1
|
Godar S, Oristian J, Hinsch V, Wentworth K, Lopez E, Amlashi P, Enverso G, Markley S, Alper JD. Light chain 2 is a Tctex-type related axonemal dynein light chain that regulates directional ciliary motility in Trypanosoma brucei. PLoS Pathog 2022; 18:e1009984. [PMID: 36155669 PMCID: PMC9536576 DOI: 10.1371/journal.ppat.1009984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/06/2022] [Accepted: 08/26/2022] [Indexed: 01/04/2023] Open
Abstract
Flagellar motility is essential for the cell morphology, viability, and virulence of pathogenic kinetoplastids. Trypanosoma brucei flagella beat with a bending wave that propagates from the flagellum's tip to its base, rather than base-to-tip as in other eukaryotes. Thousands of dynein motor proteins coordinate their activity to drive ciliary bending wave propagation. Dynein-associated light and intermediate chains regulate the biophysical mechanisms of axonemal dynein. Tctex-type outer arm dynein light chain 2 (LC2) regulates flagellar bending wave propagation direction, amplitude, and frequency in Chlamydomonas reinhardtii. However, the role of Tctex-type light chains in regulating T. brucei motility is unknown. Here, we used a combination of bioinformatics, in-situ molecular tagging, and immunofluorescence microscopy to identify a Tctex-type light chain in the procyclic form of T. brucei (TbLC2). We knocked down TbLC2 expression using RNAi in both wild-type and FLAM3, a flagellar attachment zone protein, knockdown cells and quantified TbLC2's effects on trypanosome cell biology and biophysics. We found that TbLC2 knockdown reduced the directional persistence of trypanosome cell swimming, induced an asymmetric ciliary bending waveform, modulated the bias between the base-to-tip and tip-to-base beating modes, and increased the beating frequency. Together, our findings are consistent with a model of TbLC2 as a down-regulator of axonemal dynein activity that stabilizes the forward tip-to-base beating ciliary waveform characteristic of trypanosome cells. Our work sheds light on axonemal dynein regulation mechanisms that contribute to pathogenic kinetoplastids' unique tip-to-base ciliary beating nature and how those mechanisms underlie dynein-driven ciliary motility more generally.
Collapse
Affiliation(s)
- Subash Godar
- Department of Physics and Astronomy, College of Science, Clemson University, Clemson, South Carolina, United States of America
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
| | - James Oristian
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Genetics and Biochemistry, College of Science, Clemson University, Clemson, South Carolina, United States of America
| | - Valerie Hinsch
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Genetics and Biochemistry, College of Science, Clemson University, Clemson, South Carolina, United States of America
| | - Katherine Wentworth
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Biological Sciences, College of Science, Clemson University, Clemson, South Carolina, United States of America
| | - Ethan Lopez
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Genetics and Biochemistry, College of Science, Clemson University, Clemson, South Carolina, United States of America
| | - Parastoo Amlashi
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Biological Sciences, College of Science, Clemson University, Clemson, South Carolina, United States of America
| | - Gerald Enverso
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Biological Sciences, College of Science, Clemson University, Clemson, South Carolina, United States of America
| | - Samantha Markley
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Biological Sciences, College of Science, Clemson University, Clemson, South Carolina, United States of America
| | - Joshua Daniel Alper
- Department of Physics and Astronomy, College of Science, Clemson University, Clemson, South Carolina, United States of America
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Biological Sciences, College of Science, Clemson University, Clemson, South Carolina, United States of America
| |
Collapse
|
2
|
Braschi B, Omran H, Witman GB, Pazour GJ, Pfister KK, Bruford EA, King SM. Consensus nomenclature for dyneins and associated assembly factors. J Cell Biol 2022; 221:e202109014. [PMID: 35006274 PMCID: PMC8754002 DOI: 10.1083/jcb.202109014] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 09/10/2021] [Accepted: 12/13/2021] [Indexed: 12/12/2022] Open
Abstract
Dyneins are highly complex, multicomponent, microtubule-based molecular motors. These enzymes are responsible for numerous motile behaviors in cytoplasm, mediate retrograde intraflagellar transport (IFT), and power ciliary and flagellar motility. Variants in multiple genes encoding dyneins, outer dynein arm (ODA) docking complex subunits, and cytoplasmic factors involved in axonemal dynein preassembly (DNAAFs) are associated with human ciliopathies and are of clinical interest. Therefore, clear communication within this field is particularly important. Standardizing gene nomenclature, and basing it on orthology where possible, facilitates discussion and genetic comparison across species. Here, we discuss how the human gene nomenclature for dyneins, ODA docking complex subunits, and DNAAFs has been updated to be more functionally informative and consistent with that of the unicellular green alga Chlamydomonas reinhardtii, a key model organism for studying dyneins and ciliary function. We also detail additional nomenclature updates for vertebrate-specific genes that encode dynein chains and other proteins involved in dynein complex assembly.
Collapse
Affiliation(s)
- Bryony Braschi
- HUGO Gene Nomenclature Committee, European Molecular Biology Laboratory, European Bioinformatics Institute, Hinxton, Cambridgeshire, UK
| | - Heymut Omran
- Department of General Pediatrics, University Hospital Muenster, Muenster, Germany
| | - George B. Witman
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
| | - Gregory J. Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech II, Worcester, MA
| | - K. Kevin Pfister
- Cell Biology Department, School of Medicine University of Virginia, Charlottesville, VA
| | - Elspeth A. Bruford
- HUGO Gene Nomenclature Committee, European Molecular Biology Laboratory, European Bioinformatics Institute, Hinxton, Cambridgeshire, UK
- Department of Haematology, University of Cambridge School of Clinical Medicine, Cambridge, Cambridgeshire, UK
| | - Stephen M. King
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT
| |
Collapse
|
3
|
Tourmente M, Varea-Sánchez M, Roldan ERS. Faster and more efficient swimming: energy consumption of murine spermatozoa under sperm competition†. Biol Reprod 2020; 100:420-428. [PMID: 30203065 DOI: 10.1093/biolre/ioy197] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 06/22/2018] [Accepted: 09/08/2018] [Indexed: 11/14/2022] Open
Abstract
ATP supply is essential for sperm performance and increases in ATP content coevolve with enhanced sperm swimming velocity as a response to sperm competition in rodents. ATP content is the balance between production and consumption but, although ATP production has received much attention, little is known about ATP consumption. The rate of ATP consumption is crucial for the propagation of the flagellar wave, becoming a main determinant of the time and distance sperm could move before exhausting their reserves. A high yield in distance per unit of ATP consumed (efficiency) could provide advantages in sperm competition. We characterized sperm ATP consumption rate in a group of mouse species with different sperm competition levels to understand its impact on swimming velocity, duration, and yield of sperm ATP reserves. Interspecific comparisons revealed that sperm of species with higher sperm competition levels had high ATP consumption rates and faster swimming velocity. Moreover, sperm that consumed ATP at a faster rate swam more efficiently, since they were able to cover more distance per unit of ATP consumed. Our results suggest that by coupling the advantages of higher ATP turnover rates to increased efficiency of ATP expenditure, sperm would respond to increasingly competitive environments while maintaining a positive ATP balance.
