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Hoffmann F, Bolz S, Junger K, Klose F, Stehle IF, Ueffing M, Boldt K, Beyer T. Paralog-specific TTC30 regulation of Sonic hedgehog signaling. Front Mol Biosci 2023; 10:1268722. [PMID: 38074101 PMCID: PMC10701685 DOI: 10.3389/fmolb.2023.1268722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 11/09/2023] [Indexed: 02/12/2024] Open
Abstract
The intraflagellar transport (IFT) machinery is essential for cilia assembly, maintenance, and trans-localization of signaling proteins. The IFT machinery consists of two large multiprotein complexes, one of which is the IFT-B. TTC30A and TTC30B are integral components of this complex and were previously shown to have redundant functions in the context of IFT, preventing the disruption of IFT-B and, thus, having a severe ciliogenesis defect upon loss of one paralog. In this study, we re-analyzed the paralog-specific protein complexes and discovered a potential involvement of TTC30A or TTC30B in ciliary signaling. Specifically, we investigated a TTC30A-specific interaction with protein kinase A catalytic subunit α, a negative regulator of Sonic hedgehog (Shh) signaling. Defects in this ciliary signaling pathway are often correlated to synpolydactyly, which, intriguingly, is also linked to a rare TTC30 variant. For an in-depth analysis of this unique interaction and the influence on Shh, TTC30A or B single- and double-knockout hTERT-RPE1 were employed, as well as rescue cells harboring wildtype TTC30 or the corresponding mutation. We could show that mutant TTC30A inhibits the ciliary localization of Smoothened. This observed effect is independent of Patched1 but associated with a distinct phosphorylated PKA substrate accumulation upon treatment with forskolin. This rather prominent phenotype was attenuated in mutant TTC30B. Mass spectrometry analysis of wildtype versus mutated TTC30A or TTC30B uncovered differences in protein complex patterns and identified an impaired TTC30A-IFT57 interaction as the possible link leading to synpolydactyly. We could observe no impact on cilia assembly, leading to the hypothesis that a slight decrease in IFT-B binding can be compensated, but mild phenotypes, like synpolydactyly, can be induced by subtle signaling changes. Our systematic approach revealed the paralog-specific influence of TTC30A KO and mutated TTC30A on the activity of PRKACA and the uptake of Smoothened into the cilium, resulting in a downregulation of Shh. This downregulation, combined with interactome alterations, suggests a potential mechanism of how mutant TTC30A is linked to synpolydactyly.
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Affiliation(s)
- Felix Hoffmann
- Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | | | | | | | | | | | | | - Tina Beyer
- *Correspondence: Felix Hoffmann, ; Tina Beyer,
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2
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Chen H, Yang QL, Xu JX, Deng X, Zhang YJ, Liu T, Rots MG, Xu GL, Huang KY. Efficient methods for multiple types of precise gene-editing in Chlamydomonas. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023. [PMID: 37310200 DOI: 10.1111/tpj.16265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 04/20/2023] [Accepted: 04/26/2023] [Indexed: 06/14/2023]
Abstract
Precise gene-editing using CRISPR/Cas9 technology remains a long-standing challenge, especially for genes with low expression and no selectable phenotypes in Chlamydomonas reinhardtii, a classic model for photosynthesis and cilia research. Here, we developed a multi-type and precise genetic manipulation method in which a DNA break was generated by Cas9 nuclease and the repair was mediated using a homologous DNA template. The efficacy of this method was demonstrated for several types of gene editing, including inactivation of two low-expression genes (CrTET1 and CrKU80), the introduction of a FLAG-HA epitope tag into VIPP1, IFT46, CrTET1 and CrKU80 genes, and placing a YFP tag into VIPP1 and IFT46 for live-cell imaging. We also successfully performed a single amino acid substitution for the FLA3, FLA10 and FTSY genes, and documented the attainment of the anticipated phenotypes. Lastly, we demonstrated that precise fragment deletion from the 3'-UTR of MAA7 and VIPP1 resulted in a stable knock-down effect. Overall, our study has established efficient methods for multiple types of precise gene editing in Chlamydomonas, enabling substitution, insertion and deletion at the base resolution, thus improving the potential of this alga in both basic research and industrial applications.
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Affiliation(s)
- Hui Chen
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Qing-Lin Yang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Jia-Xi Xu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xuan Deng
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Yun-Jie Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Ting Liu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Marianne G Rots
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, 9713 GZ, Groningen, The Netherlands
| | - Guo-Liang Xu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Shanghai Key Laboratory of Medical Epigenetics, Laboratory of Cancer Epigenetics, Institutes of Biomedical Sciences, Medical College of Fudan University, Chinese Academy of Medical Sciences (RU069), Shanghai, China
| | - Kai-Yao Huang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
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Hibbard JVK, Vázquez N, Wallingford JB. Cilia proteins getting to work - how do they commute from the cytoplasm to the base of cilia? J Cell Sci 2022; 135:jcs259444. [PMID: 36073764 PMCID: PMC9482345 DOI: 10.1242/jcs.259444] [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] [Indexed: 11/20/2022] Open
Abstract
Cilia are multifunctional organelles that originated with the last eukaryotic common ancestor and play central roles in the life cycles of diverse organisms. The motile flagella that move single cells like sperm or unicellular organisms, the motile cilia on animal multiciliated cells that generate fluid flow in organs, and the immotile primary cilia that decorate nearly all cells in animals share many protein components in common, yet each also requires specialized proteins to perform their specialized functions. Despite a now-advanced understanding of how such proteins are transported within cilia, we still know very little about how they are transported from their sites of synthesis through the cytoplasm to the ciliary base. Here, we review the literature concerning this underappreciated topic in ciliary cell biology. We discuss both general mechanisms, as well as specific examples of motor-driven active transport and passive transport via diffusion-and-capture. We then provide deeper discussion of specific, illustrative examples, such as the diverse array of protein subunits that together comprise the intraflagellar transport (IFT) system and the multi-protein axonemal dynein motors that drive beating of motile cilia. We hope this Review will spur further work, shedding light not only on ciliogenesis and ciliary signaling, but also on intracellular transport in general.
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Affiliation(s)
| | | | - John B. Wallingford
- Department of Molecular Biosciences, University of Texas, Austin, TX 78751, USA
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Rah G, Cha H, Kim J, Song J, Kim H, Oh YK, Ahn C, Kang M, Kim J, Yoo KH, Kim MJ, Ko HW, Ko JY, Park JH. KLC3 Regulates Ciliary Trafficking and Cyst Progression in CILK1 Deficiency-Related Polycystic Kidney Disease. J Am Soc Nephrol 2022; 33:1726-1741. [PMID: 35961787 PMCID: PMC9529174 DOI: 10.1681/asn.2021111455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 05/23/2022] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Ciliogenesis-associated kinase 1 (CILK1) is a ciliary gene that localizes in primary cilia and regulates ciliary transport. Mutations in CILK1 cause various ciliopathies. However, the pathogenesis of CILK1-deficient kidney disease is unknown. METHODS To examine whether CILK1 deficiency causes PKD accompanied by abnormal cilia, we generated mice with deletion of Cilk1 in cells of the renal collecting duct. A yeast two-hybrid system and coimmunoprecipitation (co-IP) were used to identify a novel regulator, kinesin light chain-3 (KLC3), of ciliary trafficking and cyst progression in the Cilk1-deficient model. Immunocytochemistry and co-IP were used to examine the effect of KLC3 on ciliary trafficking of the IFT-B complex and EGFR. We evaluated the effects of these genes on ciliary trafficking and cyst progression by modulating CILK1 and KLC3 expression levels. RESULTS CILK1 deficiency leads to PKD accompanied by abnormal ciliary trafficking. KLC3 interacts with CILK1 at cilia bases and is increased in cyst-lining cells of CILK1-deficient mice. KLC3 overexpression promotes ciliary recruitment of IFT-B and EGFR in the CILK1 deficiency condition, which contributes to the ciliary defect in cystogenesis. Reduction in KLC3 rescued the ciliary defects and inhibited cyst progression caused by CILK1 deficiency. CONCLUSIONS Our findings suggest that CILK1 deficiency in renal collecting ducts leads to PKD and promotes ciliary trafficking via increased KLC3.
