KIF3A-KIF3B-KAP3 kinesin-2 motor complex in regulating GLI activity, we performed a series of structure-function analyses using biochemical, cell signaling and in vivo approaches that define novel specific interactions between GLI proteins and two components of this complex, KAP3 and KIF3A. We find that all three mammalian GLI proteins interact with KAP3 and we map specific interaction sites in both proteins. Furthermore, we find that GLI proteins interact selectively with KIF3A, but not KIF3B, and that GLI interacts synergistically with KAP3 and KIF3A. Using a combination of cell signaling assays and chicken in ovo electroporation, we demonstrate that KAP3 interactions restrict GLI activator function but not GLI repressor function. These data suggest that GLI interactions with KIF3A-KIF3B-KAP3 complexes are essential for proper GLI transcriptional activity.
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Affiliation(s)
- Brandon S Carpenter
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Renee L Barry
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Kristen J Verhey
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Benjamin L Allen
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
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36
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Taschner M, Kotsis F, Braeuer P, Kuehn EW, Lorentzen E. Crystal structures of IFT70/52 and IFT52/46 provide insight into intraflagellar transport B core complex assembly. ACTA ACUST UNITED AC 2015; 207:269-82. [PMID: 25349261 PMCID: PMC4210449 DOI: 10.1083/jcb.201408002] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cilia are microtubule-based organelles that assemble via intraflagellar transport (IFT) and function as signaling hubs on eukaryotic cells. IFT relies on molecular motors and IFT complexes that mediate the contacts with ciliary cargo. To elucidate the architecture of the IFT-B complex, we reconstituted and purified the nonameric IFT-B core from Chlamydomonas reinhardtii and determined the crystal structures of C. reinhardtii IFT70/52 and Tetrahymena IFT52/46 subcomplexes. The 2.5-Å resolution IFT70/52 structure shows that IFT52330-370 is buried deeply within the IFT70 tetratricopeptide repeat superhelix. Furthermore, the polycystic kidney disease protein IFT88 binds IFT52281-329 in a complex that interacts directly with IFT70/IFT52330-381 in trans. The structure of IFT52C/IFT46C was solved at 2.3 Å resolution, and we show that it is essential for IFT-B core integrity by mediating interaction between IFT88/70/52/46 and IFT81/74/27/25/22 subcomplexes. Consistent with this, overexpression of mammalian IFT52C in MDCK cells is dominant-negative and causes IFT protein mislocalization and disrupted ciliogenesis. These data further rationalize several ciliogenesis phenotypes of IFT mutant strains.
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Affiliation(s)
- Michael Taschner
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, D-82152 Martinsried, Germany
| | - Fruzsina Kotsis
- Renal Division, University Hospital Freiburg, D-79106 Freiburg, Germany
| | - Philipp Braeuer
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, D-82152 Martinsried, Germany
| | - E Wolfgang Kuehn
- Renal Division, University Hospital Freiburg, D-79106 Freiburg, Germany BIOSS Center for Biological Signaling Studies, Albert-Ludwig-University, 79104 Freiburg, Germany
| | - Esben Lorentzen
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, D-82152 Martinsried, Germany
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37
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Niwa S. Kinesin superfamily proteins and the regulation of microtubule dynamics in morphogenesis. Anat Sci Int 2014; 90:1-6. [PMID: 25347970 DOI: 10.1007/s12565-014-0259-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 10/08/2014] [Indexed: 11/29/2022]
Abstract
Kinesin superfamily proteins (KIFs) are microtubule-dependent molecular motors that serve as sources of force for intracellular transport and cell division. Recent studies have revealed new roles of KIFs as microtubule stabilizers and depolymerizers, and these activities are fundamental to cellular morphogenesis and mammalian development. KIF2A and KIF19A have microtubule-depolymerizing activities and regulate the neuronal morphology and cilia length, respectively. KIF21A and KIF26A work as microtubule stabilizers that regulate axonal morphology. Morphological defects that are similar to human diseases are observed in mice in which these KIF genes have been deleted. Actually, KIF2A and KIF21A have been identified as causes of human neuronal diseases. In this review, the functions of these atypical KIFs that regulate microtubule dynamics are discussed. Moreover, some interesting unanswered questions and hypothetical answers to them are discussed.