Collapse
Affiliation(s)
- Maximiliano Tourmente
- Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales, Madrid, Spain
- College of Life and Environmental Sciences, University of Exeter, Penryn, UK
| | - María Varea-Sánchez
- Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales, Madrid, Spain
| | - Eduardo R S Roldan
- Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales, Madrid, Spain
| |
Collapse
|
4
|
Liu Y, Zhang L, Li W, Li Y, Liu J, Zhang S, Pin G, Song S, Ray PF, Arnoult C, Cho C, Garcia-Reyes B, Knippschild U, Strauss JF, Zhang Z. The sperm-associated antigen 6 interactome and its role in spermatogenesis. Reproduction 2019; 158:181-197. [PMID: 31146259 PMCID: PMC7368494 DOI: 10.1530/rep-18-0522] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 05/30/2019] [Indexed: 12/18/2022]
Abstract
Mammalian SPAG6, the orthologue of Chlamydomonas reinhardtii PF16, is a component of the central apparatus of the '9 + 2' axoneme that controls ciliary/flagellar motility, including sperm motility. Recent studies revealed that SPAG6 has functions beyond its role in the central apparatus. Hence, we reexamined the role of SPAG6 in male fertility. In wild-type mice, SPAG6 was present in cytoplasmic vesicles in spermatocytes, the acrosome of round and elongating spermatids and the manchette of elongating spermatids. Spag6-deficient testes showed abnormal spermatogenesis, with abnormalities in male germ cell morphology consistent with the multi-compartment pattern of SPAG6 localization. The armadillo repeat domain of mouse SPAG6 was used as a bait in a yeast two-hybrid screen, and several proteins with diverse functions appeared multiple times, including Snapin, SPINK2 and COPS5. Snapin has a similar localization to SPAG6 in male germ cells, and SPINK2, a key protein in acrosome biogenesis, was dramatically reduced in Spag6-deficient mice which have defective acrosomes. SPAG16L, another SPAG6-binding partner, lost its localization to the manchette in Spag6-deficient mice. Our findings demonstrate that SPAG6 is a multi-functional protein that not only regulates sperm motility, but also plays roles in spermatogenesis in multiple cellular compartments involving multiple protein partners.
Collapse
Affiliation(s)
- Yunhao Liu
- School of Public Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, Hubei, 430065
| | - Ling Zhang
- School of Public Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, Hubei, 430065
| | - Wei Li
- Department of Physiology, Wayne State University, Detroit, MI, 48201
| | - Yuhong Li
- School of Public Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, Hubei, 430065
| | - Junpin Liu
- School of Public Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, Hubei, 430065
| | - Shiyang Zhang
- School of Public Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, Hubei, 430065
| | - Guanglun Pin
- School of Public Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, Hubei, 430065
| | - Shizhen Song
- School of Public Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, Hubei, 430065
| | - Pierre F Ray
- Genetic Epigenetic and Therapies of Infertility, Institute for Advanced Biosciences, Inserm U1209, CNRS UMR 5309, Université Grenoble Alpes, Grenoble, France
| | - Christophe Arnoult
- Genetic Epigenetic and Therapies of Infertility, Institute for Advanced Biosciences, Inserm U1209, CNRS UMR 5309, Université Grenoble Alpes, Grenoble, France
| | - Chunghee Cho
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Balbina Garcia-Reyes
- Department of General and Visceral Surgery, Ulm University, Albert-Einstein-Allee 23, D-89081, Ulm, Germany
| | - Uwe Knippschild
- Department of General and Visceral Surgery, Ulm University, Albert-Einstein-Allee 23, D-89081, Ulm, Germany
| | - Jerome F. Strauss
- Department of Obstetrics/Gynecology, Virginia Commonwealth University, Richmond, VA, 23298
| | - Zhibing Zhang
- Department of Physiology, Wayne State University, Detroit, MI, 48201
- Department of Obstetrics/Gynecology, Wayne State University, Detroit, MI, 48201
| |
Collapse
|
5
|
Viswanadha R, Sale WS, Porter ME. Ciliary Motility: Regulation of Axonemal Dynein Motors. Cold Spring Harb Perspect Biol 2017; 9:9/8/a018325. [PMID: 28765157 DOI: 10.1101/cshperspect.a018325] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Ciliary motility is crucial for the development and health of many organisms. Motility depends on the coordinated activity of multiple dynein motors arranged in a precise pattern on the outer doublet microtubules. Although significant progress has been made in elucidating the composition and organization of the dyneins, a comprehensive understanding of dynein regulation is lacking. Here, we focus on two conserved signaling complexes located at the base of the radial spokes. These include the I1/f inner dynein arm associated with radial spoke 1 and the calmodulin- and spoke-associated complex and the nexin-dynein regulatory complex associated with radial spoke 2. Current research is focused on understanding how these two axonemal hubs coordinate and regulate the dynein motors and ciliary motility.
Collapse
Affiliation(s)
- Rasagnya Viswanadha
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Winfield S Sale
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Mary E Porter
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455
| |
Collapse
|
6
|
Parveen Z, Bibi Z, Bibi N, Neesen J, Rashid S. Disruption of murine Tcte3-3 induces tissue specific apoptosis via co-expression of Anxa5 and Pebp1. Comput Biol Chem 2014; 53PB:214-225. [PMID: 25462330 DOI: 10.1016/j.compbiolchem.2014.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 10/12/2014] [Accepted: 10/21/2014] [Indexed: 01/07/2023]
Abstract
Programmed cell death or apoptosis plays a vital physiological role in the development and homeostasis. Any discrepancy in apoptosis may trigger testicular and neurodegenerative diseases, ischemic damage, autoimmune disorders and many types of cancer. Tcte3 (T-complex testis expressed 3) is an accessory component of axonemal and cytoplasmic dynein which expresses predominantly in meiotic and postmeiotic germ cells. It plays an essential role during spermatogenesis; however, to explore its diverse and complex functioning in male germ cell apoptosis, requires further prosecution. Here, 2D-gel electrophoresis, mass spectrometry and qRT-PCR analyses were performed to elucidate the differential expression of genes, in both wild-type and homozygous Tcte3-3 mice. We observed an increased expression of Tcte3 in homozygotes as compared to wild-type testes. Perpetually, an increased expression of Anxa5 and Pebp1, while a lower expression of Rsph1 was detected in Tcte3-3-/- mice. We propose that over-expression of Pebp1 and Anxa5 in Tcte3-3-/- testes might be due to increased apoptosis. To evaluate this possibility, testes specific microarray data set extracted from NCBI gene ontology omnibus (GEO) was used to cluster the possible co-expression partners of Tcte3. Further functional coherence of compiled candidate genes was monitored computationally by studying the common TFBS overlapped at the regulatory regions. Differential expression of Tcte3-3 and its involvement in apoptosis may provide a basis for the investigation of transcriptional specificities of other Tcte3 paralogs (Tcte3-1 and Tcte3-2). A complete understanding of controlling factors which have implications in regulating tissue-specific Tcte3 expression would provide additional insights into the gene control events. The collective knowledge may prove useful for the development of novel therapeutic regimen and would open new avenues in defining selective roles of Tcte3 in germ cell development.
