1
|
Rabiasz A, Ziętkiewicz E. Schmidtea mediterranea as a Model Organism to Study the Molecular Background of Human Motile Ciliopathies. Int J Mol Sci 2023; 24:ijms24054472. [PMID: 36901899 PMCID: PMC10002865 DOI: 10.3390/ijms24054472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 03/12/2023] Open
Abstract
Cilia and flagella are evolutionarily conserved organelles that form protrusions on the surface of many growth-arrested or differentiated eukaryotic cells. Due to the structural and functional differences, cilia can be roughly classified as motile and non-motile (primary). Genetically determined dysfunction of motile cilia is the basis of primary ciliary dyskinesia (PCD), a heterogeneous ciliopathy affecting respiratory airways, fertility, and laterality. In the face of the still incomplete knowledge of PCD genetics and phenotype-genotype relations in PCD and the spectrum of PCD-like diseases, a continuous search for new causative genes is required. The use of model organisms has been a great part of the advances in understanding molecular mechanisms and the genetic basis of human diseases; the PCD spectrum is not different in this respect. The planarian model (Schmidtea mediterranea) has been intensely used to study regeneration processes, and-in the context of cilia-their evolution, assembly, and role in cell signaling. However, relatively little attention has been paid to the use of this simple and accessible model for studying the genetics of PCD and related diseases. The recent rapid development of the available planarian databases with detailed genomic and functional annotations prompted us to review the potential of the S. mediterranea model for studying human motile ciliopathies.
Collapse
|
2
|
Kaida A, Iwakuma T. Regulation of p53 and Cancer Signaling by Heat Shock Protein 40/J-Domain Protein Family Members. Int J Mol Sci 2021; 22:13527. [PMID: 34948322 PMCID: PMC8706882 DOI: 10.3390/ijms222413527] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 12/27/2022] Open
Abstract
Heat shock proteins (HSPs) are molecular chaperones that assist diverse cellular activities including protein folding, intracellular transportation, assembly or disassembly of protein complexes, and stabilization or degradation of misfolded or aggregated proteins. HSP40, also known as J-domain proteins (JDPs), is the largest family with over fifty members and contains highly conserved J domains responsible for binding to HSP70 and stimulation of the ATPase activity as a co-chaperone. Tumor suppressor p53 (p53), the most frequently mutated gene in human cancers, is one of the proteins that functionally interact with HSP40/JDPs. The majority of p53 mutations are missense mutations, resulting in acquirement of unexpected oncogenic activities, referred to as gain of function (GOF), in addition to loss of the tumor suppressive function. Moreover, stability and levels of wild-type p53 (wtp53) and mutant p53 (mutp53) are crucial for their tumor suppressive and oncogenic activities, respectively. However, the regulatory mechanisms of wtp53 and mutp53 are not fully understood. Accumulating reports demonstrate regulation of wtp53 and mutp53 levels and/or activities by HSP40/JDPs. Here, we summarize updated knowledge related to the link of HSP40/JDPs with p53 and cancer signaling to improve our understanding of the regulation of tumor suppressive wtp53 and oncogenic mutp53 GOF activities.
Collapse
Affiliation(s)
- Atsushi Kaida
- Department of Oral Radiation Oncology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8510, Japan;
- Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Tomoo Iwakuma
- Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
- Department of Pediatrics, Children’s Mercy Research Institute, Kansas City, MO 64108, USA
| |
Collapse
|
3
|
Piette BL, Alerasool N, Lin ZY, Lacoste J, Lam MHY, Qian WW, Tran S, Larsen B, Campos E, Peng J, Gingras AC, Taipale M. Comprehensive interactome profiling of the human Hsp70 network highlights functional differentiation of J domains. Mol Cell 2021; 81:2549-2565.e8. [PMID: 33957083 DOI: 10.1016/j.molcel.2021.04.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 04/13/2021] [Accepted: 04/14/2021] [Indexed: 12/22/2022]
Abstract
Hsp70s comprise a deeply conserved chaperone family that has a central role in maintaining protein homeostasis. In humans, Hsp70 client specificity is provided by 49 different co-factors known as J domain proteins (JDPs). However, the cellular function and client specificity of JDPs have largely remained elusive. We have combined affinity purification-mass spectrometry (AP-MS) and proximity-dependent biotinylation (BioID) to characterize the interactome of all human JDPs and Hsp70s. The resulting network suggests specific functions for many uncharacterized JDPs, and we establish a role of conserved JDPs DNAJC9 and DNAJC27 in histone chaperoning and ciliogenesis, respectively. Unexpectedly, we find that the J domain of DNAJC27 but not of other JDPs can fully replace the function of endogenous DNAJC27, suggesting a previously unappreciated role for J domains themselves in JDP specificity. More broadly, our work expands the role of the Hsp70-regulated proteostasis network and provides a platform for further discovery of JDP-dependent functions.
Collapse
Affiliation(s)
- Benjamin L Piette
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON M5G 1X5, Canada; Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Nader Alerasool
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada; Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Zhen-Yuan Lin
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON M5G 1X5, Canada
| | - Jessica Lacoste
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada; Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Mandy Hiu Yi Lam
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON M5G 1X5, Canada
| | - Wesley Wei Qian
- Department of Computer Science, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Stephanie Tran
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada; Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Brett Larsen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON M5G 1X5, Canada
| | - Eric Campos
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada; Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Jian Peng
- Department of Computer Science, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Anne-Claude Gingras
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON M5G 1X5, Canada.
| | - Mikko Taipale
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada; Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON M5S 3E1, Canada.
| |
Collapse
|
4
|
Wei W, Jiang C, Yang W, Miao W, Xiong J. Proteomic identification and expression of oral apparatus constituents in cell regeneration of giant ciliate Stentor coeruleus (strain WHEL). Gene 2020; 743:144624. [PMID: 32224274 DOI: 10.1016/j.gene.2020.144624] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/02/2020] [Accepted: 03/24/2020] [Indexed: 11/29/2022]
Abstract
The giant ciliate Stentor coeruleus (S. coeruleus) is a suitable model organism for studying morphogenesis and regeneration at the single-cell level. It contains a prominent structure on the anterior end of the cell, known as the oral apparatus (OA). OA can be induced to shed by urea treatment and then new OA regenerates via a series of defined morphological events and the cell resumes normal feeding activity. We identified OA constituents in S. coeruleus by mass spectrometry. A total of 882 OA-associated proteins were identified; the homologs of 181 of these are known OA constituents in other organisms. The expression pattern of OA-associated genes during regeneration was investigated using single-cell transcriptome sequencing. The expression of most OA-associated genes was high during regeneration, indicating their stable expression after OA shedding. We also identified OA-associated differentially expressed genes that may be involved in regulating OA reconstruction. In summary, this study gives preliminary insight into the molecular basis of OA in S. coeruleus.