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Affiliation(s)
- Shinsuke Niwa
- Department of Biological Sciences, Stanford University, 385 Serra Mall, Herrin Lab 144, Stanford, CA, 94305, USA,
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38
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Liang Y, Pang Y, Wu Q, Hu Z, Han X, Xu Y, Deng H, Pan J. FLA8/KIF3B Phosphorylation Regulates Kinesin-II Interaction with IFT-B to Control IFT Entry and Turnaround. Dev Cell 2014; 30:585-97. [DOI: 10.1016/j.devcel.2014.07.019] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 07/15/2014] [Accepted: 07/23/2014] [Indexed: 11/28/2022]
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Albracht CD, Rank KC, Obrzut S, Rayment I, Gilbert SP. Kinesin-2 KIF3AB exhibits novel ATPase characteristics. J Biol Chem 2014; 289:27836-48. [PMID: 25122755 DOI: 10.1074/jbc.m114.583914] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
KIF3AB is an N-terminal processive kinesin-2 family member best known for its role in intraflagellar transport. There has been significant interest in KIF3AB in defining the key principles that underlie the processivity of KIF3AB in comparison with homodimeric processive kinesins. To define the ATPase mechanism and coordination of KIF3A and KIF3B stepping, a presteady-state kinetic analysis was pursued. For these studies, a truncated murine KIF3AB was generated. The results presented show that microtubule association was fast at 5.7 μm(-1) s(-1), followed by rate-limiting ADP release at 12.8 s(-1). ATP binding at 7.5 μm(-1) s(-1) was followed by an ATP-promoted isomerization at 84 s(-1) to form the intermediate poised for ATP hydrolysis, which then occurred at 33 s(-1). ATP hydrolysis was required for dissociation of the microtubule·KIF3AB complex, which was observed at 22 s(-1). The dissociation step showed an apparent affinity for ATP that was very weak (K½,ATP at 133 μm). Moreover, the linear fit of the initial ATP concentration dependence of the dissociation kinetics revealed an apparent second-order rate constant at 0.09 μm(-1) s(-1), which is inconsistent with fast ATP binding at 7.5 μm(-1) s(-1) and a Kd ,ATP at 6.1 μm. These results suggest that ATP binding per se cannot account for the apparent weak K½,ATP at 133 μm. The steady-state ATPase Km ,ATP, as well as the dissociation kinetics, reveal an unusual property of KIF3AB that is not yet well understood and also suggests that the mechanochemistry of KIF3AB is tuned somewhat differently from homodimeric processive kinesins.
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Affiliation(s)
- Clayton D Albracht
- From the Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180 and
| | - Katherine C Rank
- the Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Steven Obrzut
- From the Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180 and
| | - Ivan Rayment
- the Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Susan P Gilbert
- From the Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180 and
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40
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Morga B, Bastin P. Getting to the heart of intraflagellar transport using Trypanosoma and Chlamydomonas models: the strength is in their differences. Cilia 2013; 2:16. [PMID: 24289478 PMCID: PMC4015504 DOI: 10.1186/2046-2530-2-16] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 11/11/2013] [Indexed: 11/22/2022] Open
Abstract
Cilia and flagella perform diverse roles in motility and sensory perception, and defects in their construction or their function are responsible for human genetic diseases termed ciliopathies. Cilia and flagella construction relies on intraflagellar transport (IFT), the bi-directional movement of ‘trains’ composed of protein complexes found between axoneme microtubules and the flagellum membrane. Although extensive information about IFT components and their mode of action were discovered in the green algae Chlamydomonas reinhardtii, other model organisms have revealed further insights about IFT. This is the case of Trypanosoma brucei, a flagellated protist responsible for sleeping sickness that is turning out to be an emerging model for studying IFT. In this article, we review different aspects of IFT, based on studies of Chlamydomonas and Trypanosoma. Data available from both models are examined to ask challenging questions about IFT such as the initiation of flagellum construction, the setting-up of IFT and the mode of formation of IFT trains, and their remodeling at the tip as well as their recycling at the base. Another outstanding question is the individual role played by the multiple IFT proteins. The use of different models, bringing their specific biological and experimental advantages, will be invaluable in order to obtain a global understanding of IFT.