Collapse
Affiliation(s)
- Zahida Parveen
- National Center for Bioinformatics, Quaid-i-Azam University, Islamabad, Pakistan
| | - Zohra Bibi
- National Center for Bioinformatics, Quaid-i-Azam University, Islamabad, Pakistan
| | - Nousheen Bibi
- National Center for Bioinformatics, Quaid-i-Azam University, Islamabad, Pakistan
| | - Juergen Neesen
- Institute of Medical Genetics, Medical University of Vienna, Austria
| | - Sajid Rashid
- National Center for Bioinformatics, Quaid-i-Azam University, Islamabad, Pakistan.
| |
Collapse
|
7
|
Asante D, Stevenson NL, Stephens DJ. Subunit composition of the human cytoplasmic dynein-2 complex. J Cell Sci 2014; 127:4774-87. [PMID: 25205765 PMCID: PMC4215718 DOI: 10.1242/jcs.159038] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cytoplasmic dynein-2 is the motor for retrograde intraflagellar transport (IFT), and mutations in dynein-2 are known to cause skeletal ciliopathies. Here, we define for the first time the composition of the human cytoplasmic dynein-2 complex. We show that the proteins encoded by the ciliopathy genes WDR34 and WDR60 are bona fide dynein-2 intermediate chains and are both required for dynein-2 function. In addition, we identify TCTEX1D2 as a unique dynein-2 light chain that is itself required for cilia function. We define several subunits common to both dynein-1 and dynein-2, including TCTEX-1 (also known as DYNLT1) and TCTEX-3 (also known as DYNLT3), roadblock-1 (also known as DYNLRB1) and roadblock-2 (also known as DYNLRB2), and LC8-1 and LC8-2 light chains (DYNLL1 and DYNLL2, respectively). We also find that NudCD3 associates with dynein-2 as it does with dynein-1. By contrast, the common dynein-1 regulators dynactin, LIS1 (also known as PAFAH1B1) and BICD2 are not found in association with dynein-2. These data explain why mutations in either WDR34 or WDR60 cause disease, as well as identifying TCTEX1D2 as a candidate ciliopathy gene.
Collapse
Affiliation(s)
- David Asante
- Cell Biology Laboratories, School of Biochemistry, Medical Sciences Building, University of Bristol, Bristol BS8 1TD, UK
| | - Nicola L Stevenson
- Cell Biology Laboratories, School of Biochemistry, Medical Sciences Building, University of Bristol, Bristol BS8 1TD, UK
| | - David J Stephens
- Cell Biology Laboratories, School of Biochemistry, Medical Sciences Building, University of Bristol, Bristol BS8 1TD, UK
| |
Collapse
|
8
|
Korrodi-Gregório L, Vieira SI, Esteves SLC, Silva JV, Freitas MJ, Brauns AK, Luers G, Abrantes J, Esteves PJ, da Cruz E Silva OAB, Fardilha M, da Cruz E Silva EF. TCTEX1D4, a novel protein phosphatase 1 interactor: connecting the phosphatase to the microtubule network. Biol Open 2013; 2:453-65. [PMID: 23789093 PMCID: PMC3654263 DOI: 10.1242/bio.20131065] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 01/16/2013] [Indexed: 12/11/2022] Open
Abstract
Reversible phosphorylation plays an important role as a mechanism of intracellular control in eukaryotes. PPP1, a major eukaryotic Ser/Thr-protein phosphatase, acquires its specificity by interacting with different protein regulators, also known as PPP1 interacting proteins (PIPs). In the present work we characterized a physiologically relevant PIP in testis. Using a yeast two-hybrid screen with a human testis cDNA library, we identified a novel PIP of PPP1CC2 isoform, the T-complex testis expressed protein 1 domain containing 4 (TCTEX1D4) that has recently been described as a Tctex1 dynein light chain family member. The overlay assays confirm that TCTEX1D4 interacts with the different spliced isoforms of PPP1CC. Also, the binding domain occurs in the N-terminus, where a consensus PPP1 binding motif (PPP1BM) RVSF is present. The distribution of TCTEX1D4 in testis suggests its involvement in distinct functions, such as TGFβ signaling at the blood–testis barrier and acrosome cap formation. Immunofluorescence in human ejaculated sperm shows that TCTEX1D4 is present in the flagellum and in the acrosome region of the head. Moreover, TCTEX1D4 and PPP1 co-localize in the microtubule organizing center (MTOC) and microtubules in cell cultures. Importantly, the TCTEX1D4 PPP1BM seems to be relevant for complex formation, for PPP1 retention in the MTOC and movement along microtubules. These novel results open new avenues to possible roles of this dynein, together with PPP1. In essence TCTEX1D4/PPP1C complex appears to be involved in microtubule dynamics, sperm motility, acrosome reaction and in the regulation of the blood–testis barrier.
Collapse
Affiliation(s)
- Luís Korrodi-Gregório
- Laboratory of Signal Transduction, Centre for Cell Biology, Biology Department, University of Aveiro , 3810-193 Aveiro , Portugal
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Rompolas P, Patel-King RS, King SM. Association of Lis1 with outer arm dynein is modulated in response to alterations in flagellar motility. Mol Biol Cell 2012; 23:3554-65. [PMID: 22855525 PMCID: PMC3442404 DOI: 10.1091/mbc.e12-04-0287] [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: 11/30/2022] Open
Abstract
The cytoplasmic dynein regulatory factor Lis1, which induces a persistent tight binding to microtubules and allows for transport of cargoes under high-load conditions, is also present in motile cilia/flagella. Lis1 levels in cilia/flagella are dynamically modulated in response to imposed alterations in beat parameters. The cytoplasmic dynein regulatory factor Lis1, which induces a persistent tight binding to microtubules and allows for transport of cargoes under high-load conditions, is also present in motile cilia/flagella. We observed that Lis1 levels in flagella of Chlamydomonas strains that exhibit defective motility due to mutation of various axonemal substructures were greatly enhanced compared with wild type; this increase was absolutely dependent on the presence within the flagellum of the outer arm dynein α heavy chain/light chain 5 thioredoxin unit. To assess whether cells might interpret defective motility as a “high-load environment,” we reduced the flagellar beat frequency of wild-type cells through enhanced viscous load and by reductive stress; both treatments resulted in increased levels of flagellar Lis1, which altered the intrinsic beat frequency of the trans flagellum. Differential extraction of Lis1 from wild-type and mutant axonemes suggests that the affinity of outer arm dynein for Lis1 is directly modulated. In cytoplasm, Lis1 localized to two punctate structures, one of which was located near the base of the flagella. These data reveal that the cell actively monitors motility and dynamically modulates flagellar levels of the dynein regulatory factor Lis1 in response to imposed alterations in beat parameters.