Collapse
Affiliation(s)
- Wei Wei
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chuanqi Jiang
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Wentao Yang
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Miao
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; CAS Center for Excellence in Animal Evolution and Genetics, Kunming 650223, China; State Key Laboratory of Freshwater Ecology and Biotechnology of China, Wuhan 430072, China
| | - Jie Xiong
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
| |
Collapse
|
5
|
Rare Human Diseases: Model Organisms in Deciphering the Molecular Basis of Primary Ciliary Dyskinesia. Cells 2019; 8:cells8121614. [PMID: 31835861 PMCID: PMC6952885 DOI: 10.3390/cells8121614] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 12/02/2019] [Accepted: 12/10/2019] [Indexed: 12/17/2022] Open
Abstract
Primary ciliary dyskinesia (PCD) is a recessive heterogeneous disorder of motile cilia, affecting one per 15,000-30,000 individuals; however, the frequency of this disorder is likely underestimated. Even though more than 40 genes are currently associated with PCD, in the case of approximately 30% of patients, the genetic cause of the manifested PCD symptoms remains unknown. Because motile cilia are highly evolutionarily conserved organelles at both the proteomic and ultrastructural levels, analyses in the unicellular and multicellular model organisms can help not only to identify new proteins essential for cilia motility (and thus identify new putative PCD-causative genes), but also to elucidate the function of the proteins encoded by known PCD-causative genes. Consequently, studies involving model organisms can help us to understand the molecular mechanism(s) behind the phenotypic changes observed in the motile cilia of PCD affected patients. Here, we summarize the current state of the art in the genetics and biology of PCD and emphasize the impact of the studies conducted using model organisms on existing knowledge.
Collapse
|
6
|
Li WN, Zhu L, Jia MM, Yin SL, Lu GX, Liu G. Missense mutation in DNAJB13 gene correlated with male fertility in asthenozoospermia. Andrology 2019; 8:299-306. [PMID: 31342671 DOI: 10.1111/andr.12685] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 06/28/2019] [Accepted: 06/28/2019] [Indexed: 11/28/2022]
Abstract
BACKGROUND The most common type of male infertility is asthenospermia. We cloned DnaJ heat shock protein family member B13 (Dnajb13/DNAJB13), a type II HSP40 family member that is highly expressed in the testis. DNAJB13 plays a crucial role in sperm flagellar function. OBJECTIVES The aim of this study was to investigate whether a correlation exists between DNAJB13 and low sperm motility in infertile men. MATERIALS AND METHODS In the present study, we performed a mutation screening of the DNAJB13 gene in 92 idiopathic asthenozoospermia patients and 200 men with normal fertility. Additionally, we used immunoelectron microscopy, co-immunoprecipitation, mass spectrometric detection, indirect immunofluorescence assay, transmission electron microscopy studies, isobaric tags for relative and absolute quantitation, and multiple reaction monitoring studies to analyze changes in DNAJB13 protein. RESULTS A novel c.106T>C mutation of DNAJB13 was present in nearly 10% (9/92) of idiopathic asthenozoospermia patients and was absent in 200 fertile men. A computer-assisted sperm analyzer and transmission electron microscopy analysis using samples from 9 patients with DNAJB13 mutations demonstrated that most spermatozoa were immotile due to sperm tail defects. Multiple reaction monitoring results indicated that DNAJB13 protein levels were reduced after gene mutation. We achieved a pregnancy rate of 100% in 8 patients with DNAJB13 mutations using ICSI. DISCUSSION AND CONCLUSION The DNAJB13 heterozygous variant may affect fertility. ICSI can help these patients with low fertility to father children.
Collapse
Affiliation(s)
- W N Li
- Hunan Guangxiu Hi-tech Life Technology Co., Ltd., Changsha, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, China
| | - L Zhu
- The Xiangtan Central Hospital, Yuhu District, Xiangtan, China
| | - M M Jia
- Shanxi Provincial Maternal and Child Health Care Hospital, Yanta District, Xi'an, China
| | - S L Yin
- Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, China
| | - G X Lu
- Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, China.,The Institute of Reproduction and Stem Cell Engineering, Central South University, Changsha, China
| | - G Liu
- The Institute of Reproduction and Stem Cell Engineering, Central South University, Changsha, China
| |
Collapse
|
7
|
Chen Z, Lee WG. A switching role of hard-uptake nanoparticles in microalgae cell electroporation. Analyst 2019; 144:3581-3589. [PMID: 31065636 DOI: 10.1039/c9an00314b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The microalgal cell wall is a natural barrier that limits the efficiency of gene delivery in algae genetic engineering. Here, we report the role of hard-uptake nanoparticles (huNPs) in microalgae cell electroporation to enhance the delivery of genes in Chlamydomonas reinhardtii. This role can be divided into two categories: (i) a 'transient state' for short-term behavior under confocal visualization and (ii) a 'steady state' for long-term behavior in cell culture. First, the 'transient' role of gene-huNP complexes was investigated after washing for clear confocal imaging to observe the location of huNPs after electroporation. Second, the 'steady-state' role of the gene-huNP complexes was examined after electroporation by transferring cells to a fresh, medium-rich culture environment without washing to obtain a stable cell culture. For selection of the huNPs, we used two types of nanoparticles (NPs, 250 nm and 530 nm) larger than the threshold size of electroporation uptake to avoid unwanted endocytic uptake of NPs. In the transient state, the visualization results indicate that gene-NP (250 nm) complexes were positioned on the cells and helped to deliver more genes than did the 530 nm NPs. In the steady state, the gene-NP (530 nm) complexes helped stably deliver more genes to the cells by precipitation of NPs due to gravity. We believe that these findings illustrate how gene-NP complexes function in microalgae cell electroporation and could help set up a protocol for enhanced microalgae applications associated with NPs such as environmental waste removal and biofuel production.
Collapse
Affiliation(s)
- Zhenzhong Chen
- Department of Mechanical Engineering, Kyung Hee University, Yongin 17104, Republic of Korea.
| | - Won Gu Lee
- Department of Mechanical Engineering, Kyung Hee University, Yongin 17104, Republic of Korea.
| |
Collapse
|
8
|
Zhu X, Poghosyan E, Rezabkova L, Mehall B, Sakakibara H, Hirono M, Kamiya R, Ishikawa T, Yang P. The roles of a flagellar HSP40 ensuring rhythmic beating. Mol Biol Cell 2018; 30:228-241. [PMID: 30427757 PMCID: PMC6589562 DOI: 10.1091/mbc.e18-01-0047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
HSP40s are regarded as cochaperones, perpetually shuttling client polypeptides to HSP70s for refolding. However, many HSP40s that are central for disparate processes diverge from this paradigm. To elucidate the noncanonical mechanisms, we investigated HSP40 in the radial spoke (RS) complex in flagella. Disruption of the gene by the MRC1 transposon in Chlamydomonas resulted in jerky flagella. Traditional electron microscopy, cryo-electron tomography, and sub-tomogram analysis revealed RSs of various altered morphologies that, unexpectedly, differed between the two RS species. This indicates that HSP40 locks the RS into a functionally rigid conformation, facilitating its interactions with the adjacent central pair apparatus for transducing locally varied mechanical feedback, which permits rhythmic beating. Missing HSP40, like missing RSs, could be restored in a tip-to-base direction when HSP40 mutants fused with a HSP40 donor cell. However, without concomitant de novo RS assembly, the repair was exceedingly slow, suggesting HSP40/RS-coupled intraflagellar trafficking and assembly. Biochemical analysis and modeling uncovered spoke HSP40’s cochaperone traits. On the basis of our data, we propose that HSP40 accompanies its client RS precursor when traveling to the flagellar tip. Upon arrival, both refold in concert to assemble into the mature configuration. HSP40’s roles in chaperoning and structural maintenance shed new light on its versatility and flagellar biology.