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Affiliation(s)
- Gyuyeong Rah
- Department of Biological Science, Sookmyung Women’s University, Seoul, Korea
| | - Hwayeon Cha
- Department of Biological Science, Sookmyung Women’s University, Seoul, Korea
| | - Joohee Kim
- Department of Biological Science, Sookmyung Women’s University, Seoul, Korea
| | - Jieun Song
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea
| | - Hyunho Kim
- Center for Medical Innovation, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Yun Kyu Oh
- Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul, Korea
| | - Curie Ahn
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Minyong Kang
- Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jongmin Kim
- Department of Biological Science, Sookmyung Women’s University, Seoul, Korea
| | - Kyung Hyun Yoo
- Department of Biological Science, Sookmyung Women’s University, Seoul, Korea
| | - Min Jung Kim
- Department of Biological Science, Sookmyung Women’s University, Seoul, Korea
| | - Hyuk Wan Ko
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea
| | - Je Yeong Ko
- Department of Biological Science, Sookmyung Women’s University, Seoul, Korea
| | - Jong Hoon Park
- Department of Biological Science, Sookmyung Women’s University, Seoul, Korea
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Dai J, Zhang G, Alkhofash RA, Mekonnen B, Saravanan S, Xue B, Fan ZC, Betleja E, Cole DG, Liu P, Lechtreck K. Loss of ARL13 impedes BBSome-dependent cargo export from Chlamydomonas cilia. J Cell Biol 2022; 221:213429. [PMID: 36040375 PMCID: PMC9436004 DOI: 10.1083/jcb.202201050] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 05/12/2022] [Accepted: 07/11/2022] [Indexed: 12/25/2022] Open
Abstract
The GTPase Arl13b participates in ciliary protein transport, but its contribution to intraflagellar transport (IFT), the main motor-based protein shuttle of cilia, remains largely unknown. Chlamydomonas arl13 mutant cilia were characterized by both abnormal reduction and accumulation of select membrane-associated proteins. With respect to the latter, a similar set of proteins including phospholipase D (PLD) also accumulated in BBSome-deficient cilia. IFT and BBSome traffic were apparently normal in arl13. However, transport of PLD, which in control cells moves by BBSome-dependent IFT, was impaired in arl13, causing PLD to accumulate in cilia. ARL13 only rarely and transiently traveled by IFT, indicating that it is not a co-migrating adapter securing PLD to IFT trains. In conclusion, the loss of Chlamydomonas ARL13 impedes BBSome-dependent protein transport, resulting in overlapping biochemical defects in arl13 and bbs mutant cilia.
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Affiliation(s)
- Jin Dai
- Cellular Biology, University of Georgia, Athens, GA
| | - Gui Zhang
- Cellular Biology, University of Georgia, Athens, GA
| | | | | | | | - Bin Xue
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Zhen-Chuan Fan
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | | | | | - Peiwei Liu
- College of Life Science, Shandong Normal University, Jinan, Shandong, China
| | - Karl Lechtreck
- Cellular Biology, University of Georgia, Athens, GA,Correspondence to Karl F. Lechtreck:
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6
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Hibbard JVK, Vazquez N, Satija R, Wallingford JB. Protein turnover dynamics suggest a diffusion-to-capture mechanism for peri-basal body recruitment and retention of intraflagellar transport proteins. Mol Biol Cell 2021; 32:1171-1180. [PMID: 33826363 PMCID: PMC8351562 DOI: 10.1091/mbc.e20-11-0717] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Intraflagellar transport (IFT) is essential for construction and maintenance of cilia. IFT proteins concentrate at the basal body where they are thought to assemble into trains and bind cargoes for transport. To study the mechanisms of IFT recruitment to this peri-basal body pool, we quantified protein dynamics of eight IFT proteins, as well as five other basal body localizing proteins using fluorescence recovery after photobleaching in vertebrate multiciliated cells. We found that members of the IFT-A and IFT-B protein complexes show distinct turnover kinetics from other basal body components. Additionally, known IFT subcomplexes displayed shared dynamics, suggesting shared basal body recruitment and/or retention mechanisms. Finally, we evaluated the mechanisms of basal body recruitment by depolymerizing cytosolic MTs, which suggested that IFT proteins are recruited to basal bodies through a diffusion-to-capture mechanism. Our survey of IFT protein dynamics provides new insights into IFT recruitment to basal bodies, a crucial step in ciliogenesis and ciliary signaling.
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Affiliation(s)
- Jaime V K Hibbard
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712
| | - Neftali Vazquez
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712
| | - Rohit Satija
- California Institute of Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720
| | - John B Wallingford
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712
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7
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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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8
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Abstract
Primary cilia project in a single copy from the surface of most vertebrate cell types; they detect and transmit extracellular cues to regulate diverse cellular processes during development and to maintain tissue homeostasis. The sensory capacity of primary cilia relies on the coordinated trafficking and temporal localization of specific receptors and associated signal transduction modules in the cilium. The canonical Hedgehog (HH) pathway, for example, is a bona fide ciliary signalling system that regulates cell fate and self-renewal in development and tissue homeostasis. Specific receptors and associated signal transduction proteins can also localize to primary cilia in a cell type-dependent manner; available evidence suggests that the ciliary constellation of these proteins can temporally change to allow the cell to adapt to specific developmental and homeostatic cues. Consistent with important roles for primary cilia in signalling, mutations that lead to their dysfunction underlie a pleiotropic group of diseases and syndromic disorders termed ciliopathies, which affect many different tissues and organs of the body. In this Review, we highlight central mechanisms by which primary cilia coordinate HH, G protein-coupled receptor, WNT, receptor tyrosine kinase and transforming growth factor-β (TGFβ)/bone morphogenetic protein (BMP) signalling and illustrate how defects in the balanced output of ciliary signalling events are coupled to developmental disorders and disease progression.
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9
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Werner S, Pimenta-Marques A, Bettencourt-Dias M. Maintaining centrosomes and cilia. J Cell Sci 2017; 130:3789-3800. [DOI: 10.1242/jcs.203505] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
ABSTRACT
Centrosomes and cilia are present in organisms from all branches of the eukaryotic tree of life. These structures are composed of microtubules and various other proteins, and are required for a plethora of cell processes such as structuring the cytoskeleton, sensing the environment, and motility. Deregulation of centrosome and cilium components leads to a wide range of diseases, some of which are incompatible with life. Centrosomes and cilia are thought to be very stable and can persist over long periods of time. However, these structures can disappear in certain developmental stages and diseases. Moreover, some centrosome and cilia components are quite dynamic. While a large body of knowledge has been produced regarding the biogenesis of these structures, little is known about how they are maintained. In this Review, we propose the existence of specific centrosome and cilia maintenance programs, which are regulated during development and homeostasis, and when deregulated can lead to disease.
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Affiliation(s)
- Sascha Werner
- Cell Cycle Regulation Lab, Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal
| | - Ana Pimenta-Marques
- Cell Cycle Regulation Lab, Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal
| | - Mónica Bettencourt-Dias
- Cell Cycle Regulation Lab, Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal
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10
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Liang Y, Meng D, Zhu B, Pan J. Mechanism of ciliary disassembly. Cell Mol Life Sci 2016; 73:1787-802. [PMID: 26869233 PMCID: PMC11108551 DOI: 10.1007/s00018-016-2148-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 01/22/2016] [Accepted: 01/25/2016] [Indexed: 12/19/2022]
Abstract
As motile organelles and sensors, cilia play pivotal roles in cell physiology, development and organ homeostasis. Ciliary defects are associated with a class of cilia-related diseases or developmental disorders, termed ciliopathies. Even though the presence of cilia is required for diverse functions, cilia can be removed through ciliary shortening or resorption that necessitates disassembly of the cilium, which occurs normally during cell cycle progression, cell differentiation and in response to cellular stress. The functional significance of ciliary resorption is highlighted in controlling the G1-S transition during cell cycle progression. Internal or external cues that trigger ciliary resorption initiate signaling cascades that regulate several downstream events including depolymerization of axonemal microtubules, dynamic changes in actin and the ciliary membrane, regulation of intraflagellar transport and posttranslational modifications of ciliary proteins. To ensure ciliary resorption, both the active disassembly of the cilium and the simultaneous inhibition of ciliary assembly must be coordinately regulated.
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Affiliation(s)
- Yinwen Liang
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Dan Meng
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Bing Zhu
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Junmin Pan
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong, China.
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11
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Vannuccini E, Paccagnini E, Cantele F, Gentile M, Dini D, Fino F, Diener D, Mencarelli C, Lupetti P. Two classes of short intraflagellar transport train with different 3D structures are present in Chlamydomonas flagella. J Cell Sci 2016; 129:2064-74. [PMID: 27044756 DOI: 10.1242/jcs.183244] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 03/30/2016] [Indexed: 12/18/2022] Open
Abstract
Intraflagellar transport (IFT) is responsible for the bidirectional trafficking of molecular components required for the elongation and maintenance of eukaryotic cilia and flagella. Cargo is transported by IFT 'trains', linear rows of multiprotein particles moved by molecular motors along the axonemal doublets. We have previously described two structurally distinct categories of 'long' and 'short' trains. Here, we analyse the relative number of these trains throughout flagellar regeneration and show that long trains are most abundant at the beginning of flagellar growth whereas short trains gradually increase in number as flagella elongate. These observations are incompatible with the previous hypothesis that short trains are derived solely from the reorganization of long trains at the flagellar tip. We demonstrate with electron tomography the existence of two distinct ultrastructural organizations for the short trains, we name these 'narrow' and 'wide', and provide the first 3D model of the narrow short trains. These trains are characterized by tri-lobed units, which repeat longitudinally every 16 nm and contact protofilament 7 of the B-tubule. Functional implications of the new structural evidence are discussed.