Collapse
Affiliation(s)
- Panteleimon Rompolas
- Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, Farmington, CT 06030-3305, USA
| | | | | |
Collapse
|
10
|
Rashid S, Grzmil P, Drenckhahn JD, Meinhardt A, Adham I, Engel W, Neesen J. Disruption of the murine dynein light chain gene Tcte3-3 results in asthenozoospermia. Reproduction 2010; 139:99-111. [PMID: 19778998 DOI: 10.1530/rep-09-0243] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To elucidate the role of the mouse gene Tcte3 (Tctex2), which encodes a putative light chain of the outer dynein arm of cilia and sperm flagella, we have inactivated this gene in mice using targeted disruption. Breeding of heterozygous males and females resulted in normal litter size; however, we were not able to detect homozygous Tcte3-deficent mice using standard genotype techniques. In fact, our results indicate the presence of at least three highly similar copies of the Tcte3 gene (Tcte3-1, Tcte3-2, and Tcte3-3) in the murine genome. Therefore, quantitative real-time PCR was established to differentiate between mice having one or two targeted Tcte3-3 alleles. By this approach, Tcte3-3(-/-) animals were identified, which were viable and revealed no obvious malformation. Interestingly, some homozygous Tcte3-3-deficient male mice bred with wild-type female produced no offspring while other Tcte3-3-deficient males revealed decreased sperm motility but were fertile. In infertile Tcte3-3(-/-) males, spermatogenesis was affected and sperm motility was reduced, too, resulting in decreased ability of Tcte3-3-deficient spermatozoa to move from the uterus into the oviduct. Impaired flagellar motility is not correlated with any gross defects in the axonemal structure, since outer dynein arms are detectable in sperm of Tcte3-3(-/-) males. However, in infertile males, deficient Tcte3-3 function is correlated with increased apoptosis during male germ cell development, resulting in a reduction of sperm number. Moreover, multiple malformations in developing haploid germ cells are present. Our results support a role of Tcte3-3 in generation of sperm motility as well as in male germ cell differentiation.
Collapse
Affiliation(s)
- Sajid Rashid
- Institute of Human Genetics, University of Goettingen, 37073 Goettingen, Germany
| | | | | | | | | | | | | |
Collapse
|
11
|
Furuta A, Yagi T, Yanagisawa HA, Higuchi H, Kamiya R. Systematic Comparison of in Vitro Motile Properties between Chlamydomonas Wild-type and Mutant Outer Arm Dyneins Each Lacking One of the Three Heavy Chains. J Biol Chem 2009; 284:5927-35. [DOI: 10.1074/jbc.m807830200] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
12
|
Partially functional outer-arm dynein in a novel Chlamydomonas mutant expressing a truncated gamma heavy chain. EUKARYOTIC CELL 2008; 7:1136-45. [PMID: 18487347 DOI: 10.1128/ec.00102-08] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The outer dynein arm of Chlamydomonas flagella contains three heavy chains (alpha, beta, and gamma), each of which exhibits motor activity. How they assemble and cooperate is of considerable interest. Here we report the isolation of a novel mutant, oda2-t, whose gamma heavy chain is truncated at about 30% of the sequence. While the previously isolated gamma chain mutant oda2 lacks the entire outer arm, oda2-t retains outer arms that contain alpha and beta heavy chains, suggesting that the N-terminal sequence (corresponding to the tail region) is necessary and sufficient for stable outer-arm assembly. Thin-section electron microscopy and image analysis localize the gamma heavy chain to a basal region of the outer-arm image in the axonemal cross section. The motility of oda2-t is lower than that of the wild type and oda11 (lacking the alpha heavy chain) but higher than that of oda2 and oda4-s7 (lacking the motor domain of the beta heavy chain). Thus, the outer-arm dynein lacking the gamma heavy-chain motor domain is partially functional. The availability of mutants lacking individual heavy chains should greatly facilitate studies on the structure and function of the outer-arm dynein.
Collapse
|
13
|
Abstract
Dyneins are large minus-end-directed microtubule motors. Each dynein contains at least one dynein heavy chain (DHC) and a variable number of intermediate chains (IC), light intermediate chains (LIC) and light chains (LC). Here, we used genome sequence data from 24 diverse eukaryotes to assess the distribution of DHCs, ICs, LICs and LCs across Eukaryota. Phylogenetic inference identified nine DHC families (two cytoplasmic and seven axonemal) and six IC families (one cytoplasmic). We confirm that dyneins have been lost from higher plants and show that this is most likely because of a single loss of cytoplasmic dynein 1 from the ancestor of Rhodophyta and Viridiplantae, followed by lineage-specific losses of other families. Independent losses in Entamoeba mean that at least three extant eukaryotic lineages are entirely devoid of dyneins. Cytoplasmic dynein 2 is associated with intraflagellar transport (IFT), but in two chromalveolate organisms, we find an IFT footprint without the retrograde motor. The distribution of one family of outer-arm dyneins accounts for 2-headed or 3-headed outer-arm ultrastructures observed in different organisms. One diatom species builds motile axonemes without any inner-arm dyneins (IAD), and the unexpected conservation of IAD I1 in non-flagellate algae and LC8 (DYNLL1/2) in all lineages reveals a surprising fluidity to dynein function.
Collapse
|
14
|
Rompolas P, Pedersen LB, Patel-King RS, King SM. Chlamydomonas FAP133 is a dynein intermediate chain associated with the retrograde intraflagellar transport motor. J Cell Sci 2007; 120:3653-65. [PMID: 17895364 DOI: 10.1242/jcs.012773] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Intraflagellar transport (IFT) is the bi-directional movement of particles along the length of axonemal outer doublet microtubules and is needed for the assembly and maintenance of eukaryotic cilia and flagella. Retrograde IFT requires cytoplasmic dynein 1b, a motor complex whose organization, structural composition and regulation is poorly understood. We have characterized the product of the Chlamydomonas FAP133 gene that encodes a new WD-repeat protein similar to dynein intermediate chains and homologous to the uncharacterized vertebrate protein WD34. FAP133 is located at the peri-basal body region as well as in punctate structures along the flagella. This protein is associated with the IFT machinery because it is specifically depleted from the flagella of cells with defects in anterograde IFT. Fractionation of flagellar matrix proteins indicates that FAP133 associates with both the LC8 dynein light chain and the IFT dynein heavy chain and light intermediate chain (DHC1b-D1bLIC) motor complex. In the absence of DHC1b or D1bLIC, FAP133 fails to localize at the peri-basal body region but, rather, is concentrated in a region of the cytoplasm near the cell center. Furthermore, we found that FAP133, LC8, DHC1b, D1bLIC, the FLA10 kinesin-2 necessary for anterograde IFT and other IFT scaffold components associate to form a large macromolecular assembly.