Collapse
Affiliation(s)
- Xiaoyan Zhu
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233
| | - Emiliya Poghosyan
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Lenka Rezabkova
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Bridget Mehall
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233
| | - Hitoshi Sakakibara
- National Institute of Information and Communications Technology (NICT), Advanced ICT Research Institute, Hyogo 651-2492, Japan
| | - Masafumi Hirono
- Department of Frontier Bioscience, Hosei University, Tokyo 184-8584, Japan
| | - Ritsu Kamiya
- Department of Life Science, Faculty of Science, Gakushuin University, Tokyo 171-8588, Japan
| | - Takashi Ishikawa
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Pinfen Yang
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233
| |
Collapse
|
9
|
Han X, Xie H, Wang Y, Zhao C. Radial spoke proteins regulate otolith formation during early zebrafish development. FASEB J 2018; 32:3984-3992. [PMID: 29475374 DOI: 10.1096/fj.201701359r] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Radial spokes are structurally conserved, macromolecular complexes that are essential for the motility of 9 + 2 motile cilia. In Chlamydomonas species, mutations in radial spoke proteins result in ciliary motility defects. However, little is known about the function of radial spoke proteins during embryonic development. Here, we investigated the role of a novel radial spoke protein, leucine-rich repeat containing protein 23 (Lrrc23), during zebrafish embryonic development. Mutations in lrrc23 resulted in a selective otolith formation defect during early ear development. Similar otolith defects were also present in the radial spoke head 3 homolog ( rsph3) and radial spoke head 4 homolog A ( rsph4a) radial spoke mutants. Notably, the radial spoke protein mutations specifically affected ciliary motility in the otic vesicle (OV), whereas motile cilia in other organs functioned normally. Via high-speed video microscopy, we found that motile cilia formation was stochastic and transient in the OV. Importantly, all the motile cilia in the OV beat circularly, in contrast to the planar beating pattern of typical 9 + 2 motile cilia. We identified the key time frame for motile cilia formation during OV development. Finally, we showed that the functions of radial spoke proteins were conserved between zebrafish and Tetrahymena. Together, our results suggest that radial spoke proteins are essential for ciliary motility in the OV and that radial spoke-regulated OV motile cilia represent a unique type of cilia during early zebrafish embryonic development.-Han, X., Xie, H., Wang, Y., Zhao, C. Radial spoke proteins regulate otolith formation during early zebrafish development.
Collapse
Affiliation(s)
- Xiao Han
- Institute of Evolution and Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, China
| | - Haibo Xie
- Institute of Evolution and Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, China
| | - Yadong Wang
- Institute of Evolution and Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, China
| | - Chengtian Zhao
- Institute of Evolution and Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| |
Collapse
|
10
|
Pulido P, Leister D. Novel DNAJ-related proteins in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2018; 217:480-490. [PMID: 29271039 DOI: 10.1111/nph.14827] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Classical DNAJ proteins are co-chaperones that together with HSP70s control protein homeostasis. All three classical types of DNAJ proteins (DNAJA, DNAJB and DNAJC types) possess the J-domain for interaction with HSP70. DNAJA proteins contain, in addition, both the zinc-finger motif and the C-terminal domain which are involved in substrate binding, while DNAJB retains only the latter and DNAJC comprises only the J-domain. There is increasing evidence that some of the activities of DNAJ proteins do not require the J-domain, highlighting the functional significance of the other two domains. Indeed, the so-called DNAJ-like proteins with a degenerate J-domain have been previously coined as DNAJD proteins, and also proteins containing only a DNAJ-like zinc-finger motif appear to be involved in protein homeostasis. Therefore, we propose to extend the classification of DNAJ-related proteins into three different groups. The DNAJD type comprises proteins with a J-like domain only, and has 15 members in Arabidopsis thaliana, whereas proteins of the DNAJE (33 Arabidopsis members) and DNAJF (three Arabidopsis members) types contain a DNAJA-like zinc-finger domain and DNAJA/B-like C-terminal domain, respectively. Here, we provide an overview of the entire repertoire of these proteins in A. thaliana with respect to their physiological function and possible evolutionary origin.
Collapse
Affiliation(s)
- Pablo Pulido
- Plant Molecular Biology, Department Biology I, Ludwig-Maximilians-Universität München, D-82152, Planegg-Martinsried, Germany
- Copenhagen Plant Science Centre, University of Copenhagen, 1871, Frederiksberg C, Denmark
| | - Dario Leister
- Plant Molecular Biology, Department Biology I, Ludwig-Maximilians-Universität München, D-82152, Planegg-Martinsried, Germany
| |
Collapse
|
11
|
Zhu X, Poghosyan E, Gopal R, Liu Y, Ciruelas KS, Maizy Y, Diener DR, King SM, Ishikawa T, Yang P. General and specific promotion of flagellar assembly by a flagellar nucleoside diphosphate kinase. Mol Biol Cell 2017; 28:3029-3042. [PMID: 28877983 PMCID: PMC5662260 DOI: 10.1091/mbc.e17-03-0156] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 08/25/2017] [Accepted: 08/30/2017] [Indexed: 12/20/2022] Open
Abstract
NDK5 promotes assembly of motile cilia and flagella with its structure and protein phosphorylation–related reactions instead of the canonical NDK activity. The novel mechanisms and dominant-negative effect of mutated functional NDK5 reveal the remarkable versatility of a molecular platform that is used in diverse cellular processes. Nucleoside diphosphate kinases (NDKs) play a central role in diverse cellular processes using the canonical NDK activity or alternative mechanisms that remain poorly defined. Our study of dimeric NDK5 in a flagellar motility control complex, the radial spoke (RS), has revealed new modalities. The flagella in Chlamydomonas ndk5 mutant were paralyzed, albeit only deficient in three RS subunits. RS morphology appeared severely changed in averaged cryo-electron tomograms, suggesting that NDK5 is crucial for the intact spokehead formation as well as RS structural stability. Intriguingly, ndk5’s flagella were also short, resembling those of an allelic spoke-less mutant. All ndk5’s phenotypes were rescued by expressions of NDK5 or a mutated NDK5 lacking the canonical kinase activity. Importantly, the mutated NDK5 that appeared fully functional in ndk5 cells elicited a dominant-negative effect in wild-type cells, causing paralyzed short flagella with hypophosphorylated, less abundant, but intact RSs, and accumulated hypophosphorylated NDK5 in the cell body. We propose that NDK5 dimer is an RS structural subunit with an additional mechanism that uses cross-talk between the two NDK monomers to accelerate phosphorylation-related assembly of RSs and entire flagella.
Collapse
Affiliation(s)
- Xiaoyan Zhu
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233
| | - Emiliya Poghosyan
- Biomolecular Research Laboratory, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Radhika Gopal
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233
| | - Yi Liu
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233
| | - Kristine S Ciruelas
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233
| | - Yousif Maizy
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233
| | - Dennis R Diener
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520
| | - Stephen M King
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030-3305
| | - Takashi Ishikawa
- Biomolecular Research Laboratory, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Pinfen Yang
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233
| |
Collapse
|
12
|
Zhu X, Liu Y, Yang P. Radial Spokes-A Snapshot of the Motility Regulation, Assembly, and Evolution of Cilia and Flagella. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a028126. [PMID: 27940518 DOI: 10.1101/cshperspect.a028126] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Propulsive forces generated by cilia and flagella are used in events that are critical for the thriving of diverse eukaryotic organisms in their environments. Despite distinctive strokes and regulations, the majority of them adopt the 9+2 axoneme that is believed to exist in the last eukaryotic common ancestor. Only a few outliers have opted for a simpler format that forsakes the signature radial spokes and the central pair apparatus, although both are unnecessary for force generation or rhythmicity. Extensive evidence has shown that they operate as an integral system for motility control. Recent studies have made remarkable progress on the radial spoke. This review will trace how the new structural, compositional, and evolutional insights pose significant implications on flagella biology and, conversely, ciliopathy.