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Affiliation(s)
- Elisa Vannuccini
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Eugenio Paccagnini
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Francesca Cantele
- Dipartimento di Chimica, Università degli Studi di Milano, Via Camillo Golgi 19, 20133 Milan, Italy
| | - Mariangela Gentile
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Daniele Dini
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Federica Fino
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Dennis Diener
- Department of Molecular, Cellular and Developmental Biology, Yale University, 219 Prospect Street, New Haven, CT 06520, USA
| | - Caterina Mencarelli
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Pietro Lupetti
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
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12
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Viswanadha R, Hunter EL, Yamamoto R, Wirschell M, Alford LM, Dutcher SK, Sale WS. The ciliary inner dynein arm, I1 dynein, is assembled in the cytoplasm and transported by IFT before axonemal docking. Cytoskeleton (Hoboken) 2014; 71:573-86. [PMID: 25252184 DOI: 10.1002/cm.21192] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 09/11/2014] [Accepted: 09/15/2014] [Indexed: 01/11/2023]
Abstract
To determine mechanisms of assembly of ciliary dyneins, we focused on the Chlamydomonas inner dynein arm, I1 dynein, also known as dynein f. I1 dynein assembles in the cytoplasm as a 20S complex similar to the 20S I1 dynein complex isolated from the axoneme. The intermediate chain subunit, IC140 (IDA7), and heavy chains (IDA1, IDA2) are required for 20S I1 dynein preassembly in the cytoplasm. Unlike I1 dynein derived from the axoneme, the cytoplasmic 20S I1 complex will not rebind I1-deficient axonemes in vitro. To test the hypothesis that I1 dynein is transported to the distal tip of the cilia for assembly in the axoneme, we performed cytoplasmic complementation in dikaryons formed between wild-type and I1 dynein mutant cells. Rescue of I1 dynein assembly in mutant cilia occurred first at the distal tip and then proceeded toward the proximal axoneme. Notably, in contrast to other combinations, I1 dynein assembly was significantly delayed in dikaryons formed between ida7 and ida3. Furthermore, rescue of I1 dynein assembly required new protein synthesis in the ida7 × ida3 dikaryons. On the basis of the additional observations, we postulate that IDA3 is required for 20S I1 dynein transport. Cytoplasmic complementation in dikaryons using the conditional kinesin-2 mutant, fla10-1 revealed that transport of I1 dynein is dependent on kinesin-2 activity. Thus, I1 dynein complex assembly depends upon IFT for transport to the ciliary distal tip prior to docking in the axoneme.
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Affiliation(s)
- Rasagnya Viswanadha
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia
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13
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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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14
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Abstract
Cilia and flagella are organelles of the cell body present in many eukaryotic cells. Although their basic structure is well conserved from unicellular organisms to mammals, they show amazing diversity in number, structure, molecular composition, disposition and function. These complex organelles are generally assembled by the action of intraflagellar transport, which is powered by kinesin and dynein motor proteins. Several types of kinesins can function in flagella. They all have a well-conserved motor domain with characteristic signatures, but display exhaustive diversification of some domains. This diversity can be explained by the multitude of functions fulfilled by these proteins (transport of cargoes along microtubules, polymerization and depolymerization of microtubules). Functional and phylogenetic analyses reveal that at least seven kinesin families are involved in flagellum assembly and function. In protists, where cilia and flagella fulfill many essential roles, this diversity of function is also observed.
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Affiliation(s)
- William Marande
- Adaptation Processes of Protists to their Environment, UMR7245 CNRS/MNHN Muséum National d'Histoire Naturelle, 57, rue Cuvier, CP52, 75231 Paris, France
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15
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Mittelmeier TM, Boyd JS, Lamb MR, Dieckmann CL. Asymmetric properties of the Chlamydomonas reinhardtii cytoskeleton direct rhodopsin photoreceptor localization. J Cell Biol 2011; 193:741-53. [PMID: 21555459 PMCID: PMC3166873 DOI: 10.1083/jcb.201009131] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Accepted: 04/06/2011] [Indexed: 11/22/2022] Open
Abstract
The eyespot of the unicellular green alga Chlamydomonas reinhardtii is a photoreceptive organelle required for phototaxis. Relative to the anterior flagella, the eyespot is asymmetrically positioned adjacent to the daughter four-membered rootlet (D4), a unique bundle of acetylated microtubules extending from the daughter basal body toward the posterior of the cell. Here, we detail the relationship between the rhodopsin eyespot photoreceptor Channelrhodopsin 1 (ChR1) and acetylated microtubules. In wild-type cells, ChR1 was observed in an equatorial patch adjacent to D4 near the end of the acetylated microtubules and along the D4 rootlet. In cells with cytoskeletal protein mutations, supernumerary ChR1 patches remained adjacent to acetylated microtubules. In mlt1 (multieyed) mutant cells, supernumerary photoreceptor patches were not restricted to the D4 rootlet, and more anterior eyespots correlated with shorter acetylated microtubule rootlets. The data suggest a model in which photoreceptor localization is dependent on microtubule-based trafficking selective for the D4 rootlet, which is perturbed in mlt1 mutant cells.
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Affiliation(s)
- Telsa M. Mittelmeier
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721
| | - Joseph S. Boyd
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721
| | - Mary Rose Lamb
- Department of Biology, University of Puget Sound, Tacoma, WA 98416
| | - Carol L. Dieckmann
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721
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16
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Keller LC, Wemmer KA, Marshall WF. Influence of centriole number on mitotic spindle length and symmetry. Cytoskeleton (Hoboken) 2010; 67:504-18. [PMID: 20540087 DOI: 10.1002/cm.20462] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The functional role of centrioles or basal bodies in mitotic spindle assembly and function is currently unclear. Although supernumerary centrioles have been associated with multipolar spindles in cancer cells, suggesting centriole number might dictate spindle polarity, bipolar spindles are able to assemble in the complete absence of centrioles, suggesting a level of centriole-independence in the spindle assembly pathway. In this report we perturb centriole number using mutations in Chlamydomonas reinhardtii, and measure the response of the mitotic spindle to these perturbations in centriole number. Although altered centriole number increased the frequency of monopolar and multipolar spindles, the majority of spindles remained bipolar regardless of the centriole number. But even when spindles were bipolar, abnormal centriole numbers led to asymmetries in tubulin distribution, half-spindle length and spindle pole focus. Half spindle length correlated directly with number of centrioles at a pole, such that an imbalance in centriole number between the two poles of a bipolar spindle correlated with increased asymmetry between half spindle lengths. These results are consistent with centrioles playing an active role in regulating mitotic spindle length. Mutants with centriole number alteration also show increased cytokinesis defects, but these do not correlate with centriole number in the dividing cell and may therefore reflect downstream consequences of defects in preceding cell divisions.
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Affiliation(s)
- Lani C Keller
- Department of Biochemistry and Biophysics, UCSF, San Francisco, California 94158, USA
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17
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Life with eight flagella: flagellar assembly and division in Giardia. Curr Opin Microbiol 2010; 13:480-90. [PMID: 20580308 DOI: 10.1016/j.mib.2010.05.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Revised: 05/26/2010] [Accepted: 05/27/2010] [Indexed: 11/23/2022]
Abstract
Flagellar movement in Giardia, a common intestinal parasitic protist, is crucial to its survival in the host. Each axoneme is unique in possessing a long, cytoplasmic portion as well as a membrane-bound portion. Intraflagellar transport (IFT) is required for the assembly of membrane-bound regions, yet the cytoplasmic regions may be assembled by IFT-independent mechanisms. Steady-state axoneme length is maintained by IFT and by intrinsic and active microtubule dynamics. Following mitosis and before their segregation, giardial flagella undergo a multigenerational division cycle in which the parental eight flagella migrate and reposition to different cellular locations; eight new flagella are assembled de novo. Each daughter cell thus inherits four mature and four newly synthesized flagella.
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18
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Piasecki BP, Silflow CD. The UNI1 and UNI2 genes function in the transition of triplet to doublet microtubules between the centriole and cilium in Chlamydomonas. Mol Biol Cell 2008; 20:368-78. [PMID: 19005206 DOI: 10.1091/mbc.e08-09-0900] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
One fundamental role of the centriole in eukaryotic cells is to nucleate the growth of cilia. The unicellular alga Chlamydomonas reinhardtii provides a simple genetic system to study the role of the centriole in ciliogenesis. Wild-type cells are biflagellate, but "uni" mutations result in failure of some centrioles (basal bodies) to assemble cilia (flagella). Serial transverse sections through basal bodies in uni1 and uni2 single and double mutant cells revealed a previously undescribed defect in the transition of triplet microtubules to doublet microtubules, a defect correlated with failure to assemble flagella. Phosphorylation of the Uni2 protein is reduced in uni1 mutant cells. Immunogold electron microscopy showed that the Uni2 protein localizes at the distal end of the basal body where microtubule transition occurs. These results provide the first mechanistic insights into the function of UNI1 and UNI2 genes in the pathway mediating assembly of doublet microtubules in the axoneme from triplet microtubules in the basal body template.