Collapse
Affiliation(s)
- Panteleimon Rompolas
- Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | | | | | | |
Collapse
|
15
|
Pedersen LB, Rompolas P, Christensen ST, Rosenbaum JL, King SM. The lissencephaly protein Lis1 is present in motile mammalian cilia and requires outer arm dynein for targeting to Chlamydomonas flagella. J Cell Sci 2007; 120:858-67. [PMID: 17314247 DOI: 10.1242/jcs.03374] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lissencephaly is a developmental brain disorder characterized by a smooth cerebral surface, thickened cortex and misplaced neurons. Classical lissencephaly is caused by mutations in LIS1, which encodes a WD-repeat protein involved in cytoplasmic dynein regulation, mitosis and nuclear migration. Several proteins required for nuclear migration in Aspergillus bind directly to Lis1, including NudC. Mammalian NudC is highly expressed in ciliated epithelia, and localizes to motile cilia in various tissues. Moreover, a NudC ortholog is upregulated upon deflagellation in Chlamydomonas. We found that mammalian Lis1 localizes to motile cilia in trachea and oviduct, but is absent from non-motile primary cilia. Furthermore, we cloned a gene encoding a Lis1-like protein (CrLis1) from Chlamydomonas. CrLis1 is a approximately 37 kDa protein that contains seven WD-repeat domains, similar to Lis1 proteins from other organisms. Immunoblotting using an anti-CrLis1 antibody revealed that this protein is present in the flagellum and is depleted from flagella of mutants with defective outer dynein arm assembly, including one strain that lacks only the alpha heavy chain/light chain 5 thioredoxin complex. Biochemical experiments confirmed that CrLis1 associates with outer dynein arm components and revealed that CrLis1 binds directly to rat NudC. Our results suggest that Lis1 and NudC are present in cilia and flagella and may regulate outer dynein arm activity.
Collapse
Affiliation(s)
- Lotte B Pedersen
- Department of Molecular Biology, University of Copenhagen, Universitetsparken 13, DK-2100 Copenhagen OE, Denmark.
| | | | | | | | | |
Collapse
|
16
|
Wilkes DE, Rajagopalan V, Chan CWC, Kniazeva E, Wiedeman AE, Asai DJ. Dynein light chain family in Tetrahymena thermophila. ACTA ACUST UNITED AC 2007; 64:82-96. [PMID: 17009324 DOI: 10.1002/cm.20165] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Dyneins are large protein complexes that produce directed movement on microtubules. In situ, dyneins comprise combinations of heavy, intermediate, light-intermediate, and light chains. The light chains regulate the locations and activities of dyneins but their functions are not completely understood. We have searched the recently sequenced Tetrahymena thermophila macronuclear genome to describe the entire family of dynein light chains expressed in this organism. We identified fourteen genes encoding putative dynein light chains and seven genes encoding light chain-like proteins. RNA-directed PCR revealed that all 21 genes were expressed. Quantitative real time reverse transcription PCR showed that many of these genes were upregulated after deciliation, indicating that these proteins are present in cilia. Using the nomenclature developed in Chlamydomonas, Tetrahymena expresses two isoforms each of LC2, LC4, LC7, and Tctex1, three isoforms of p28, and six LC8/LC8-like isoforms. Tetrahymena also expresses two LC3-like genes. No Tetrahymena orthologue was found for Chlamydomonas LC5 or LC6. This study provides a complete description of the different genes and isoforms of the dynein light chains that are expressed in Tetrahymena, a model organism in which the targeted manipulation of genes is straightforward.
Collapse
Affiliation(s)
- David E Wilkes
- Department of Biology, Harvey Mudd College, Claremont, California 91711-5990, USA
| | | | | | | | | | | |
Collapse
|
17
|
Pfister KK, Shah PR, Hummerich H, Russ A, Cotton J, Annuar AA, King SM, Fisher EMC. Genetic analysis of the cytoplasmic dynein subunit families. PLoS Genet 2006; 2:e1. [PMID: 16440056 PMCID: PMC1331979 DOI: 10.1371/journal.pgen.0020001] [Citation(s) in RCA: 206] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cytoplasmic dyneins, the principal microtubule minus-end-directed motor proteins of the cell, are involved in many essential cellular processes. The major form of this enzyme is a complex of at least six protein subunits, and in mammals all but one of the subunits are encoded by at least two genes. Here we review current knowledge concerning the subunits, their interactions, and their functional roles as derived from biochemical and genetic analyses. We also carried out extensive database searches to look for new genes and to clarify anomalies in the databases. Our analysis documents evolutionary relationships among the dynein subunits of mammals and other model organisms, and sheds new light on the role of this diverse group of proteins, highlighting the existence of two cytoplasmic dynein complexes with distinct cellular roles.
Collapse
Affiliation(s)
- K Kevin Pfister
- Department of Cell Biology, School of Medicine, University of Virginia, Charlottesville, Virginia, USA.
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Pazour GJ, Agrin N, Walker BL, Witman GB. Identification of predicted human outer dynein arm genes: candidates for primary ciliary dyskinesia genes. J Med Genet 2006; 43:62-73. [PMID: 15937072 PMCID: PMC2593024 DOI: 10.1136/jmg.2005.033001] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 05/10/2005] [Accepted: 05/18/2005] [Indexed: 11/03/2022]
Abstract
BACKGROUND Primary ciliary dyskinesia (PCD) is a severe inherited disorder characterised by chronic respiratory disease, male infertility, and, in approximately 50% of affected individuals, a left-right asymmetry defect called situs inversus. PCD is caused by defects in substructures of the ciliary and flagellar axoneme, most commonly loss of the outer dynein arms. Although PCD is believed to involve mutations in many genes, only three have been identified. METHODS To facilitate discovery of new PCD genes, we have used database searching and analysis to systematically identify the human homologues of proteins associated with the Chlamydomonas reinhardtii outer dynein arm, the best characterised outer arm of any species. RESULTS We find that 12 out of 14 known Chlamydomonas outer arm subunits have one or more likely orthologues in humans. The results predict a total of 24 human genes likely to encode outer dynein arm subunits and associated proteins possibly necessary for outer arm assembly, plus 12 additional closely related human genes likely to encode inner dynein arm subunits. CONCLUSION These genes, which have been located on the human chromosomes for easy comparison with known or suspected PCD loci, are excellent candidates for screening for disease-causing mutations in PCD patients with outer and/or inner dynein arm defects.
Collapse
|
19
|
Song J, Tyler RC, Lee MS, Tyler EM, Markley JL. Solution structure of isoform 1 of Roadblock/LC7, a light chain in the dynein complex. J Mol Biol 2005; 354:1043-51. [PMID: 16289575 DOI: 10.1016/j.jmb.2005.10.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2005] [Accepted: 10/05/2005] [Indexed: 10/25/2022]
Abstract
Roadblock/LC7 is a member of a class of dynein light chains involved in regulating the function of the dynein complex. We have determined the three-dimensional structure of isoform 1 of the mouse Roadblock/LC7 cytoplasmic dynein light chain (robl1_mouse) by NMR spectroscopy. In contrast to a previously reported NMR structure of the human homolog with 96% sequence identity (PDB 1TGQ), which showed the protein as a monomer, our results indicate clearly that robl1 exists as a symmetric homodimer. The two beta3-strands pair with each other and form a continuous ten-stranded beta-sheet. The 25-residue alpha2-helix from one subunit packs antiparallel to that of the other subunit on the face of the beta-sheet. Zipper-like hydrophobic contacts between the two helices serve to stabilize the dimer. Through an NMR titration experiment, we localized the site on robl1_mouse that interacts with the 40 residue peptide spanning residues 243 through 282 of IC74-1_rat. These results provide physical evidence for a symmetrical interaction between dimeric robl1 and the two molecules of IC74-1 in the dynein complex.