Collapse
Affiliation(s)
- Xiaoyan Zhu
- The Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53201
| | - Yi Liu
- The Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53201
| | - Pinfen Yang
- The Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53201
| |
Collapse
|
13
|
Mutations in DNAJB13, Encoding an HSP40 Family Member, Cause Primary Ciliary Dyskinesia and Male Infertility. Am J Hum Genet 2016; 99:489-500. [PMID: 27486783 DOI: 10.1016/j.ajhg.2016.06.022] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Accepted: 06/22/2016] [Indexed: 10/21/2022] Open
Abstract
Primary ciliary dyskinesia (PCD) is an autosomal-recessive disease due to functional or ultra-structural defects of motile cilia. Affected individuals display recurrent respiratory-tract infections; most males are infertile as a result of sperm flagellar dysfunction. The great majority of the PCD-associated genes identified so far encode either components of dynein arms (DAs), which are multiprotein-ATPase complexes essential for ciliary motility, or proteins involved in DA assembly. To identify the molecular basis of a PCD phenotype characterized by central complex (CC) defects but normal DA structure, a phenotype found in ∼15% of cases, we performed whole-exome sequencing in a male individual with PCD and unexplained CC defects. This analysis, combined with whole-genome SNP genotyping, identified a homozygous mutation in DNAJB13 (c.833T>G), a gene encoding a HSP40 co-chaperone whose ortholog in the flagellated alga Chlamydomonas localizes to the radial spokes. In vitro studies showed that this missense substitution (p.Met278Arg), which involves a highly conserved residue of several HSP40 family members, leads to protein instability and triggers proteasomal degradation, a result confirmed by the absence of endogenous DNAJB13 in cilia and sperm from this individual. Subsequent DNAJB13 analyses identified another homozygous mutation in a second family; the study of DNAJB13 transcripts obtained from airway cells showed that this mutation (c.68+1G>C) results in a splicing defect consistent with a loss-of-function mutation. Overall, this study, which establishes mutations in DNAJB13 as a cause of PCD, unveils the key role played by DNAJB13 in the proper formation and function of ciliary and flagellar axonemes in humans.
Collapse
|
14
|
Ajit Tamadaddi C, Sahi C. J domain independent functions of J proteins. Cell Stress Chaperones 2016; 21:563-70. [PMID: 27145962 PMCID: PMC4908003 DOI: 10.1007/s12192-016-0697-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 04/04/2016] [Accepted: 04/25/2016] [Indexed: 01/19/2023] Open
Abstract
Heat shock proteins of 40 kDa (Hsp40s), also called J proteins, are obligate partners of Hsp70s. Via their highly conserved and functionally critical J domain, J proteins interact and modulate the activity of their Hsp70 partners. Mutations in the critical residues in the J domain often result in the null phenotype for the J protein in question. However, as more J proteins have been characterized, it is becoming increasingly clear that a significant number of J proteins do not "completely" rely on their J domains to carry out their cellular functions, as previously thought. In some cases, regions outside the highly conserved J domain have become more important making the J domain dispensable for some, if not for all functions of a J protein. This has profound effects on the evolution of such J proteins. Here we present selected examples of J proteins that perform J domain independent functions and discuss this in the context of evolution of J proteins with dispensable J domains and J-like proteins in eukaryotes.
Collapse
Affiliation(s)
- Chetana Ajit Tamadaddi
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India
| | - Chandan Sahi
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India.
| |
Collapse
|
15
|
Harris JA, Liu Y, Yang P, Kner P, Lechtreck KF. Single-particle imaging reveals intraflagellar transport-independent transport and accumulation of EB1 in Chlamydomonas flagella. Mol Biol Cell 2015; 27:295-307. [PMID: 26631555 PMCID: PMC4713132 DOI: 10.1091/mbc.e15-08-0608] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 11/20/2015] [Indexed: 12/20/2022] Open
Abstract
The microtubule (MT) plus-end tracking protein EB1 is present at the tips of cilia and flagella; end-binding protein 1 (EB1) remains at the tip during flagellar shortening and in the absence of intraflagellar transport (IFT), the predominant protein transport system in flagella. To investigate how EB1 accumulates at the flagellar tip, we used in vivo imaging of fluorescent protein-tagged EB1 (EB1-FP) in Chlamydomonas reinhardtii. After photobleaching, the EB1 signal at the flagellar tip recovered within minutes, indicating an exchange with unbleached EB1 entering the flagella from the cell body. EB1 moved independent of IFT trains, and EB1-FP recovery did not require the IFT pathway. Single-particle imaging showed that EB1-FP is highly mobile along the flagellar shaft and displays a markedly reduced mobility near the flagellar tip. Individual EB1-FP particles dwelled for several seconds near the flagellar tip, suggesting the presence of stable EB1 binding sites. In simulations, the two distinct phases of EB1 mobility are sufficient to explain its accumulation at the tip. We propose that proteins uniformly distributed throughout the cytoplasm like EB1 accumulate locally by diffusion and capture; IFT, in contrast, might be required to transport proteins against cellular concentration gradients into or out of cilia.
Collapse
Affiliation(s)
- J Aaron Harris
- Department of Cellular Biology, University of Georgia, Athens, GA 30602
| | - Yi Liu
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233
| | - Pinfen Yang
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233
| | - Peter Kner
- College of Engineering, University of Georgia, Athens, GA 30602
| | - Karl F Lechtreck
- Department of Cellular Biology, University of Georgia, Athens, GA 30602
| |
Collapse
|
16
|
Vasudevan KK, Song K, Alford LM, Sale WS, Dymek EE, Smith EF, Hennessey T, Joachimiak E, Urbanska P, Wloga D, Dentler W, Nicastro D, Gaertig J. FAP206 is a microtubule-docking adapter for ciliary radial spoke 2 and dynein c. Mol Biol Cell 2014; 26:696-710. [PMID: 25540426 PMCID: PMC4325840 DOI: 10.1091/mbc.e14-11-1506] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Radial spokes are conserved macromolecular complexes that are essential for ciliary motility. Little is known about the assembly and functions of the three individual radial spokes, RS1, RS2, and RS3. In Tetrahymena, a conserved ciliary protein, FAP206, docks RS2 and dynein c to the doublet microtubule. Radial spokes are conserved macromolecular complexes that are essential for ciliary motility. A triplet of three radial spokes, RS1, RS2, and RS3, repeats every 96 nm along the doublet microtubules. Each spoke has a distinct base that docks to the doublet and is linked to different inner dynein arms. Little is known about the assembly and functions of individual radial spokes. A knockout of the conserved ciliary protein FAP206 in the ciliate Tetrahymena resulted in slow cell motility. Cryo–electron tomography showed that in the absence of FAP206, the 96-nm repeats lacked RS2 and dynein c. Occasionally, RS2 assembled but lacked both the front prong of its microtubule base and dynein c, whose tail is attached to the front prong. Overexpressed GFP-FAP206 decorated nonciliary microtubules in vivo. Thus FAP206 is likely part of the front prong and docks RS2 and dynein c to the microtubule.