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Affiliation(s)
- Benjamin Morga
- Trypanosome Cell Biology Unit, Institut Pasteur and CNRS, URA 2581, 25 rue du Docteur Roux, 75015, Paris, France.
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Lin H, Nauman NP, Albee AJ, Hsu S, Dutcher SK. New mutations in flagellar motors identified by whole genome sequencing in Chlamydomonas. Cilia 2013; 2:14. [PMID: 24229452 PMCID: PMC4132587 DOI: 10.1186/2046-2530-2-14] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 10/02/2013] [Indexed: 02/01/2023] Open
Abstract
Background The building of a cilium or flagellum requires molecular motors and associated
proteins that allow the relocation of proteins from the cell body to the distal
end and the return of proteins to the cell body in a process termed intraflagellar
transport (IFT). IFT trains are carried out by kinesin and back to the cell body
by dynein. Methods We used whole genome sequencing to identify the causative mutations for two
temperature-sensitive flagellar assembly mutants in Chlamydomonas and
validated the changes using reversion analysis. We examined the effect of these
mutations on the localization of IFT81, an IFT complex B protein, the cytoplasmic
dynein heavy chain (DHC1b), and the dynein light intermediate chain (D1bLIC). Results The strains, fla18 and fla24, have mutations in kinesin-2 and
cytoplasmic dynein, respectively. The fla18 mutation alters the same
glutamic acid (E24G) mutated in the fla10-14 allele
(E24K). The fla18 strain loses flagella at 32?C more
rapidly than the E24K allele but less rapidly than the fla10-1
allele. The fla18 mutant loses its flagella by detachment rather than by
shortening. The fla24 mutation falls in cytoplasmic dynein and changes a
completely conserved amino acid (L3243P) in an alpha helix in the AAA5
domain. The fla24 mutant loses its flagella by shortening within 6 hours
at 32?C. DHC1b protein is reduced by 18-fold and D1bLIC is reduced by 16-fold at
21?C compared to wild-type cells. We identified two pseudorevertants
(L3243S and L3243R), which remain flagellated at 32?C.
Although fla24 cells assemble full-length flagella at 21?C, IFT81 protein
localization is dramatically altered. Instead of localizing at the basal body and
along the flagella, IFT81 is concentrated at the proximal end of the flagella. The
pseudorevertants show wild-type IFT81 localization at 21?C, but proximal end
localization of IFT81 at 32?C. Conclusions The change in the AAA5 domain of the cytoplasmic dynein in fla24 may
block the recycling of IFT trains after retrograde transport. It is clear that
different alleles in the flagellar motors reveal different functions and roles.
Multiple alleles will be important for understanding structure-function
relationships.
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Affiliation(s)
- Huawen Lin
- Department of Genetics, Washington University, 660 South Euclid Avenue, St Louis, MO 63110, USA.
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42
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Abstract
Once obscure, the cilium has come into the spotlight during the past decade. It is now clear that aside from generating locomotion by motile cilia, both motile and immotile cilia serve as signaling platforms for the cell. Through both motility and sensory functions, cilia play critical roles in development, homeostasis, and disease. To date, the cilium proteome contains more than 1,000 different proteins, and human genetics is identifying new ciliopathy genes at an increasing pace. Although assigning a function to immotile cilia was a challenge not so long ago, the myriad of signaling pathways, proteins, and biological processes associated with the cilium have now created a new obstacle: how to distill all these interactions into specific themes and mechanisms that may explain how the organelle serves to maintain organism homeostasis. Here, we review the basics of cilia biology, novel functions associated with cilia, and recent advances in cilia genetics, and on the basis of this framework, we further discuss the meaning and significance of ciliary connections.