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Affiliation(s)
- Brian P Piasecki
- Department of Plant Biology, University of Minnesota, St. Paul, MN 55108, USA
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19
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Ahmed NT, Gao C, Lucker BF, Cole DG, Mitchell DR. ODA16 aids axonemal outer row dynein assembly through an interaction with the intraflagellar transport machinery. ACTA ACUST UNITED AC 2008; 183:313-22. [PMID: 18852297 PMCID: PMC2568026 DOI: 10.1083/jcb.200802025] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Formation of flagellar outer dynein arms in Chlamydomonas reinhardtii requires the ODA16 protein at a previously uncharacterized assembly step. Here, we show that dynein extracted from wild-type axonemes can rebind to oda16 axonemes in vitro, and dynein in oda16 cytoplasmic extracts can bind to docking sites on pf28 (oda) axonemes, which is consistent with a role for ODA16 in dynein transport, rather than subunit preassembly or binding site formation. ODA16 localization resembles that seen for intraflagellar transport (IFT) proteins, and flagellar abundance of ODA16 depends on IFT. Yeast two-hybrid analysis with mammalian homologues identified an IFT complex B subunit, IFT46, as a directly interacting partner of ODA16. Interaction between Chlamydomonas ODA16 and IFT46 was confirmed through in vitro pull-down assays and coimmunoprecipitation from flagellar extracts. ODA16 appears to function as a cargo-specific adaptor between IFT particles and outer row dynein needed for efficient dynein transport into the flagellar compartment.
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Affiliation(s)
- Noveera T Ahmed
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA
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20
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Hoeng JC, Dawson SC, House SA, Sagolla MS, Pham JK, Mancuso JJ, Löwe J, Cande WZ. High-resolution crystal structure and in vivo function of a kinesin-2 homologue in Giardia intestinalis. Mol Biol Cell 2008; 19:3124-37. [PMID: 18463165 DOI: 10.1091/mbc.e07-11-1156] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
A critical component of flagellar assembly, the kinesin-2 heterotrimeric complex powers the anterograde movement of proteinaceous rafts along the outer doublet of axonemes in intraflagellar transport (IFT). We present the first high-resolution structures of a kinesin-2 motor domain and an ATP hydrolysis-deficient motor domain mutant from the parasitic protist Giardia intestinalis. The high-resolution crystal structures of G. intestinalis wild-type kinesin-2 (GiKIN2a) motor domain, with its docked neck linker and the hydrolysis-deficient mutant GiKIN2aT104N were solved in a complex with ADP and Mg(2+) at 1.6 and 1.8 A resolutions, respectively. These high-resolution structures provide unique insight into the nucleotide coordination within the active site. G. intestinalis has eight flagella, and we demonstrate that both kinesin-2 homologues and IFT proteins localize to both cytoplasmic and membrane-bound regions of axonemes, with foci at cell body exit points and the distal flagellar tips. We demonstrate that the T104N mutation causes GiKIN2a to act as a rigor mutant in vitro. Overexpression of GiKIN2aT104N results in significant inhibition of flagellar assembly in the caudal, ventral, and posterolateral flagellar pairs. Thus we confirm the conserved evolutionary structure and functional role of kinesin-2 as the anterograde IFT motor in G. intestinalis.
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Affiliation(s)
- J C Hoeng
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 2QH, United Kingdom
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21
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Quan L, Xiao R, Li W, Oh SA, Kong H, Ambrose JC, Malcos JL, Cyr R, Twell D, Ma H. Functional divergence of the duplicated AtKIN14a and AtKIN14b genes: critical roles in Arabidopsis meiosis and gametophyte development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2008; 53:1013-26. [PMID: 18088313 DOI: 10.1111/j.1365-313x.2007.03391.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Gene duplication is important for gene family evolution, allowing for functional divergence and innovation. In flowering plants, duplicated genes are widely observed, and functional redundancy of closely related duplicates has been reported, but few cases of functional divergence of close duplicates have been described. Here, we show that the Arabidopsis AtKIN14a and AtKIN14b genes encoding highly similar kinesins are two of the most closely related Arabidopsis paralogs, which were formed by a duplication event that occurred after the split of Arabidopsis and poplar. In addition, AtKIN14a and AtKIN14b exhibit varying degrees of coding sequence divergence. Further genetic studies of plants carrying atkin14a and/or atkin14b mutations indicate that, although these two genes have similar functions, there is clear evidence for functional divergence. Although both genes are important for male and female meiosis, AtKIN14a plays a more critical role in male meiosis than AtKIN14b. Moreover, either one of these two genes is necessary and sufficient for gametophyte development, indicating that they are redundant for this function. Therefore, AtKIN14a and AtKIN14b together play important roles in controlling plant reproductive development. Our results suggest that the AtKIN14a and AtKIN14b genes have retained similar functions in gametophyte development and female meiosis, but have evolved partially distinct functions in male meiosis, with AtKIN14a playing a more substantive role.
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Affiliation(s)
- Li Quan
- Department of Biology, the Pennsylvania State University, University Park, PA 16802, USA
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22
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Dawson SC, Sagolla MS, Mancuso JJ, Woessner DJ, House SA, Fritz-Laylin L, Cande WZ. Kinesin-13 regulates flagellar, interphase, and mitotic microtubule dynamics in Giardia intestinalis. EUKARYOTIC CELL 2007; 6:2354-64. [PMID: 17766466 PMCID: PMC2168246 DOI: 10.1128/ec.00128-07] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Microtubule depolymerization dynamics in the spindle are regulated by kinesin-13, a nonprocessive kinesin motor protein that depolymerizes microtubules at the plus and minus ends. Here we show that a single kinesin-13 homolog regulates flagellar length dynamics, as well as other interphase and mitotic dynamics in Giardia intestinalis, a widespread parasitic diplomonad protist. Both green fluorescent protein-tagged kinesin-13 and EB1 (a plus-end tracking protein) localize to the plus ends of mitotic and interphase microtubules, including a novel localization to the eight flagellar tips, cytoplasmic anterior axonemes, and the median body. The ectopic expression of a kinesin-13 (S280N) rigor mutant construct caused significant elongation of the eight flagella with significant decreases in the median body volume and resulted in mitotic defects. Notably, drugs that disrupt normal interphase and mitotic microtubule dynamics also affected flagellar length in Giardia. Our study extends recent work on interphase and mitotic kinesin-13 functioning in metazoans to include a role in regulating flagellar length dynamics. We suggest that kinesin-13 universally regulates both mitotic and interphase microtubule dynamics in diverse microbial eukaryotes and propose that axonemal microtubules are subject to the same regulation of microtubule dynamics as other dynamic microtubule arrays. Finally, the present study represents the first use of a dominant-negative strategy to disrupt normal protein function in Giardia and provides important insights into giardial microtubule dynamics with relevance to the development of antigiardial compounds that target critical functions of kinesins in the giardial life cycle.
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Affiliation(s)
- Scott C Dawson
- Department of Molecular and Cell Biology, University of California-Berkeley, 341 LSA Bldg., Berkeley, California 94720, USA.
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23
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Haraguchi K, Hayashi T, Jimbo T, Yamamoto T, Akiyama T. Role of the Kinesin-2 Family Protein, KIF3, during Mitosis. J Biol Chem 2006; 281:4094-9. [PMID: 16298999 DOI: 10.1074/jbc.m507028200] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
During mitosis, kinesin and dynein motor proteins play critical roles in the equal segregation of chromosomes between two daughter cells. Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. We have shown here that the kinesin-2 complex is localized with components of the mitotic apparatus such as spindle microtubules and centrosomes. Furthermore, we found that expression of a mutant KIF3B, which is able to associate with KIF3A but not KAP3 in NIH3T3 cells, caused chromosomal aneuploidy and abnormal spindle formation. Our data suggested that the kinesin-2 complex plays an important role not only in interphase but also in mitosis.