Collapse
Affiliation(s)
| | - Kangkang Song
- Department of Biology, Rosenstiel Center, Brandeis University, Waltham, MA 02454
| | - Lea M Alford
- Department of Cell Biology, Emory University, Atlanta, GA 30303
| | - Winfield S Sale
- Department of Cell Biology, Emory University, Atlanta, GA 30303
| | - Erin E Dymek
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755
| | - Elizabeth F Smith
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755
| | - Todd Hennessey
- Department of Biological Sciences, State University of New York, Buffalo, NY 14260
| | - Ewa Joachimiak
- Department of Cell Biology, Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland Department of Animal Physiology, Faculty of Biology, University of Warsaw, 02-096 Warsaw, Poland
| | - Paulina Urbanska
- Department of Cell Biology, Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland
| | - Dorota Wloga
- Department of Cell Biology, Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland
| | - William Dentler
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045
| | - Daniela Nicastro
- Department of Biology, Rosenstiel Center, Brandeis University, Waltham, MA 02454
| | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, GA 30602
| |
Collapse
|
17
|
Li W, Liu G. DNAJB13, a type II HSP40 family member, localizes to the spermatids and spermatozoa during mouse spermatogenesis. BMC DEVELOPMENTAL BIOLOGY 2014; 14:38. [PMID: 25233908 PMCID: PMC4236558 DOI: 10.1186/s12861-014-0038-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 09/10/2014] [Indexed: 01/25/2023]
Abstract
BACKGROUND Hundreds of HSP40s derived from various species have been identified, of which several proteins are involved in spermatogenesis. DNAJB13 is a type II HSP40/DnaJ protein. In a previous study, we cloned mouse Dnajb13, which is up-regulated in cryptorchidism. To date, however, little is known about the localization and functions of DNAJB13 during spermatogenesis. This study intends to identify the expression pattern of DNAJB13 during mammalian spermatogenesis. RESULTS RT-PCR and western blot revealed that the Dnajb13 gene and DNAJB13 protein were expressed not only in the testis but also in several other ciliated cell-containing tissues like the trachea, lung and oviduct. Quantitative PCR showed that the expression of Dnajb13 mRNA in testis was detectable as early as postnatal week 1, and sharply increased from postnatal week 3. Western blotting and immunohistochemistry determined that the DNAJB13 protein, which was located in the cytoplasm of spermatids and the sperm flagellum, was detectable from postnatal week 4. CONCLUSIONS Based on the spatiotemporal expression observed in the cytoplasm of spermatids and sperm flagella, we suggest that DNAJB13 participates in spermiogenesis and the motility of mature spermatozoa.
Collapse
Affiliation(s)
| | - Gang Liu
- Institute of Reproduction and Stem Cell Engineering, Central South University, Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha 410078, China.
| |
Collapse
|
18
|
Sequence and domain conservation of the coelacanth Hsp40 and Hsp90 chaperones suggests conservation of function. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2013; 322:359-78. [DOI: 10.1002/jez.b.22541] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Revised: 07/13/2013] [Accepted: 08/16/2013] [Indexed: 01/17/2023]
|
19
|
Highly efficient molecular delivery into Chlamydomonas reinhardtii by electroporation. KOREAN J CHEM ENG 2013. [DOI: 10.1007/s11814-013-0098-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
20
|
Sivadas P, Dienes JM, St Maurice M, Meek WD, Yang P. A flagellar A-kinase anchoring protein with two amphipathic helices forms a structural scaffold in the radial spoke complex. ACTA ACUST UNITED AC 2013; 199:639-51. [PMID: 23148234 PMCID: PMC3494852 DOI: 10.1083/jcb.201111042] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Amphipathic helices in the A-kinase anchoring protein RSP3 bind to spoke proteins involved in the assembly and modulation of the flagellar radial spoke complex, expanding the repertoire of these versatile helical protein motifs. A-kinase anchoring proteins (AKAPs) contain an amphipathic helix (AH) that binds the dimerization and docking (D/D) domain, RIIa, in cAMP-dependent protein kinase A (PKA). Many AKAPs were discovered solely based on the AH–RIIa interaction in vitro. An RIIa or a similar Dpy-30 domain is also present in numerous diverged molecules that are implicated in critical processes as diverse as flagellar beating, membrane trafficking, histone methylation, and stem cell differentiation, yet these molecules remain poorly characterized. Here we demonstrate that an AKAP, RSP3, forms a dimeric structural scaffold in the flagellar radial spoke complex, anchoring through two distinct AHs, the RIIa and Dpy-30 domains, in four non-PKA spoke proteins involved in the assembly and modulation of the complex. Interestingly, one AH can bind both RIIa and Dpy-30 domains in vitro. Thus, AHs and D/D domains constitute a versatile yet potentially promiscuous system for localizing various effector mechanisms. These results greatly expand the current concept about anchoring mechanisms and AKAPs.
Collapse
Affiliation(s)
- Priyanka Sivadas
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53201, USA
| | | | | | | | | |
Collapse
|
21
|
DiPetrillo CG, Smith EF. Methods for analysis of calcium/calmodulin signaling in cilia and flagella. Methods Enzymol 2013; 524:37-57. [PMID: 23498733 DOI: 10.1016/b978-0-12-397945-2.00003-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The axonemal microtubules of cilia/flagella act as a scaffold for assembly of the protein complexes that ultimately regulate dynein activity to control the size and shape of ciliary bends. Despite our general understanding of the contribution of microtubule sliding to ciliary and flagellar motility, many questions regarding the regulation of dynein remain unanswered. For example, we know that the second messenger calcium plays an important role in modulating dynein activity in response to extracellular cues, but it remains unclear how calcium-binding proteins anchored to the axoneme contribute to this regulation. Recent work has focused on determining the identity and specific functions of these axonemal calcium-binding proteins. Here, we review our current knowledge of calcium-mediated motility and highlight key experiments that have substantially aided our understanding of calcium signaling within the axoneme.
Collapse
Affiliation(s)
- Christen G DiPetrillo
- Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, USA
| | | |
Collapse
|
22
|
The DPY-30 domain and its flanking sequence mediate the assembly and modulation of flagellar radial spoke complexes. Mol Cell Biol 2012; 32:4012-24. [PMID: 22851692 DOI: 10.1128/mcb.06602-11] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
RIIa is known as the dimerization and docking (D/D) domain of the cyclic AMP (cAMP)-dependent protein kinase. However, numerous molecules, including radial spoke protein 2 (RSP2) in Chlamydomonas flagella, also contain an RIIa or a similar DPY-30 domain. To elucidate new roles of D/D domain-containing proteins, we investigated a panel of RSP2 mutants. An RSP2 mutant had paralyzed flagella defective in RSP2 and multiple subunits near the spokehead. New transgenic strains lacking only the DPY-30 domain in RSP2 were also paralyzed. In contrast, motility was restored in strains that lacked only RSP2's calmodulin-binding C-terminal region. These cells swam normally in dim light but could not maintain typical swimming trajectories under bright illumination. In both deletion transgenic strains, the subunits near the spokehead were restored, but their firm attachment to the spokestalk required the DPY-30 domain. We postulate that the DPY-30-helix dimer is a conserved two-prong linker, required for normal motility, organizing duplicated subunits in the radial spoke stalk and formation of a symmetrical spokehead. Further, the dispensable calmodulin-binding region appears to fine-tune the spokehead for regulation of "steering" motility in the green algae. Thus, in general, D/D domains may function to localize molecular modules for both the assembly and modulation of macromolecular complexes.