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Affiliation(s)
- Shiaulou Yuan
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06520
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43
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Song C, Wang ZG, Ding B. Smart nanomachines based on DNA self-assembly. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2013; 9:2382-92. [PMID: 23776091 DOI: 10.1002/smll.201300824] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 04/28/2013] [Indexed: 05/09/2023]
Abstract
DNA-based nanomachines are self-assembled DNA superstructures that harness chemical free energy to perform mechanical work. The development of DNA machines has benefited greatly from the achievements in both structural and dynamic DNA nanotechnology. In this review, the configurations of DNA machines, fuel systems, and operations are discussed to outline the evolving paths of DNA machines. The focus is on the smart mechanical behavior of DNA machines, from the standpoint of upgrading the complexity of DNA nanostructures, cooperative activation of multimachinary systems, and the establishment of a network of the mechanical states. In the end, the challenges are highlighted and possible solutions are proposed to push forward smart DNA nanomachines, with the goal of creating biomimicking systems. Insights are also provided into the potential applications of the DNA machines with designable intelligence.
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Affiliation(s)
- Chen Song
- National Center for Nanoscience and Technology, Beijing 100190, PR China
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44
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Scholey JM. Kinesin-2: a family of heterotrimeric and homodimeric motors with diverse intracellular transport functions. Annu Rev Cell Dev Biol 2013; 29:443-69. [PMID: 23750925 DOI: 10.1146/annurev-cellbio-101512-122335] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Kinesin-2 was first purified as a heterotrimeric, anterograde, microtubule-based motor consisting of two distinct kinesin-related subunits and a novel associated protein (KAP) that is currently best known for its role in intraflagellar transport and ciliogenesis. Subsequent work, however, has revealed diversity in the oligomeric state of different kinesin-2 motors owing to the combinatorial heterodimerization of its subunits and the coexistence of both heterotrimeric and homodimeric kinesin-2 motors in some cells. Although the functional significance of the homo- versus heteromeric organization of kinesin-2 motor subunits and the role of KAP remain uncertain, functional studies suggest that cooperation between different types of kinesin-2 motors or between kinesin-2 and a member of a different motor family can generate diverse patterns of anterograde intracellular transport. Moreover, despite being restricted to ciliated eukaryotes, kinesin-2 motors are now known to drive diverse transport events outside cilia. Here, I review the organization, assembly, phylogeny, biological functions, and motility mechanism of this diverse family of intracellular transport motors.
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Affiliation(s)
- Jonathan M Scholey
- Department of Molecular and Cell Biology, University of California, Davis, California 95616;
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Engel BD, Ishikawa H, Wemmer KA, Geimer S, Wakabayashi KI, Hirono M, Craige B, Pazour GJ, Witman GB, Kamiya R, Marshall WF. The role of retrograde intraflagellar transport in flagellar assembly, maintenance, and function. ACTA ACUST UNITED AC 2013; 199:151-67. [PMID: 23027906 PMCID: PMC3461521 DOI: 10.1083/jcb.201206068] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
An inducible dynein heavy chain 1b mutant reveals that robust retrograde intraflagellar transport is required for flagellar assembly and function but not the maintenance of flagellar length. The maintenance of flagellar length is believed to require both anterograde and retrograde intraflagellar transport (IFT). However, it is difficult to uncouple the functions of retrograde transport from anterograde, as null mutants in dynein heavy chain 1b (DHC1b) have stumpy flagella, demonstrating solely that retrograde IFT is required for flagellar assembly. We isolated a Chlamydomonas reinhardtii mutant (dhc1b-3) with a temperature-sensitive defect in DHC1b, enabling inducible inhibition of retrograde IFT in full-length flagella. Although dhc1b-3 flagella at the nonpermissive temperature (34°C) showed a dramatic reduction of retrograde IFT, they remained nearly full-length for many hours. However, dhc1b-3 cells at 34°C had strong defects in flagellar assembly after cell division or pH shock. Furthermore, dhc1b-3 cells displayed altered phototaxis and flagellar beat. Thus, robust retrograde IFT is required for flagellar assembly and function but is dispensable for the maintenance of flagellar length. Proteomic analysis of dhc1b-3 flagella revealed distinct classes of proteins that change in abundance when retrograde IFT is inhibited.