Collapse
Affiliation(s)
- Jikui Song
- Center for Eukaryotic Structural Genomics, Department of Biochemistry, University of Wisconsin-Madison, WI 53706-1544, USA
| | | | | | | | | |
Collapse
|
20
|
DiBella LM, Gorbatyuk O, Sakato M, Wakabayashi KI, Patel-King RS, Pazour GJ, Witman GB, King SM. Differential light chain assembly influences outer arm dynein motor function. Mol Biol Cell 2005; 16:5661-74. [PMID: 16195342 PMCID: PMC1289411 DOI: 10.1091/mbc.e05-08-0732] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Tctex1 and Tctex2 were originally described as potential distorters/sterility factors in the non-Mendelian transmission of t-haplotypes in mice. These proteins have since been identified as subunits of cytoplasmic and/or axonemal dyneins. Within the Chlamydomonas flagellum, Tctex1 is a subunit of inner arm I1. We have now identified a second Tctex1-related protein (here termed LC9) in Chlamydomonas. LC9 copurifies with outer arm dynein in sucrose density gradients and is missing only in those strains completely lacking this motor. Zero-length cross-linking of purified outer arm dynein indicates that LC9 interacts directly with both the IC1 and IC2 intermediate chains. Immunoblot analysis revealed that LC2, LC6, and LC9 are missing in an IC2 mutant strain (oda6-r88) that can assemble outer arms but exhibits significantly reduced flagellar beat frequency. This defect is unlikely to be due to lack of LC6, because an LC6 null mutant (oda13) exhibits only a minor swimming abnormality. Using an LC2 null mutant (oda12-1), we find that although some outer arm dynein components assemble in the absence of LC2, they are nonfunctional. In contrast, dyneins from oda6-r88, which also lack LC2, retain some activity. Furthermore, we observed a synthetic assembly defect in an oda6-r88 oda12-1 double mutant. These data suggest that LC2, LC6, and LC9 have different roles in outer arm assembly and are required for wild-type motor function in the Chlamydomonas flagellum.
Collapse
Affiliation(s)
- Linda M DiBella
- Department of Molecular, Microbial, and Structural Biology, University of Connecticut Health Center, Farmington, CT 06030-3305, USA
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Wu H, Maciejewski MW, Takebe S, King SM. Solution structure of the Tctex1 dimer reveals a mechanism for dynein-cargo interactions. Structure 2005; 13:213-23. [PMID: 15698565 DOI: 10.1016/j.str.2004.11.013] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2004] [Revised: 11/10/2004] [Accepted: 11/15/2004] [Indexed: 11/19/2022]
Abstract
Tctex1 is a light chain found in both cytoplasmic and flagellar dyneins and is involved in many fundamental cellular activities, including rhodopsin transport within photoreceptors, and may function in the non-Mendelian transmission of t haplotypes in mice. Here, we present the NMR solution structure for the Tctex1 dimer from Chlamydomonas axonemal inner dynein arm I1. Structural comparisons reveal a strong similarity with the LC8 dynein light chain dimer, including formation of a strand-switched beta sheet interface. Analysis of the Tctex1 structure enables the dynein intermediate chain binding site to be identified and suggests a mechanism by which cargo proteins might be attached to this microtubule motor complex. Comparison with the alternate dynein light chain rp3 reveals how the specificity of dynein-cargo interactions mediated by these dynein components is achieved. In addition, this structure provides insight into the consequences of the mutations found in the t haplotype forms of this protein.
Collapse
Affiliation(s)
- Hongwei Wu
- Department of Molecular, Microbial, and Structural Biology, 263 Farmington Avenue, Farmington, Connecticut 06030, USA
| | | | | | | |
Collapse
|
22
|
Nikulina K, Patel-King RS, Takebe S, Pfister KK, King SM. The Roadblock light chains are ubiquitous components of cytoplasmic dynein that form homo- and heterodimers. ACTA ACUST UNITED AC 2005; 57:233-45. [PMID: 14752807 DOI: 10.1002/cm.10172] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The Roadblock/LC7 class of light chains associate with the intermediate chains at the base of the soluble dynein particle. In mammals, there are two Roadblock isoforms (Robl1 and Robl2), one of which (Robl2) is differentially expressed in a tissue-dependent manner and is especially prominent in testis. Here we define the alpha helical content of Robl and demonstrate using both the yeast two-hybrid system and in vitro biochemistry that Robl1 and Robl2 are capable of forming homo- and heterodimers. This is the first report of heterodimer formation by any cytoplasmic dynein component, and it further enlarges the number of potential cytoplasmic dynein isoforms available for binding specific cellular cargoes. In addition, we have generated an antibody that specifically recognizes Robl light chains and shows a 5-10 fold preference for Robl2 over Robl1. Using this antibody, we show that Robl is a ubiquitous cytoplasmic dynein component, being found in samples purified from brain, liver, kidney, and testis. Immunofluorescence analysis reveals that Robl is present in punctate organelles in rat neuroblastoma cells. In testis, Robl is found in Leydig cells, spermatocytes, and sperm flagella.