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Affiliation(s)
- Keiko Haraguchi
- Laboratory of Molecular and Genetic Information, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Bunkyo-ku, Japan
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24
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Miller MS, Esparza JM, Lippa AM, Lux FG, Cole DG, Dutcher SK. Mutant kinesin-2 motor subunits increase chromosome loss. Mol Biol Cell 2005; 16:3810-20. [PMID: 15944218 PMCID: PMC1182318 DOI: 10.1091/mbc.e05-05-0404] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The Chlamydomonas anterograde intraflagellar transport motor, kinesin-2, is isolated as a heterotrimeric complex containing two motor subunits and a nonmotor subunit known as kinesin-associated polypeptide or KAP. One of the two motor subunits is encoded by the FLA10 gene. The sequence of the second motor subunit was obtained by mass spectrometry and sequencing. It shows 46.9% identity with the Fla10 motor subunit and the gene maps to linkage group XII/XIII near RPL9. The temperature-sensitive flagellar assembly mutants fla1 and fla8 are linked to this kinesin-2 motor subunit. In each strain, a unique single point mutation gives rise to a unique single amino acid substitution within the motor domain. The fla8 strain is named fla8-1 and the fla1 strain is named fla8-2. The fla8 and fla10 alleles show a chromosome loss phenotype. To analyze this chromosome loss phenotype, intragenic revertants of fla8-1, fla8-2, and fla10-14 were generated. The analysis of the mutants and the revertants demonstrates the importance of a pocket in the amino terminus of these motor subunits for both motor activity and for a novel, dominant effect on the fidelity of chromosome segregation.
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Affiliation(s)
- Mark S Miller
- Department of Microbiology, Molecular Biology, and Biochemistry, University of Idaho, Moscow, ID 83844-3052, USA
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25
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Mueller J, Perrone CA, Bower R, Cole DG, Porter ME. The FLA3 KAP subunit is required for localization of kinesin-2 to the site of flagellar assembly and processive anterograde intraflagellar transport. Mol Biol Cell 2004; 16:1341-54. [PMID: 15616187 PMCID: PMC551497 DOI: 10.1091/mbc.e04-10-0931] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Intraflagellar transport (IFT) is a bidirectional process required for assembly and maintenance of cilia and flagella. Kinesin-2 is the anterograde IFT motor, and Dhc1b/Dhc2 drives retrograde IFT. To understand how either motor interacts with the IFT particle or how their activities might be coordinated, we characterized a ts mutation in the Chlamydomonas gene encoding KAP, the nonmotor subunit of Kinesin-2. The fla3-1 mutation is an amino acid substitution in a conserved C-terminal domain. fla3-1 strains assemble flagella at 21 degrees C, but cannot maintain them at 33 degrees C. Although the Kinesin-2 complex is present at both 21 and 33 degrees C, the fla3-1 Kinesin-2 complex is not efficiently targeted to or retained in the basal body region or flagella. Video-enhanced DIC microscopy of fla3-1 cells shows that the frequency of anterograde IFT particles is significantly reduced. Anterograde particles move at near wild-type velocities, but appear larger and pause more frequently in fla3-1. Transformation with an epitope-tagged KAP gene rescues all of the fla3-1 defects and results in preferential incorporation of tagged KAP complexes into flagella. KAP is therefore required for the localization of Kinesin-2 at the site of flagellar assembly and the efficient transport of anterograde IFT particles within flagella.
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MESH Headings
- Amino Acid Sequence
- Animals
- Binding Sites
- Biological Transport
- Blotting, Southern
- Blotting, Western
- Centromere/ultrastructure
- Chlamydomonas/metabolism
- Cilia/metabolism
- Cloning, Molecular
- DNA, Complementary/metabolism
- Electrophoresis, Polyacrylamide Gel
- Epitopes/chemistry
- Flagella/physiology
- Genetic Linkage
- Kinesins/biosynthesis
- Kinesins/chemistry
- Kinesins/metabolism
- Kinesins/physiology
- Microscopy, Fluorescence
- Microscopy, Video
- Models, Genetic
- Molecular Sequence Data
- Mutation
- Phenotype
- Protein Structure, Tertiary
- RNA/chemistry
- Sequence Homology, Amino Acid
- Temperature
- Time Factors
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Affiliation(s)
- Joshua Mueller
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
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26
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Morris RL, English CN, Lou JE, Dufort FJ, Nordberg J, Terasaki M, Hinkle B. Redistribution of the kinesin-II subunit KAP from cilia to nuclei during the mitotic and ciliogenic cycles in sea urchin embryos. Dev Biol 2004; 274:56-69. [PMID: 15355788 DOI: 10.1016/j.ydbio.2004.06.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2004] [Revised: 06/17/2004] [Accepted: 06/18/2004] [Indexed: 11/25/2022]
Abstract
KAP is the non-motor subunit of the heteromeric plus-end directed microtubule (MT) motor protein kinesin-II essential for normal cilia formation. Studies in Chlamydomonas have demonstrated that kinesin-II drives the anterograde intraflagellar transport (IFT) of protein complexes along ciliary axonemes. We used a green fluorescent protein (GFP) chimera of KAP, KAP-GFP, to monitor movements of this kinesin-II subunit in cells of sea urchin blastulae where cilia are retracted and rebuilt with each mitosis. As expected if involved in IFT, KAP-GFP localized to apical cytoplasm, basal bodies, and cilia and became concentrated on basal bodies of newly forming cilia. Surprisingly, after ciliary retraction early in mitosis, KAP-GFP moved into nuclei before nuclear envelope breakdown, was again present in nuclei after nuclear envelope reformation, and only decreased in nuclei as ciliogenesis reinitiated. Nuclear transport of KAP-GFP could be due to a putative nuclear localization signal and nuclear export signals identified in the sea urchin KAP primary sequence. Our observation of a protein involved in IFT being imported into the nucleus after ciliary retraction and again after nuclear envelope reformation suggests KAP115 may serve as a signal to the nucleus to reinitiate cilia formation during sea urchin development.
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Affiliation(s)
- Robert L Morris
- Department of Biology, Wheaton College, Norton, MA 02766, USA.
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27
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Geimer S, Melkonian M. The ultrastructure of the Chlamydomonas reinhardtii basal apparatus: identification of an early marker of radial asymmetry inherent in the basal body. J Cell Sci 2004; 117:2663-74. [PMID: 15138287 DOI: 10.1242/jcs.01120] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The biflagellate unicellular green alga Chlamydomonas reinhardtii is a classic model organism for the analysis of flagella and their organizers, the basal bodies. In this cell, the two flagella-bearing basal bodies, along with two probasal bodies and an array of fibers and microtubules, form a complex organelle called the basal apparatus. The ultrastructure of the basal apparatus was analysed in detail by serial thin-section electron microscopy of isolated cytoskeletons and several newly discovered features are described, including a marker for the rotational asymmetry inherent in the basal bodies and probasal bodies. In addition, the complex three-dimensional basal apparatus ultrastructure is resolved and illustrated, including the attachment sites of all basal apparatus elements to specific microtubular triplets of the basal bodies and probasal bodies. These data will facilitate both the localization of novel basal apparatus proteins and the analysis of mutants and RNA interference cells with only subtle defects in basal apparatus ultrastructure. The early harbinger of radial asymmetry described here could play a crucial role during basal body maturation by orienting the asymmetric attachment of the various associated fibers and therefore might define the orientation of the basal bodies and, ultimately, the direction of flagellar beating.
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Affiliation(s)
- Stefan Geimer
- Botanisches Institut, Universität zu Köln, Gyrhofstrasse 15, 50931 Köln, Germany.
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28
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Qin H, Diener DR, Geimer S, Cole DG, Rosenbaum JL. Intraflagellar transport (IFT) cargo: IFT transports flagellar precursors to the tip and turnover products to the cell body. ACTA ACUST UNITED AC 2004; 164:255-66. [PMID: 14718520 PMCID: PMC2172340 DOI: 10.1083/jcb.200308132] [Citation(s) in RCA: 270] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Intraflagellar transport (IFT) is the bidirectional movement of multisubunit protein particles along axonemal microtubules and is required for assembly and maintenance of eukaryotic flagella and cilia. One posited role of IFT is to transport flagellar precursors to the flagellar tip for assembly. Here, we examine radial spokes, axonemal subunits consisting of 22 polypeptides, as potential cargo for IFT. Radial spokes were found to be partially assembled in the cell body, before being transported to the flagellar tip by anterograde IFT. Fully assembled radial spokes, detached from axonemal microtubules during flagellar breakdown or turnover, are removed from flagella by retrograde IFT. Interactions between IFT particles, motors, radial spokes, and other axonemal proteins were verified by coimmunoprecipitation of these proteins from the soluble fraction of Chlamydomonas flagella. These studies indicate that one of the main roles of IFT in flagellar assembly and maintenance is to transport axonemal proteins in and out of the flagellum.
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Affiliation(s)
- Hongmin Qin
- MCDB Dept., Yale University, New Haven, CT 06520, USA
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29
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Abstract
First discovered in the green alga, Chlamydomonas, intraflagellar transport (IFT) is the bidirectional movement of protein particles along the length of eukaryotic cilia and flagella. Composed of approximately 16 different proteins, IFT particles are moved out to the distal tip of the organelle by kinesin-II and are brought back to the cell body by cytoplasmic dynein 1b. Mutant analysis of the IFT motor and particle proteins using diverse organisms has revealed a conserved and essential role for IFT in the assembly and maintenance of cilia and flagella. IFT is thought to mediate this assembly through the delivery of axonemal precursors out to the distal tip of the growing organelle. Consistent with this model, the IFT particle proteins are rich in protein-protein binding motifs, suggesting that the particles may act as scaffolds for the binding of multiple cargoes. With most of the IFT proteins now identified at the level of the gene, this review will briefly examine both the structure and function of the IFT machinery of Chlamydomonas reinhardtii.