Collapse
|
23
|
Gupta A, Diener DR, Sivadas P, Rosenbaum JL, Yang P. The versatile molecular complex component LC8 promotes several distinct steps of flagellar assembly. ACTA ACUST UNITED AC 2012; 198:115-26. [PMID: 22753897 PMCID: PMC3392930 DOI: 10.1083/jcb.201111041] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
LC8 is present in various molecular complexes. However, its role in these complexes remains unclear. We discovered that although LC8 is a subunit of the radial spoke (RS) complex in Chlamydomonas flagella, it was undetectable in the RS precursor that is converted into the mature RS at the tip of elongating axonemes. Interestingly, LC8 dimers bound in tandem to the N-terminal region of a spoke phosphoprotein, RS protein 3 (RSP3), that docks RSs to axonemes. LC8 enhanced the binding of RSP3 N-terminal fragments to purified axonemes. Likewise, the N-terminal fragments extracted from axonemes contained LC8 and putative spoke-docking proteins. Lastly, perturbations of RSP3's LC8-binding sites resulted in asynchronous flagella with hypophosphorylated RSP3 and defective associations between LC8, RSs, and axonemes. We propose that at the tip of flagella, an array of LC8 dimers binds to RSP3 in RS precursors, triggering phosphorylation, stalk base formation, and axoneme targeting. These multiple effects shed new light on fundamental questions about LC8-containing complexes and axoneme assembly.
Collapse
Affiliation(s)
- Anjali Gupta
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53201, USA
| | | | | | | | | |
Collapse
|
24
|
Thakur A, Chitoor B, Goswami AV, Pareek G, Atreya HS, D'Silva P. Structure and mechanistic insights into novel iron-mediated moonlighting functions of human J-protein cochaperone, Dph4. J Biol Chem 2012; 287:13194-205. [PMID: 22367199 PMCID: PMC3339945 DOI: 10.1074/jbc.m112.339655] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
J-proteins are obligate cochaperones of Hsp70s and stimulate their ATPase activity via the J-domain. Although the functions of J-proteins have been well understood in the context of Hsp70s, their additional co-evolved "physiological functions" are still elusive. We report here the solution structure and mechanism of novel iron-mediated functional roles of human Dph4, a type III J-protein playing a vital role in diphthamide biosynthesis and normal development. The NMR structure of Dph4 reveals two domains: a conserved J-domain and a CSL-domain connected via a flexible linker-helix. The linker-helix modulates the conformational flexibility between the two domains, regulating thereby the protein function. Dph4 exhibits a unique ability to bind iron in tetrahedral coordination geometry through cysteines of its CSL-domain. The oxidized Fe-Dph4 shows characteristic UV-visible and electron paramagnetic resonance spectral properties similar to rubredoxins. Iron-bound Dph4 (Fe-Dph4) also undergoes oligomerization, thus potentially functioning as a transient "iron storage protein," thereby regulating the intracellular iron homeostasis. Remarkably, Fe-Dph4 exhibits vital redox and electron carrier activity, which is critical for important metabolic reactions, including diphthamide biosynthesis. Further, we observed that Fe-Dph4 is conformationally better poised to perform Hsp70-dependent functions, thus underlining the significance of iron binding in Dph4. Yeast Jjj3, a functional ortholog of human Dph4 also shows a similar iron-binding property, indicating the conserved nature of iron sequestration across species. Taken together, our findings provide invaluable evidence in favor of additional co-evolved specialized functions of J-proteins, previously not well appreciated.
Collapse
Affiliation(s)
- Anushikha Thakur
- Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | | | | | | | | | | |
Collapse
|
25
|
Pigino G, Bui KH, Maheshwari A, Lupetti P, Diener D, Ishikawa T. Cryoelectron tomography of radial spokes in cilia and flagella. ACTA ACUST UNITED AC 2011; 195:673-87. [PMID: 22065640 PMCID: PMC3257535 DOI: 10.1083/jcb.201106125] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Cryo-EM tomography of wild-type and mutant cilia and flagella from Tetrahymena and Chlamydomonas reveals new information on the substructure of radial spokes. Radial spokes (RSs) are ubiquitous components in the 9 + 2 axoneme thought to be mechanochemical transducers involved in local control of dynein-driven microtubule sliding. They are composed of >23 polypeptides, whose interactions and placement must be deciphered to understand RS function. In this paper, we show the detailed three-dimensional (3D) structure of RS in situ in Chlamydomonas reinhardtii flagella and Tetrahymena thermophila cilia that we obtained using cryoelectron tomography (cryo-ET). We clarify similarities and differences between the three spoke species, RS1, RS2, and RS3, in T. thermophila and in C. reinhardtii and show that part of RS3 is conserved in C. reinhardtii, which only has two species of complete RSs. By analyzing C. reinhardtii mutants, we identified the specific location of subsets of RS proteins (RSPs). Our 3D reconstructions show a twofold symmetry, suggesting that fully assembled RSs are produced by dimerization. Based on our cryo-ET data, we propose models of subdomain organization within the RS as well as interactions between RSPs and with other axonemal components.
Collapse
Affiliation(s)
- Gaia Pigino
- Biomolecular Research Laboratory, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | | | | | | | | | | |
Collapse
|
26
|
Morita M, Nakajima A, Takemura A, Okuno M. Involvement of redox- and phosphorylation-dependent pathways in osmotic adaptation in sperm cells of euryhaline tilapia. ACTA ACUST UNITED AC 2011; 214:2096-104. [PMID: 21613527 DOI: 10.1242/jeb.053405] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Sperm cells involved in fertilisation must tolerate hypo-osmotic and hyper-osmotic environments. Euryhaline tilapia (Oreochromis mossambicus) can acclimatise to and reproduce in freshwater and seawater because its sperm are able to adapt to these differing osmotic environments. In this study, we found that the dephosphorylation of sperm proteins in O. mossambicus correlated with the activation of flagellar motility when sperm were exposed to hypotonic or hypertonic conditions, and that differences in phosphorylation may reflect adaptations to a given osmotic environment. Of the sperm proteins that were dephosphorylated, the phosphorylation pattern of an 18 kDa protein, identified as the superoxide anion scavenger Cu/Zn superoxide dismutase (Cu/Zn SOD), was different in freshwater- and seawater-acclimatised tilapia sperm. Cu/Zn SOD was distributed from the sperm head to the flagellum. Additionally, differences were observed between freshwater and seawater tilapia in the nitration of tyrosine residues (which might be mediated by SOD) in sperm flagellar proteins in response to osmotic shock. These results demonstrate that reactive-oxygen-species-dependent mechanisms contribute to both osmotic tolerance and the activation of flagellar motility.
Collapse
Affiliation(s)
- Masaya Morita
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Sesoko, Motobu, Okinawa 907-0227, Japan.
| | | | | | | |
Collapse
|
27
|
Guan J, Ekwurtzel E, Kvist U, Hultenby K, Yuan L. DNAJB13 is a radial spoke protein of mouse '9+2' axoneme. Reprod Domest Anim 2011; 45:992-6. [PMID: 19919626 DOI: 10.1111/j.1439-0531.2009.01473.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
It has been shown that DNAJB13, a type II heat shock protein 40, is highly expressed in the testis and is an axonemal component of mouse mature spermatozoa. By multi-tissue reverse transcription polymerase chain reaction, we found that Dnajb13 gene was expressed not only in the testis but also in several other ciliated cell-containing tissues like brain, lung and oviduct. Immunohistochemistry on mouse trachea and oviduct sections shown that DNAJB13 was present in the motile cilia of those tissues. To define further its localization in the axoneme, immunoelectron microscopy of mouse sperm flagella was performed and shown that DNAJB13 was localized to radial spokes of the axoneme. Taken together, our data indicate that DNAJB13 is a radial spoke protein of the mouse '9+2' axoneme.