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- Antibody Specificity/immunology
- Blotting, Western
- Brain Chemistry
- Carrier Proteins/chemistry
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Cell Line, Tumor
- Centrifugation, Density Gradient
- Circular Dichroism
- Cloning, Molecular
- DNA, Complementary/genetics
- Dyneins/chemistry
- Dyneins/genetics
- Dyneins/metabolism
- Electrophoresis, Polyacrylamide Gel
- Genes, Reporter/genetics
- Immunohistochemistry
- Isoenzymes/chemistry
- Isoenzymes/genetics
- Isoenzymes/metabolism
- Kidney/chemistry
- Leydig Cells/chemistry
- Liver/chemistry
- Male
- Maltose-Binding Proteins
- Mice
- Microscopy, Fluorescence
- Microtubules/chemistry
- Molecular Sequence Data
- Molecular Weight
- Polymerase Chain Reaction
- Protein Binding
- Protein Structure, Secondary
- Rats
- Recombinant Fusion Proteins/analysis
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/immunology
- Saccharomyces cerevisiae/genetics
- Sequence Homology, Amino Acid
- Spermatozoa/chemistry
- Testis/chemistry
- Two-Hybrid System Techniques
- Vaccination
Collapse
Affiliation(s)
- Karina Nikulina
- Department of Biochemistry, University of Connecticut Health Center, Farmington 06030-3305, USA
| | | | | | | | | |
Collapse
|
23
|
DiBella LM, Sakato M, Patel-King RS, Pazour GJ, King SM. The LC7 light chains of Chlamydomonas flagellar dyneins interact with components required for both motor assembly and regulation. Mol Biol Cell 2004; 15:4633-46. [PMID: 15304520 PMCID: PMC519155 DOI: 10.1091/mbc.e04-06-0461] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2004] [Revised: 07/09/2004] [Accepted: 07/23/2004] [Indexed: 11/11/2022] Open
Abstract
Members of the LC7/Roadblock family of light chains (LCs) have been found in both cytoplasmic and axonemal dyneins. LC7a was originally identified within Chlamydomonas outer arm dynein and associates with this motor's cargo-binding region. We describe here a novel member of this protein family, termed LC7b that is also present in the Chlamydomonas flagellum. Levels of LC7b are reduced approximately 20% in axonemes isolated from strains lacking inner arm I1 and are approximately 80% lower in the absence of the outer arms. When both dyneins are missing, LC7b levels are diminished to <10%. In oda9 axonemal extracts that completely lack outer arms, LC7b copurifies with inner arm I1, whereas in ida1 extracts that are devoid of I1 inner arms it associates with outer arm dynein. We also have observed that some LC7a is present in both isolated axonemes and purified 18S dynein from oda1, suggesting that it is also a component of both the outer arm and inner arm I1. Intriguingly, in axonemal extracts from the LC7a null mutant, oda15, which assembles approximately 30% of its outer arms, LC7b fails to copurify with either dynein, suggesting that it interacts with LC7a. Furthermore, both the outer arm gamma heavy chain and DC2 from the outer arm docking complex completely dissociate after salt extraction from oda15 axonemes. EDC cross-linking of purified dynein revealed that LC7b interacts with LC3, an outer dynein arm thioredoxin; DC2, an outer arm docking complex component; and also with the phosphoprotein IC138 from inner arm I1. These data suggest that LC7a stabilizes both the outer arms and inner arm I1 and that both LC7a and LC7b are involved in multiple intradynein interactions within both dyneins.
Collapse
Affiliation(s)
- Linda M DiBella
- Department of Biochemistry, University of Connecticut Health Center, Farmington, CT 06030-3305, USA
| | | | | | | | | |
Collapse
|
24
|
Avidor-Reiss T, Maer AM, Koundakjian E, Polyanovsky A, Keil T, Subramaniam S, Zuker CS. Decoding cilia function: defining specialized genes required for compartmentalized cilia biogenesis. Cell 2004; 117:527-39. [PMID: 15137945 DOI: 10.1016/s0092-8674(04)00412-x] [Citation(s) in RCA: 405] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2004] [Revised: 04/14/2004] [Accepted: 04/18/2004] [Indexed: 11/28/2022]
Abstract
The evolution of the ancestral eukaryotic flagellum is an example of a cellular organelle that became dispensable in some modern eukaryotes while remaining an essential motile and sensory apparatus in others. To help define the repertoire of specialized proteins needed for the formation and function of cilia, we used comparative genomics to analyze the genomes of organisms with prototypical cilia, modified cilia, or no cilia and identified approximately 200 genes that are absent in the genomes of nonciliated eukaryotes but are conserved in ciliated organisms. Importantly, over 80% of the known ancestral proteins involved in cilia function are included in this small collection. Using Drosophila as a model system, we then characterized a novel family of proteins (OSEGs: outer segment) essential for ciliogenesis. We show that osegs encode components of a specialized transport pathway unique to the cilia compartment and are related to prototypical intracellular transport proteins.
Collapse
Affiliation(s)
- Tomer Avidor-Reiss
- Howard Hughes Medical Institute and Division of Biological Sciences and Department of Neurosciences, University of California at San Diego, La Jolla, CA 92093, USA
| | | | | | | | | | | | | |
Collapse
|
25
|
DiBella LM, Smith EF, Patel-King RS, Wakabayashi KI, King SM. A Novel Tctex2-related Light Chain Is Required for Stability of Inner Dynein Arm I1 and Motor Function in the Chlamydomonas Flagellum. J Biol Chem 2004; 279:21666-76. [PMID: 15020587 DOI: 10.1074/jbc.m313540200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tctex1 and Tctex2 were originally described in mice as putative distorters/sterility factors involved in the non-Mendelian transmission of t haplotypes. Subsequently, these proteins were found to be light chains of both cytoplasmic and axonemal dyneins. We have now identified a novel Tctex2-related protein (Tctex2b) within the Chlamydomonas flagellum. Tctex2b copurifies with inner arm I1 after both sucrose gradient centrifugation and anion exchange chromatography. Unlike the Tctex2 homologue within the outer dynein arm, analysis of a Tctex2b-null strain indicates that this protein is not essential for assembly of inner arm I1. However, a lack of Tctex2b results in an unstable dynein particle that disassembles after high salt extraction from the axoneme. Cells lacking Tctex2b swim more slowly than wild type and exhibit a reduced flagellar beat frequency. Furthermore, using a microtubule sliding assay we observed that dynein motor function is reduced in vitro. These data indicate that Tctex2b is required for the stability of inner dynein arm I1 and wild-type axonemal dynein function.
Collapse
Affiliation(s)
- Linda M DiBella
- Department of Biochemistry, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030-3305, USA
| | | | | | | | | |
Collapse
|
26
|
Sakato M, King SM. Design and regulation of the AAA+ microtubule motor dynein. J Struct Biol 2004; 146:58-71. [PMID: 15037237 DOI: 10.1016/j.jsb.2003.09.026] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2003] [Revised: 09/22/2003] [Indexed: 11/19/2022]
Abstract
Dyneins are highly complex molecular motors that transport their attached cargo towards the minus end of microtubules. These enzymes are required for many essential motile activities within the cytoplasm and also power eukaryotic cilia and flagella. Each dynein contains one or more heavy chain motor units that consist of an N-terminal stem domain that is involved in cargo attachment, and six AAA+ domains (AAA1-6) plus a C-terminal globular segment that are arranged in a heptameric ring. At least one AAA+ domain (AAA1) is capable of ATP binding and hydrolysis, and the available data suggest that one or more additional domains also may bind nucleotide. The ATP-sensitive microtubule binding site is located at the tip of a 10nm coiled coil stalk that emanates from between AAA4 and AAA5. The function of this motor both in the cytoplasm and the flagellum must be tightly regulated in order to result in useful work. Consequently, dyneins also contain a series of additional components that serve to define the cargo-binding properties of the enzyme and which act as sensors to transmit regulatory inputs to the motor units. Here we describe the two basic dynein designs and detail the various regulatory systems that impinge on this motor within the eukaryotic flagellum.
Collapse
Affiliation(s)
- Miho Sakato
- Department of Biochemistry, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030-3305, USA
| | | |
Collapse
|
27
|
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.