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Affiliation(s)
- Benjamin D Engel
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
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46
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Brust-Mascher I, Ou G, Scholey JM. Measuring rates of intraflagellar transport along Caenorhabditis elegans sensory cilia using fluorescence microscopy. Methods Enzymol 2013; 524:285-304. [PMID: 23498746 DOI: 10.1016/b978-0-12-397945-2.00016-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Intraflagellar transport (IFT), the kinesin-2 and IFT-dynein-dependent bidirectional movement of multisubunit protein complexes called IFT-particles and associated cargo molecules along ciliary axonemes, is thought to be essential for the assembly and maintenance of virtually all eukaryotic cilia and flagella. Transport assays that allow measurements of the rates of movement of specific, fluorescently tagged, functional components of the IFT machinery, including motors, IFT particle subunits, and putative cargo, were first developed in Caenorhabditis elegans sensory cilia, and they have proved to be an important and valuable tool for dissecting the molecular mechanisms of IFT. We describe how these transport assays are performed in our laboratory and summarize the information that has been obtained by using them concerning the mechanisms of action and regulation of the motors that drive IFT, the composition and organization of the IFT-particles, and the identification of IFT-dynein subunits and ciliary tubulin isotypes as likely cargo proteins of kinesin-2-driven anterograde IFT.
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Affiliation(s)
- Ingrid Brust-Mascher
- Department of Molecular and Cell Biology, University of California at Davis, Davis, California, USA
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47
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Broekhuis JR, Leong WY, Jansen G. Regulation of cilium length and intraflagellar transport. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 303:101-38. [PMID: 23445809 DOI: 10.1016/b978-0-12-407697-6.00003-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Primary cilia are highly conserved sensory organelles that extend from the surface of almost all vertebrate cells. The importance of cilia is evident from their involvement in many diseases, called ciliopathies. Primary cilia contain a microtubular axoneme that is used as a railway for transport of both structural components and signaling proteins. This transport machinery is called intraflagellar transport (IFT). Cilia are dynamic organelles whose presence on the cell surface, morphology, length and function are highly regulated. It is clear that the IFT machinery plays an important role in this regulation. However, it is not clear how, for example environmental cues or cell fate decisions are relayed to modulate IFT and cilium morphology or function. This chapter presents an overview of molecules that have been shown to regulate cilium length and IFT. Several examples where signaling modulates IFT and cilium function are used to discuss the importance of these systems for the cell and for understanding of the etiology of ciliopathies.
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48
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Yu X, Wen H, Cao J, Sun B, Ding T, Li M, Wu H, Long L, Cheng X, Xu G, Zhang F. Temporal and spatial expression of KIF3B after acute spinal cord injury in adult rats. J Mol Neurosci 2012; 49:387-94. [PMID: 23093447 DOI: 10.1007/s12031-012-9901-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 10/01/2012] [Indexed: 12/21/2022]
Abstract
The KIF3 subunit KIF3B was proved to be associated with mitosis. It has been known to be engaged in intracellular transport of neurons. To elucidate the certain expression and biological function in central nervous system, we performed an acute spinal cord contusion injury model in adult rats. Western blot analysis indicated a marked upregulation of KIF3B after spinal cord injury (SCI). Immunohistochemistry revealed wide distribution of KIF3B in spinal cord, including neurons and glial cells. Double immunofluorescent staining for proliferating cell nuclear antigen and phenotype-specific markers showed increases of KIF3B expression in proliferating microglia and astrocytes. Our data suggest that KIF3B may be implicated in the proliferation of microglia and astrocytes after SCI.