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Affiliation(s)
- Douglas G Cole
- Department of Microbiology, Molecular Biology and Biochemistry, University of Idaho, Moscow, Idaho, 83844-3052, USA.
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Pan J, Misamore MJ, Wang Q, Snell WJ. Protein transport and signal transduction during fertilization in chlamydomonas. Traffic 2003; 4:452-9. [PMID: 12795690 DOI: 10.1034/j.1600-0854.2003.00105.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Fertilization in Chlamydomonas begins with flagellar adhesion between mating type plus and mating type minus gametes and is consummated within minutes by zygote formation. Once fusion occurs, the newly merged gametes cease existence as distinct entities, and the diploid zygote immediately initiates transcription of zygote-specific genes. Accomplishing fertilization within such a short time requires the rapid and signaled movement of pre-existing membrane and cytoplasmic proteins between and within several cellular compartments. Generation within the adhering flagella of the initial signals for protein movement, as well as movement itself of at least one cytoplasmic protein from the cell body to the flagella, depend on the microtubule motor, kinesin-II and presumably on intraflagellar transport (IFT). Adhesion and fusion of the two gametes depend on a second translocation event, the movement of an adhesion/fusion protein onto the surface of a rapidly elongating, microvillous-like fusion organelle. Finally, the merging of the two separate gametes, each containing sex-specific proteins, into a single cell allows the formerly separate proteins to form new interactions that regulate zygote development. Two proteins - a nuclease and a homeodomain protein - which were present only in the plus gamete, are 'delivered' to the cytoplasm of the zygote during gamete fusion. The nuclease is selectively imported into the minus chloroplast, where it degrades the chloroplast DNA, thereby ensuring uniparental inheritance of plus chloroplast traits. The homeodomain protein binds with an as yet unidentified protein delivered by the minus gamete, and the new complex activates transcription of zygote-specific genes.
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Affiliation(s)
- Junmin Pan
- Department of Cell Biology, University of Texas South-western Medical Center, Dallas, Texas 75390-9039, USA
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Abstract
The long-standing interest in centrioles and basal bodies stems from the evolutionary conservation of their structural design and from their dual mode of assembly (templated versus de novo), revealed by electron microscopic studies nearly four decades ago and unique for a subcellular organelle. Molecular dissection of the assembly pathway during the past few years has recently progressed, essentially through direct and reverse genetic approaches. These studies revealed essential roles for centrins and the gamma-, delta-, epsilon - and eta-tubulins in assembly or as specific signals for centriole duplication. Identification of further components of basal bodies and centrioles might help to unravel the two assembly pathways and their regulation.
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Affiliation(s)
- Janine Beisson
- Centre de Génétique Moléculaire, Centre National de La Recherche Scientifique, 91190 Gif-sur-Yvette, France.
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32
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Abstract
Intraflagellar transport involves the movement of large protein particles along ciliary microtubules and is required for the assembly and maintenance of eukaryotic cilia and flagella. Intraflagellar-transport defects in the mouse cause a range of diseases including polycystic kidney disease, retinal degeneration and the laterality abnormality situs inversus, highlighting the important role that motile, sensory and primary cilia play in vertebrates.
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Affiliation(s)
- Gregory J Pazour
- Dept Cell Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
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33
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Abstract
Eukaryotic cilia and flagella, including primary cilia and sensory cilia, are highly conserved organelles that project from the surfaces of many cells. The assembly and maintenance of these nearly ubiquitous structures are dependent on a transport system--known as 'intraflagellar transport' (IFT)--which moves non-membrane-bound particles from the cell body out to the tip of the cilium or flagellum, and then returns them to the cell body. Recent results indicate that defects in IFT might be a primary cause of some human diseases.
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Affiliation(s)
- Joel L Rosenbaum
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520, USA
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Matsuura K, Lefebvre PA, Kamiya R, Hirono M. Kinesin-II is not essential for mitosis and cell growth in Chlamydomonas. CELL MOTILITY AND THE CYTOSKELETON 2002; 52:195-201. [PMID: 12112134 DOI: 10.1002/cm.10051] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The FLA10 gene product (Fla10p) in Chlamydomonas, a heterotrimeric kinesin-II, plays a crucial role in flagellar assembly as a motor protein driving intraflagellar transport. This protein has also been suggested to play a role in mitosis based on its localization to mitotic spindle. A role for Fla10p in mitosis has been difficult to test because to date only conditional (temperature-sensitive) mutant alleles were available, and it is not known whether these retain residual function for mitosis at the non-permissive temperature. In this report, we describe a null allele of fla10 produced by insertional mutagenesis. This mutant does not assemble flagella, but proliferates at a rate identical to that of wild type cells. Observation of microtubule organization in the cell body revealed that normal mitotic spindles are formed in dividing mutant cells. Thus, we conclude that FLA10 kinesin plays no significant roles in mitosis.
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Affiliation(s)
- Kumi Matsuura
- Department of Biological Sciences, University of Tokyo, Tokyo, Japan
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35
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Deane JA, Cole DG, Seeley ES, Diener DR, Rosenbaum JL. Localization of intraflagellar transport protein IFT52 identifies basal body transitional fibers as the docking site for IFT particles. Curr Biol 2001; 11:1586-90. [PMID: 11676918 DOI: 10.1016/s0960-9822(01)00484-5] [Citation(s) in RCA: 307] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Intraflagellar transport (IFT) is a motility in which particles composed of at least 17 polypeptides move underneath the flagellar membrane. Anterograde (outward) and retrograde (inward) movements of these IFT particles are mediated by FLA10 kinesin-II and cytoplasmic dynein DHC1b, respectively. Mutations affecting IFT particle polypeptides or motors result in the inability to assemble flagella. IFT particles and the motors moving them are located principally around the basal bodies as well as in the flagella. Here, we clone the cDNA encoding one of the IFT particle proteins, IFT52, and show by immunofluorescence that while some IFT52 is in the flagella, the majority is found in two horseshoe-shaped rings around the basal bodies. Immunoelectron microscopy indicates that IFT52 is associated with the periphery of the transitional fibers, which extend from the distal portion of the basal body to the cell membrane and demarcate the entrance to the flagellar compartment. This localization suggests that the transitional fibers form a docking complex for the IFT particles destined for the flagellum. Finally, the flagellaless mutant bld1 completely lacks IFT52 due to a deletion in the gene encoding IFT52.
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Affiliation(s)
- J A Deane
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA
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36
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Harris EH. CHLAMYDOMONAS AS A MODEL ORGANISM. ANNUAL REVIEW OF PLANT PHYSIOLOGY AND PLANT MOLECULAR BIOLOGY 2001; 52:363-406. [PMID: 11337403 DOI: 10.1146/annurev.arplant.52.1.363] [Citation(s) in RCA: 427] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The unicellular green alga Chlamydomonas offers a simple life cycle, easy isolation of mutants, and a growing array of tools and techniques for molecular genetic studies. Among the principal areas of current investigation using this model system are flagellar structure and function, genetics of basal bodies (centrioles), chloroplast biogenesis, photosynthesis, light perception, cell-cell recognition, and cell cycle control. A genome project has begun with compilation of expressed sequence tag data and gene expression studies and will lead to a complete genome sequence. Resources available to the research community include wild-type and mutant strains, plasmid constructs for transformation studies, and a comprehensive on-line database.
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Affiliation(s)
- Elizabeth H Harris
- Developmental, Cell and Molecular Biology Group, Biology Department, Duke University, Durham, North Carolina 27708-1000; e-mail:
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Marshall WF, Vucica Y, Rosenbaum JL. Kinetics and regulation of de novo centriole assembly. Implications for the mechanism of centriole duplication. Curr Biol 2001; 11:308-17. [PMID: 11267867 DOI: 10.1016/s0960-9822(01)00094-x] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Centriole duplication is a key step in the cell cycle whose mechanism is completely unknown. Why new centrioles always form next to preexisting ones is a fundamental question. The simplest model is that preexisting centrioles nucleate the assembly of new centrioles, and that although centrioles can in some cases form de novo without this nucleation, the de novo assembly mechanism should be too slow to compete with normal duplication in order to maintain fidelity of centriole duplication. RESULTS We have measured the rate of de novo centriole assembly in vegetatively dividing cells that normally always contain centrioles. By using mutants of Chlamydomonas that are defective in centriole segregation, we obtained viable centrioleless cells that continue to divide, and find that within a single generation, 50% of these cells reacquire new centrioles by de novo assembly. This suggests that the rate of de novo assembly is approximately half the rate of templated duplication. A mutation in the VFL3 gene causes a complete loss of the templated assembly pathway without eliminating de novo assembly. A mutation in the centrin gene also reduced the rate of templated assembly. CONCLUSIONS These results suggest that there are two pathways for centriole assembly, namely a templated pathway that requires preexisting centrioles to nucleate new centriole assembly, and a de novo assembly pathway that is normally turned off when centrioles are present.