Collapse
Affiliation(s)
- J Guan
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | | | | | | | | |
Collapse
|
28
|
Kohno T, Wakabayashi KI, Diener DR, Rosenbaum JL, Kamiya R. Subunit interactions within the Chlamydomonas flagellar spokehead. Cytoskeleton (Hoboken) 2011; 68:237-46. [PMID: 21391306 DOI: 10.1002/cm.20507] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 02/08/2011] [Indexed: 11/10/2022]
Abstract
The radial spoke (RS)/central pair (CP) system in cilia and flagella plays an essential role in the regulation of force generation by dynein, the motor protein that drives cilia/flagella movements. Mechanical and mechanochemicl interactions between the CP and the distal part of the RS, the spokehead, should be crucial for this control; however, the details of interaction are totally unknown. As an initial step toward an understanding of the RS-CP interaction, we examined the protein-protein interactions between the five spokehead proteins (radial spoke protein (RSP)1, RSP4, RSP6, RSP9, and RSP10) and three spoke stalk proteins (RSP2, RSP5, and RSP23), all expressed as recombinant proteins. Three of them were shown to have physiological activities by electroporation-mediated protein delivery into mutants deficient in the respective proteins. Glutathione S-transferase pulldown assays in vitro detected interactions in 10 out of 64 pairs of recombinants. In addition, chemical crosslinking of axonemes using five reagents detected seven kinds of interactions between the RS subunits in situ. Finally, in the mixture of the recombinant spokehead subunits, RSP1, RSP4, RSP6, and RSP9 formed a 7-10S complex as detected by sucrose density gradient centrifugation. It may represent a partial assembly of the spokehead. From these results, we propose a model of interactions taking place between the spokehead subunits.
Collapse
Affiliation(s)
- Takahiro Kohno
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, Japan
| | | | | | | | | |
Collapse
|
29
|
Kampinga HH, Craig EA. The HSP70 chaperone machinery: J proteins as drivers of functional specificity. Nat Rev Mol Cell Biol 2010; 11:579-92. [PMID: 20651708 PMCID: PMC3003299 DOI: 10.1038/nrm2941] [Citation(s) in RCA: 1191] [Impact Index Per Article: 85.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Heat shock 70 kDa proteins (HSP70s) are ubiquitous molecular chaperones that function in a myriad of biological processes, modulating polypeptide folding, degradation and translocation across membranes, and protein-protein interactions. This multitude of roles is not easily reconciled with the universality of the activity of HSP70s in ATP-dependent client protein-binding and release cycles. Much of the functional diversity of the HSP70s is driven by a diverse class of cofactors: J proteins. Often, multiple J proteins function with a single HSP70. Some target HSP70 activity to clients at precise locations in cells and others bind client proteins directly, thereby delivering specific clients to HSP70 and directly determining their fate.
Collapse
Affiliation(s)
- Harm H Kampinga
- Department of Cell Biology, University of Groningen, University Medical Center, 713 AV Groningen, The Netherlands.
| | | |
Collapse
|
30
|
Seixas C, Cruto T, Tavares A, Gaertig J, Soares H. CCTalpha and CCTdelta chaperonin subunits are essential and required for cilia assembly and maintenance in Tetrahymena. PLoS One 2010; 5:e10704. [PMID: 20502701 PMCID: PMC2872681 DOI: 10.1371/journal.pone.0010704] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Accepted: 04/23/2010] [Indexed: 12/24/2022] Open
Abstract
Background The eukaryotic cytosolic chaperonin CCT is a hetero-oligomeric complex formed by two rings connected back-to-back, each composed of eight distinct subunits (CCTα to CCTζ). CCT complex mediates the folding, of a wide range of newly synthesised proteins including tubulin (α, β and γ) and actin, as quantitatively major substrates. Methodology/Principal Findings We disrupted the genes encoding CCTα and CCTδ subunits in the ciliate Tetrahymena. Cells lacking the zygotic expression of either CCTα or CCTδ showed a loss of cell body microtubules, failed to assemble new cilia and died within 2 cell cycles. We also show that loss of CCT subunit activity leads to axoneme shortening and splaying of tips of axonemal microtubules. An epitope-tagged CCTα rescued the gene knockout phenotype and localized primarily to the tips of cilia. A mutation in CCTα, G346E, at a residue also present in the related protein implicated in the Bardet Biedel Syndrome, BBS6, also caused defects in cilia and impaired CCTα localization in cilia. Conclusions/Significance Our results demonstrate that the CCT subunits are essential and required for ciliary assembly and maintenance of axoneme structure, especially at the tips of cilia.
Collapse
Affiliation(s)
- Cecilia Seixas
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
| | - Teresa Cruto
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | | | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
| | - Helena Soares
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Escola Superior de Tecnologia da Saúde de Lisboa, Lisboa, Portugal
- * E-mail:
| |
Collapse
|
31
|
Lindemann CB, Lesich KA. Flagellar and ciliary beating: the proven and the possible. J Cell Sci 2010; 123:519-28. [PMID: 20145000 DOI: 10.1242/jcs.051326] [Citation(s) in RCA: 156] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The working mechanism of the eukaryotic flagellar axoneme remains one of nature's most enduring puzzles. The basic mechanical operation of the axoneme is now a story that is fairly complete; however, the mechanism for coordinating the action of the dynein motor proteins to produce beating is still controversial. Although a full grasp of the dynein switching mechanism remains elusive, recent experimental reports provide new insights that might finally disclose the secrets of the beating mechanism: the special role of the inner dynein arms, especially dynein I1 and the dynein regulatory complex, the importance of the dynein microtubule-binding affinity at the stalk, and the role of bending in the selection of the active dynein group have all been implicated by major new evidence. This Commentary considers this new evidence in the context of various hypotheses of how axonemal dynein coordination might work.
Collapse
Affiliation(s)
- Charles B Lindemann
- Department of Biological Sciences, Oakland University, Rochester, MI 48309, USA.
| | | |
Collapse
|
32
|
Wei M, Sivadas P, Owen HA, Mitchell DR, Yang P. Chlamydomonas mutants display reversible deficiencies in flagellar beating and axonemal assembly. Cytoskeleton (Hoboken) 2010; 67:71-80. [PMID: 20169531 PMCID: PMC2835312 DOI: 10.1002/cm.20422] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Accepted: 10/14/2009] [Indexed: 11/12/2022]
Abstract
Axonemal complexes in flagella are largely prepackaged in the cell body. As such, one mutation often results in the absence of the co-assembled components and permanent motility deficiencies. For example, a Chlamydomonas mutant defective in RSP4 in the radial spoke (RS), which is critical for bend propagation, has paralyzed flagella that also lack the paralogue RSP6 and three additional RS proteins. Intriguingly, recent studies showed that several mutant strains contain a mixed population of swimmers and paralyzed cells despite their identical genetic background. Here we report a cause underlying these variations. Two new mutants lacking RSP6 swim processively and other components appear normally assembled in early log phase indicating that, unlike RSP4, this paralogue is dispensable. However, swimmers cannot maintain the typical helical trajectory and reactivated cell models tend to spin. Interestingly the motile fraction and the spokehead content dwindle during stationary phase. These results suggest that (1) intact RS is critical for maintaining the rhythm of oscillatory beating and thus the helical trajectory; (2) assembly of the axonemal complex with subtle defects is less efficient and the inefficiency is accentuated in compromised conditions, leading to reversible dyskinesia. Consistently, several organisms only possess one RSP4/6 gene. Gene duplication in Chlamydomonas enhances RS assembly to maintain optimal motility in various environments.