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Affiliation(s)
- Xiaowei Yu
- Department of Orthopaedics, Affiliated Hospital of Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
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Live-cell imaging evidence for the ciliary transport of rod photoreceptor opsin by heterotrimeric kinesin-2. J Neurosci 2012; 32:10587-93. [PMID: 22855808 DOI: 10.1523/jneurosci.0015-12.2012] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Primary cilia detect extracellular signals through membrane receptors and channels. The outer segment of a vertebrate photoreceptor cell represents the most elaborate of all primary cilia, containing extraordinarily large amounts of the visual receptor protein, opsin. Because of its high abundance, opsin represents a potential model system for the study of ciliary membrane receptors, including their transport. Here, we have analyzed the movement of ciliary opsin to test whether the highly conserved intraflagellar transport (IFT), as driven by heterotrimeric kinesin-2, is required. Results show that opsin can enter and move along the primary cilium of a nonphotoreceptor cell (an hTERT-RPE1 epithelial cell), suggesting that it can co-opt the basic anterograde motor system of cilia. Fluorescence recovery after photobleaching analysis of cilia of hTERT-RPE1 cells showed that the movement of ciliary opsin was comparable to that of the IFT protein, IFT88. Moreover, the movement of opsin in these cilia, as well as in cilia of mouse rod photoreceptor cells, was reduced significantly when KIF3A, the obligate motor subunit of heterotrimeric kinesin-2, was deficient. These studies therefore provide evidence from live-cell analysis that the conserved heterotrimeric kinesin-2 is required for the normal transport of opsin along the ciliary plasma membrane.
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Doodhi H, Jana SC, Devan P, Mazumdar S, Ray K. Biochemical and molecular dynamic simulation analysis of a weak coiled coil association between kinesin-II stalks. PLoS One 2012; 7:e45981. [PMID: 23029351 PMCID: PMC3461054 DOI: 10.1371/journal.pone.0045981] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 08/27/2012] [Indexed: 01/03/2023] Open
Abstract
DEFINITION Kinesin-2 refers to the family of motor proteins represented by conserved, heterotrimeric kinesin-II and homodimeric Osm3/Kif17 class of motors. BACKGROUND Kinesin-II, a microtubule-based anterograde motor, is composed of three different conserved subunits, named KLP64D, KLP68D and DmKAP in Drosophila. Although previous reports indicated that coiled coil interaction between the middle segments of two dissimilar motor subunits established the heterodimer, the molecular basis of the association is still unknown. METHODOLOGY/PRINCIPAL FINDINGS Here, we present a detailed heterodimeric association model of the KLP64D/68D stalk supported by extensive experimental analysis and molecular dynamic simulations. We find that KLP64D stalk is unstable, but forms a weak coiled coil heteroduplex with the KLP68D stalk when coexpressed in bacteria. Local instabilities, relative affinities between the C-terminal stalk segments, and dynamic long-range interactions along the stalks specify the heterodimerization. Thermal unfolding studies and independent simulations further suggest that interactions between the C-terminal stalk fragments are comparatively stable, whereas the N-terminal stalk reversibly unfolds at ambient temperature. CONCLUSIONS/SIGNIFICANCE Results obtained in this study suggest that coiled coil interaction between the C-terminal stalks of kinesin-II motor subunits is held together through a few hydrophobic and charged interactions. The N-terminal stalk segments are flexible and could uncoil reversibly during a motor walk. This supports the requirement for a flexible coiled coil association between the motor subunits, and its role in motor function needs to be elucidated.
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Affiliation(s)
- Harinath Doodhi
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Swadhin C. Jana
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Pavithra Devan
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Shyamalava Mazumdar
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Krishanu Ray
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
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