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Affiliation(s)
- W F Marshall
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA.
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Henson JH, Cole DG, Roesener CD, Capuano S, Mendola RJ, Scholey JM. The heterotrimeric motor protein kinesin-II localizes to the midpiece and flagellum of sea urchin and sand dollar sperm. CELL MOTILITY AND THE CYTOSKELETON 2000; 38:29-37. [PMID: 9295139 DOI: 10.1002/(sici)1097-0169(1997)38:1<29::aid-cm4>3.0.co;2-c] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have utilized immunoblotting and light microscopic immunofluorescent staining methods to examine the expression and localization of sea urchin kinesin-II, a heterotrimeric plus end-directed microtubule motor protein (previously referred to as KRP(85/95)), in sea urchin and sand dollar sperm. We demonstrate the presence of the 85 K and 115 K subunits of kinesin-II in sperm and localize these proteins to the sperm flagella and midpiece. The kinesin-II localization pattern is punctate and discontinuous, and in the flagella it is quite distinct from the continuous labeling present in sperm labeled with anti-flagellar dynein. The kinesin-II staining is largely insensitive to prefixation detergent extraction, suggesting that it is not associated with membranous elements in the sperm. In the midpiece the kinesin-II staining is similar to the pattern present in sperm labeled with an anti-centrosomal antibody. To our knowledge, this is the first localization of kinesin-like proteins in mature sperm and corroborates the recent identification and localization of kinesin-like proteins in the flagella and basal body of the unicellular green alga Chlamydomonas. We hypothesize that kinesin-II in the sperm may play functional roles in intraflagellar transport and/or the formation of flagella during spermatogenesis.
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Affiliation(s)
- J H Henson
- Department of Biology, Dickinson College, Carlisle, Pennsylvania 17013, USA.
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Abstract
The length of eukaryotic cilia and flagella depends on the cell cycle-regulated assembly and disassembly of at least 9 doublet and 2 central microtubules, their associated proteins, and the surrounding membrane. In light-synchronized Chlamydomonas cells, flagella assembled to 10-14 microm in length near the beginning of the light period and they disassembled prior to cell division, during the dark period. Flagella on light-synchronized pf18 Chlamydomonas mutants grew to 10-12 microm near the beginning of the light period but shortened by 50% or more by the end of the light period. Flagellar length was cell-cycle regulated: when flagella were amputated at various times during the light period, new flagella regenerated to the lengths of control cells at that time of the light cycle. The later in the cycle pf18 cells were deflagellated, the shorter were the regenerated flagella. Flagellar shortening was not affected, in either pf18 or wild-type (wt) cells, by inhibitors of protein synthesis or of microtubule assembly, so flagellar length cannot depend on protein turnover. Shortening in pf18 was attenuated by Li+, which stimulated flagellar growth in wt cells, by red light, by protein kinase inhibitors, and by the Ca2+ channel blockers La3+ and Cd2+. Shortening was increased by cAMP, Na+, K+, and EGTA. Ca2+-CAM blockers did not affect pf18 shortening but they increased shortening in wt and fa1 cells. We propose that flagellar length is regulated by a signal transduction pathway that is sensitive to Ca2+ levels and red light.
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Affiliation(s)
- J Tuxhorn
- Department of Biochemistry, Cell, and Molecular Biology, University of Kansas, Lawrence 66045, USA
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40
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Geimer S, Teltenkötter A, Plessmann U, Weber K, Lechtreck KF. Purification and characterization of basal apparatuses from a flagellate green alga. CELL MOTILITY AND THE CYTOSKELETON 2000; 37:72-85. [PMID: 9142440 DOI: 10.1002/(sici)1097-0169(1997)37:1<72::aid-cm7>3.0.co;2-j] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Basal apparatuses consisting of two basal bodies and several attached fibers were isolated from the naked green flagellate Spermatozopsis similis by detergent extraction and mechanical disintegration. Sucrose density centrifugation yielded highly enriched basal apparatuses as shown by electron microscopy. SDS-PAGE revealed the absence of histones, indicating the removal of nuclear contaminations from the isolated basal apparatuses. A mass spectrometric analysis of the carboxyterminal peptides of alpha tubulin documented detyrosination and glutamylation as posttranslational modifications and showed that some 5% of the alpha tubulin carries a polyglutamyl side chain which can reach at least 17 residues in length. Monoclonal antibodies raised against the purified basal apparatuses were used to characterize novel components in the basal apparatus. A 210-kD component identified by mAB BAS (basal apparatus of Spermatozopsis) 1.4 was localized in the flagellar transitional region by immunogold electron microscopy. Antibody BAS 16.4 reacted with two high molecular weight bands (approximately 265 and 240 kD) in Western blotting and decorated a fiber attached to the proximal end of the basal bodies. Immunofluorescence staining of isolated cytoskeletons with these mABs demonstrated that the antigens are also present in the basal apparatuses of Chlamydomonas reinhardtii and Dunahella bioculata. These antibodies are useful tools for the molecular cloning of components from the basal apparatus.
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Affiliation(s)
- S Geimer
- Botanisches Institut, Universität zu Köln, Cologne, Germany
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41
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Marszalek JR, Goldstein LS. Understanding the functions of kinesin-II. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1496:142-50. [PMID: 10722883 DOI: 10.1016/s0167-4889(00)00015-x] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Species ranging from Chlamydomonas to humans possess the heterotrimeric kinesin-II holoenzyme composed of two different motor subunits and one non-motor accessory subunit. An important function of kinesin-II is that it transports the components needed for the construction and maintenance of cilia and flagella from the site of synthesis in the cell body to the site of growth at the distal tip. Recent work suggests that kinesin-II does not directly interact with these components, but rather via a large protein complex, which has been termed a raft (intraflagellar transport (IFT)). While ciliary transport is the best-established function for kinesin-II, evidence has been reported for possible roles in neuronal transport, melanosome transport, the secretory pathway and during mitosis.
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Affiliation(s)
- J R Marszalek
- Program in Biomedical Sciences, Division of Cellular and Molecular Medicine, Rm. 334, Department of Pharmacology, Howard Hughes Medical Institute, UCSD School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0683, USA
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Goldstein LS, Philp AV. The road less traveled: emerging principles of kinesin motor utilization. Annu Rev Cell Dev Biol 1999; 15:141-83. [PMID: 10611960 DOI: 10.1146/annurev.cellbio.15.1.141] [Citation(s) in RCA: 211] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Proteins of the kinesin superfamily utilize a conserved catalytic motor domain to generate movements in a wide variety of cellular processes. In this review, we discuss the rapid expansion in our understanding of how eukaryotic cells take advantage of these proteins to generate force and movement in diverse functional contexts. We summarize several recent examples revealing that the simplest view of a kinesin motor protein binding to and translocating a cargo along a microtubule track is inadequate. In fact, this paradigm captures only a small subset of the many ways in which cells harness force production of the generation of intracellular movements and functions. We also highlight several situations where the catalytic kinesin motor domain may not be used to generate movement, but instead may be used in other biochemical and functional contexts. Finally, we review some recent ideas about kinesin motor regulation, redundancy, and cargo attachment strategies.
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Affiliation(s)
- L S Goldstein
- Howard Hughes Medical Institute, Department of Pharmacology, University of California San Diego, La Jolla 92093-0683, USA.
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43
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Whitehead JL, Wang SY, Bost-Usinger L, Hoang E, Frazer KA, Burnside B. Photoreceptor localization of the KIF3A and KIF3B subunits of the heterotrimeric microtubule motor kinesin II in vertebrate retina. Exp Eye Res 1999; 69:491-503. [PMID: 10548469 DOI: 10.1006/exer.1999.0724] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The heterotrimeric microtubule motor kinesin II has been shown to be required for morphogenesis and maintenance of both motile flagella and immotile sensory cilia. Recently, we showed that the KIF3A subunit of kinesin II is concentrated in the inner segment and connecting cilium of fish photoreceptors. Here we report the gene structure of human KIF3A (HsKIF3A) and describe its localization in human and monkey retina. We also describe the localization of both KIF3A and KIF3B kinesin II subunits in Xenopus retina. Using a portion of HsKIF3A we had amplified from adult human retinal cDNA, we found by a GenBank database search that an identical sequence had already been obtained by the Human Genome Center at Lawrence Berkeley National Laboratories in a direct sequencing analysis of 680 kb of human chromosome 5q31. By comparing the genomic sequence of HsKIF3A to the open reading frame (ORF) of the highly homologous mouse Kif3A, we determined that the HsKIF3A gene has 17 exons and an ORF of approximately 2.1 kb, predicting a protein of 80.3 kDa. Antibodies against sea urchin KRP85, a KIF3A homologue, bound to a single band of approximately 85 kDa in immunoblots of total retina protein from human, monkey and Xenopus. In these same samples, a single band of approximately 95 kDa is recognized by antibodies against Xklp3, a Xenopus KIF3B homologue. In sections of Xenopus retina, both antibodies strongly labelled photoreceptor inner segments and the outer limiting membrane. Both antibodies also labelled photoreceptor axonemes. The axonemal localization of kinesin II subunits suggests that kinesin II may play a role in transport of materials from the photoreceptor cell body to the outer segment.