Collapse
Affiliation(s)
- Mei Wei
- Department of Biological Sciences, Marquette University, 530 N. 15 St. Milwaukee, WI 53233
| | - Priyanka Sivadas
- Department of Biological Sciences, Marquette University, 530 N. 15 St. Milwaukee, WI 53233
| | - Heather A. Owen
- Department of Biological Sciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Ave, Milwaukee, WI 53211
| | - David R. Mitchell
- Department of Cell and Developmental Biology, Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210
| | - Pinfen Yang
- Department of Biological Sciences, Marquette University, 530 N. 15 St. Milwaukee, WI 53233
| |
Collapse
|
33
|
Cwc23, an essential J protein critical for pre-mRNA splicing with a dispensable J domain. Mol Cell Biol 2010; 30:33-42. [PMID: 19822657 DOI: 10.1128/mcb.00842-09] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
J proteins are structurally diverse, obligatory cochaperones of Hsp70s, each with a highly conserved J domain that plays a critical role in the stimulation of Hsp70's ATPase activity. The essential protein, Cwc23, is one of 13 J proteins found in the cytosol and/or nucleus of Saccharomyces cerevisiae. We report that a partial loss-of-function CWC23 mutant has severe, global defects in pre-mRNA splicing. This mutation leads to accumulation of the excised, lariat form of the intron, as well as unspliced pre-mRNA, suggesting a role for Cwc23 in spliceosome disassembly. Such a role is further supported by the observation that this mutation results in reduced interaction between Cwc23 and Ntr1 (SPP382), a known component of the disassembly pathway. However, Cwc23 is a very atypical J protein. Its J domain, although functional, is dispensable for both cell viability and pre-mRNA splicing. Nevertheless, strong genetic interactions were uncovered between point mutations encoding alterations in Cwc23's J domain and either Ntr1 or Prp43, a DExD/H-box helicase essential for spliceosome disassembly. These genetic interactions suggest that Hsp70-based chaperone machinery does play a role in the disassembly process. Cwc23 provides a unique example of a J protein; its partnership with Hsp70 plays an auxiliary, rather than a central, role in its essential cellular function.
Collapse
|
34
|
New Insights into the Roles of Molecular Chaperones in Chlamydomonas and Volvox. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 285:75-113. [DOI: 10.1016/b978-0-12-381047-2.00002-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
35
|
Hayashi M, Kamiya R. Protein electroporation into Chlamydomonas for mutant rescue. Methods Cell Biol 2009; 92:107-11. [PMID: 20409801 DOI: 10.1016/s0091-679x(08)92007-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Electroporation can be used to deliver proteins into Chlamydomonas cells. This technique is particularly useful to demonstrate rescue of paralyzed-flagella mutants with recombinant proteins that complement the mutations. The appearance of motile cells immediately provides assurance that the recombinant proteins have their native structures and are functional. It can be also used for the introduction of artificially modified proteins or other substances into live cells.
Collapse
Affiliation(s)
- Masahito Hayashi
- Department of Biological Sciences, University of Tokyo, Bunkyo-ku, Japan
| | | |
Collapse
|
36
|
DiPetrillo C, Smith E. Calcium regulation of ciliary motility analysis of axonemal calcium-binding proteins. Methods Cell Biol 2009; 92:163-80. [PMID: 20409805 DOI: 10.1016/s0091-679x(08)92011-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Substantial data have contributed to a model in which the axonemal microtubules act as a scaffold for the assembly of molecules that form a signal transduction pathway that ultimately regulates dynein. We have also known for some time that for virtually all motile cilia and flagella, the second messenger, calcium, impacts upon these signaling pathways to modulate beating in response to extracellular cues. Yet we are only beginning to identify the axonemal proteins that bind this second messenger and determine their role in regulating dynein-driven microtubule sliding to alter the size and shape of ciliary bends. Here, we review our current understanding of calcium regulation of motility, emphasizing recent advances in the detection and characterization of calcium-binding proteins anchored to the axoneme.
Collapse
Affiliation(s)
- Christen DiPetrillo
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
| | | |
Collapse
|
37
|
Yang P, Yang C, Wirschell M, Davis S. Novel LC8 mutations have disparate effects on the assembly and stability of flagellar complexes. J Biol Chem 2009; 284:31412-21. [PMID: 19696030 DOI: 10.1074/jbc.m109.050666] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
LC8 functions as a dimer crucial for a variety of molecular motors and non-motor complexes. Emerging models, founded on structural studies, suggest that the LC8 dimer promotes the stability and refolding of dimeric target proteins in molecular complexes, and its interactions with selective target proteins, including dynein subunits, is regulated by LC8 phosphorylation, which is proposed to prevent LC8 dimerization. To test these hypotheses in vivo, we determine the impacts of two new LC8 mutations on the assembly and stability of defined LC8-containing complexes in Chlamydomonas flagella. The three types of dyneins and the radial spoke are disparately affected by dimeric LC8 with a C-terminal extension. The defects include the absence of specific subunits, complex instability, and reduced incorporation into the axonemal super complex. Surprisingly, a phosphomimetic LC8 mutation, which is largely monomeric in vitro, is still dimeric in vivo and does not significantly change flagellar generation and motility. The differential defects in these flagellar complexes support the structural model and indicate that modulation of target proteins by LC8 leads to the proper assembly of complexes and ultimately higher level complexes. Furthermore, the ability of flagellar complexes to incorporate the phosphomimetic LC8 protein and the modest defects observed in the phosphomimetic LC8 mutant suggest that LC8 phosphorylation is not an effective mechanism for regulating molecular complexes.
Collapse
Affiliation(s)
- Pinfen Yang
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53233, USA.
| | | | | | | |
Collapse
|
38
|
Elias M, Archibald JM. The RJL family of small GTPases is an ancient eukaryotic invention probably functionally associated with the flagellar apparatus. Gene 2009; 442:63-72. [DOI: 10.1016/j.gene.2009.04.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 04/07/2009] [Accepted: 04/14/2009] [Indexed: 11/29/2022]
|
39
|
D’Souza JS, Gudipati M, Dharmadhikari JA, Dharmadhikari AK, Kashyap A, Aiyer M, Rao U, Mathur D, Rao BJ. Flagella-generated forces reveal gear-type motor in single cells of the green alga, Chlamydomonas reinhardtii. Biochem Biophys Res Commun 2009; 380:266-70. [PMID: 19167361 DOI: 10.1016/j.bbrc.2009.01.049] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 01/13/2009] [Indexed: 10/21/2022]
|
40
|
Abstract
In unicellular and multicellular eukaryotes, fast cell motility and rapid movement of material over cell surfaces are often mediated by ciliary or flagellar beating. The conserved defining structure in most motile cilia and flagella is the '9+2' microtubule axoneme. Our general understanding of flagellum assembly and the regulation of flagellar motility has been led by results from seminal studies of flagellate protozoa and algae. Here we review recent work relating to various aspects of protist physiology and cell biology. In particular, we discuss energy metabolism in eukaryotic flagella, modifications to the canonical assembly pathway and flagellum function in parasite virulence.
Collapse
|
41
|
Seetharam RN, Satir P. Coordination of outer arm dynein activity along axonemal doublet microtubules. ACTA ACUST UNITED AC 2008; 65:572-80. [DOI: 10.1002/cm.20285] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
42
|
LeBrasseur N. Spokes coordinate flagella. J Biophys Biochem Cytol 2008. [PMCID: PMC2213581 DOI: 10.1083/jcb.1802iti3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|