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Affiliation(s)
- J L Whitehead
- Department of Molecular and Cell Biology, University of California, 335 Life Sciences Addition, Berkeley, CA, 94720-3200, USA
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Ray K, Perez SE, Yang Z, Xu J, Ritchings BW, Steller H, Goldstein LS. Kinesin-II is required for axonal transport of choline acetyltransferase in Drosophila. J Cell Biol 1999; 147:507-18. [PMID: 10545496 PMCID: PMC2151187 DOI: 10.1083/jcb.147.3.507] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
KLP64D and KLP68D are members of the kinesin-II family of proteins in Drosophila. Immunostaining for KLP68D and ribonucleic acid in situ hybridization for KLP64D demonstrated their preferential expression in cholinergic neurons. KLP68D was also found to accumulate in cholinergic neurons in axonal obstructions caused by the loss of kinesin light chain. Mutations in the KLP64D gene cause uncoordinated sluggish movement and death, and reduce transport of choline acetyltransferase from cell bodies to the synapse. The inviability of KLP64D mutations can be rescued by expression of mammalian KIF3A. Together, these data suggest that kinesin-II is required for the axonal transport of a soluble enzyme, choline acetyltransferase, in a specific subset of neurons in Drosophila. Furthermore, the data lead to the conclusion that the cargo transport requirements of different classes of neurons may lead to upregulation of specific pathways of axonal transport.
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Affiliation(s)
- Krishanu Ray
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Department of Pharmacology, University of California, San Diego, La Jolla, California 92093-0683
| | - Sharon E. Perez
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Zhaohuai Yang
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Department of Pharmacology, University of California, San Diego, La Jolla, California 92093-0683
| | - Jenny Xu
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Department of Pharmacology, University of California, San Diego, La Jolla, California 92093-0683
| | - Bruce W. Ritchings
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Department of Pharmacology, University of California, San Diego, La Jolla, California 92093-0683
| | - Hermann Steller
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Lawrence S.B. Goldstein
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Department of Pharmacology, University of California, San Diego, La Jolla, California 92093-0683
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Brown JM, Marsala C, Kosoy R, Gaertig J. Kinesin-II is preferentially targeted to assembling cilia and is required for ciliogenesis and normal cytokinesis in Tetrahymena. Mol Biol Cell 1999; 10:3081-96. [PMID: 10512852 PMCID: PMC25561 DOI: 10.1091/mbc.10.10.3081] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
We cloned two genes, KIN1 and KIN2, encoding kinesin-II homologues from the ciliate Tetrahymena thermophila and constructed strains lacking either KIN1 or KIN2 or both genes. Cells with a single disruption of either gene showed partly overlapping sets of defects in cell growth, motility, ciliary assembly, and thermoresistance. Deletion of both genes resulted in loss of cilia and arrests in cytokinesis. Mutant cells were unable to assemble new cilia or to maintain preexisting cilia. Double knockout cells were not viable on a standard medium but could be grown on a modified medium on which growth does not depend on phagocytosis. Double knockout cells could be rescued by transformation with a gene encoding an epitope-tagged Kin1p. In growing cells, epitope-tagged Kin1p preferentially accumulated in cilia undergoing active assembly. Kin1p was also detected in the cell body but did not show any association with the cleavage furrow. The cell division arrests observed in kinesin-II knockout cells appear to be induced by the loss of cilia and resulting cell paralysis.
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Affiliation(s)
- J M Brown
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602-2607, USA
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46
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Marszalek JR, Ruiz-Lozano P, Roberts E, Chien KR, Goldstein LS. Situs inversus and embryonic ciliary morphogenesis defects in mouse mutants lacking the KIF3A subunit of kinesin-II. Proc Natl Acad Sci U S A 1999; 96:5043-8. [PMID: 10220415 PMCID: PMC21813 DOI: 10.1073/pnas.96.9.5043] [Citation(s) in RCA: 410] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The embryonic cellular events that set the asymmetry of the genetic control circuit controlling left-right (L-R) axis determination in mammals are poorly understood. New insight into this problem was obtained by analyzing mouse mutants lacking the KIF3A motor subunit of the kinesin-II motor complex. Embryos lacking KIF3A die at 10 days postcoitum, exhibit randomized establishment of L-R asymmetry, and display numerous structural abnormalities. The earliest detectable abnormality in KIF3A mutant embryos is found at day 7.5, where scanning electron microscopy reveals loss of cilia ordinarily present on cells of the wild-type embryonic node, which is thought to play an important role in setting the initial L-R asymmetry. This cellular phenotype is observed before the earliest reported time of asymmetric expression of markers of the L-R signaling pathway. These observations demonstrate that the kinesin-based transport pathway needed for flagellar and ciliary morphogenesis is conserved from Chlamydomonas to mammals and support the view that embryonic cilia play a role in the earliest cellular determinative events establishing L-R asymmetry.
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Affiliation(s)
- J R Marszalek
- Division of Cellular and Molecular Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA
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47
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Porter ME, Bower R, Knott JA, Byrd P, Dentler W. Cytoplasmic dynein heavy chain 1b is required for flagellar assembly in Chlamydomonas. Mol Biol Cell 1999; 10:693-712. [PMID: 10069812 PMCID: PMC25196 DOI: 10.1091/mbc.10.3.693] [Citation(s) in RCA: 258] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
A second cytoplasmic dynein heavy chain (cDhc) has recently been identified in several organisms, and its expression pattern is consistent with a possible role in axoneme assembly. We have used a genetic approach to ask whether cDhc1b is involved in flagellar assembly in Chlamydomonas. Using a modified PCR protocol, we recovered two cDhc sequences distinct from the axonemal Dhc sequences identified previously. cDhc1a is closely related to the major cytoplasmic Dhc, whereas cDhc1b is closely related to the minor cDhc isoform identified in sea urchins, Caenorhabditis elegans, and Tetrahymena. The Chlamydomonas cDhc1b transcript is a low-abundance mRNA whose expression is enhanced by deflagellation. To determine its role in flagellar assembly, we screened a collection of stumpy flagellar (stf) mutants generated by insertional mutagenesis and identified two strains in which portions of the cDhc1b gene have been deleted. The two mutants assemble short flagellar stumps (<1-2 micrometer) filled with aberrant microtubules, raft-like particles, and other amorphous material. The results indicate that cDhc1b is involved in the transport of components required for flagellar assembly in Chlamydomonas.
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Affiliation(s)
- M E Porter
- Department of Cell Biology and Neuroanatomy, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
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48
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Affiliation(s)
- J L Rosenbaum
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8103, USA.
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Signor D, Wedaman KP, Rose LS, Scholey JM. Two heteromeric kinesin complexes in chemosensory neurons and sensory cilia of Caenorhabditis elegans. Mol Biol Cell 1999; 10:345-60. [PMID: 9950681 PMCID: PMC25173 DOI: 10.1091/mbc.10.2.345] [Citation(s) in RCA: 120] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/1998] [Accepted: 11/23/1998] [Indexed: 11/11/2022] Open
Abstract
Chemosensation in the nervous system of the nematode Caenorhabditis elegans depends on sensory cilia, whose assembly and maintenance requires the transport of components such as axonemal proteins and signal transduction machinery to their site of incorporation into ciliary structures. Members of the heteromeric kinesin family of microtubule motors are prime candidates for playing key roles in these transport events. Here we describe the molecular characterization and partial purification of two heteromeric kinesin complexes from C. elegans, heterotrimeric CeKinesin-II and dimeric CeOsm-3. Transgenic worms expressing green fluorescent protein driven by endogenous heteromeric kinesin promoters reveal that both CeKinesin-II and CeOsm-3 are expressed in amphid, inner labial, and phasmid chemosensory neurons. Additionally, immunolocalization experiments on fixed worms show an intense concentration of CeKinesin-II and CeOsm-3 polypeptides in the ciliated endings of these chemosensory neurons and a punctate localization pattern in the corresponding cell bodies and dendrites. These results, together with the phenotypes of known mutants in the pathway of sensory ciliary assembly, suggest that CeKinesin-II and CeOsm-3 drive the transport of ciliary components required for sequential steps in the assembly of chemosensory cilia.
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Affiliation(s)
- D Signor
- Section of Molecular and Cellular Biology, University of California at Davis, Davis, California 95616, USA
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