Collapse
Affiliation(s)
- Hongmin Qin
- MCDB Dept., Yale University, New Haven, CT 06520, USA
| | | | | | | | | |
Collapse
|
28
|
Abstract
The most studied example of transmission ratio distortion (TRD) in mice is that of the t-complex. This is a variant region of Chromosome 17 which exists as a polymorphism in wild mice. Males heterozygous for a t-haplotype and a normal Chr 17 transmit the t-haplotype to >50% of their young, up to 99%. Homozygous males are sterile. The TRD produced by the t-complex is due to the action of three or more distorter genes (Tcd) on a responder gene (Tcr). t-Haplotypes are maintained intact by crossover suppression induced by four neighboring inversions, the Tcd and Tcr loci lying in different inversions. Sperm formation is normal in t/t males, but sperm function is impaired through gross defects in sperm motility. The responder gene has been identified as a fusion gene formed from a sperm motility kinase and a ribosomal S6 kinase. Three candidate distorter genes have also been identified as genes coding for dynein chains, and thus possibly involved in sperm flagellar function.
Collapse
Affiliation(s)
- Mary F Lyon
- Mammalian Genetics Unit, Medical Research Council, Harwell, Didcot, Oxon OX11 0RD, United Kingdom.
| |
Collapse
|
29
|
Ogawa K, Inaba K. Sperm motility-activating complex formed by t-complex distorters. Biochem Biophys Res Commun 2003; 310:1155-9. [PMID: 14559236 DOI: 10.1016/j.bbrc.2003.09.137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Transmission ratio distortion is a dramatic example of non-Mendelian transmission. In mice, t-haplotype males produce dysfunctional +-sperm and normal t-sperm, leading to transmission in favor of t-sperm. Genetic studies have indicated that the t-complex responder locus, Tcr, rescues t-sperm but not +-sperm from defective products of t-complex distorter loci, Tcds. Light chain 1 (LC1) and LC3 from sea urchin sperm outer arm dynein have sequence similarities to Tctex2 and Tctex1, respectively, both of which are wild-type products of Tcds. We show here that LC1 and LC3 are able to make a 1:1 complex. Since Tcr is a member of the Smok (sperm motility kinase) family and LC1 is phosphorylated at the activation of sperm motility in a cAMP-dependent manner, this complex in a dynein motor molecule might be a direct target of Smok/Tcr kinase in a signal cascade that regulates sperm motility. Thus, we designate it as Smoac (sperm motility activating complex).
Collapse
Affiliation(s)
- Kazuo Ogawa
- Center for Radioisotope Facilities, Okazaki National Research Institutes, Okazaki 444-8585, Japan.
| | | |
Collapse
|
30
|
Neesen J, Drenckhahn JD, Tiede S, Burfeind P, Grzmil M, Konietzko J, Dixkens C, Kreutzberger J, Laccone F, Omran H. Identification of the human ortholog of the t-complex-encoded protein TCTE3 and evaluation as a candidate gene for primary ciliary dyskinesia. Cytogenet Genome Res 2003; 98:38-44. [PMID: 12584439 DOI: 10.1159/000068545] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Primary ciliary dyskinesia (PCD) is a heterogeneous autosomal recessive disease that is caused by impaired ciliary and flagellar functions. About 50% of PCD patients show situs inversus, denoted as Kartagener syndrome. In most cases, axonemal defects in cilia and sperm tails can be demonstrated by electron microscopy, i.e. PCD patients often lack inner and/or outer dynein arms in their sperm tails and cilia, supporting the hypothesis that mutations in dynein genes may cause PCD. In order to identify novel PCD genes we have isolated the human ortholog of the murine TCTE3 gene. The human TCTE3 gene encodes a dynein light chain and shares high similarity to dynein light chains of other species. The TCTE3 gene is expressed in tissues containing cilia or flagella, it is composed of four exons and located on chromosome 6q25-->q27. To elucidate the role of TCTE3 as a candidate gene for PCD a mutational analysis of thirty-six PCD patients was performed. We detected five polymorphisms in the coding sequence and in the 5' UTR of the TCTE3 gene. In one patient a heterozygous nucleotide exchange was identified resulting in an arginine to isoleucine substitution at the amino acid level. However, this exchange was also detected in one control DNA. Our results indicate that mutations in the TCTE3 gene are not a main cause of primary ciliary dyskinesia.
Collapse
Affiliation(s)
- J Neesen
- Institute of Human Genetics, University of Göttingen, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Kamiya R. Functional diversity of axonemal dyneins as studied in Chlamydomonas mutants. INTERNATIONAL REVIEW OF CYTOLOGY 2003; 219:115-55. [PMID: 12211628 DOI: 10.1016/s0074-7696(02)19012-7] [Citation(s) in RCA: 185] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Cilia and flagella of most organisms are equipped with two kinds of motor protein complex, the inner and outer dynein arms. The two arms were previously thought to be similar to each other, but recent studies using Chlamydomonas mutants indicate that they differ significantly in subunit structure and arrangement within the axoneme. For example, whereas the outer dynein arm exists as a single protein complex containing three heavy chains, the inner dynein arm comprises seven different subspecies each containing one or two discrete heavy chains. Furthermore, the two kinds of arms appear to differ in function also. Most strikingly, our studies suggest that inner-arm dynein, but not outer-arm dynein, is under the control of the central pair microtubules and radial spokes. The axoneme thus appears to be equipped with two rather distinct systems for beating: one involving inner-arm dyneins, the central pair and radial spokes, and the other involving outer-arm dynein alone.
Collapse
Affiliation(s)
- Ritsu Kamiya
- Department of Biological Sciences, University of Tokyo, Japan
| |
Collapse
|
32
|
Campbell PK, Waymire KG, Heier RL, Sharer C, Day DE, Reimann H, Jaje JM, Friedrich GA, Burmeister M, Bartness TJ, Russell LD, Young LJ, Zimmer M, Jenne DE, MacGregor GR. Mutation of a Novel Gene Results in Abnormal Development of Spermatid Flagella, Loss of Intermale Aggression and Reduced Body Fat in Mice. Genetics 2002; 162:307-20. [PMID: 12242242 PMCID: PMC1462267 DOI: 10.1093/genetics/162.1.307] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
ROSA22 male mice are sterile due to a recessive gene-trap mutation that affects development of the spermatid flagellum. The defect involves the flagellar axoneme, which becomes unstable around the time of its assembly. Despite a subsequent complete failure in flagellar assembly, development of the spermatid head appears normal and the spermatid head is released at the correct stage in spermatogenesis. The mutation is pleiotropic. Although ROSA22 homozygote males have normal levels of circulating testosterone and display normal mating behavior, they do not exhibit intermale aggressive behavior and have reduced body fat. The mutated gene (Gtrgeo22) maps to mouse chromosome 10 and is closely flanked by two known genes, Madcam1 and Cdc34. Ribonuclease protection analysis indicates that expression of the flanking genes is unaffected by the mutation. Gtrgeo22 is expressed at low levels in epithelial cells in several tissues, as well as in testis and brain. Analysis of the peptide coding sequence suggests that Gtrgeo22 encodes a novel transmembrane protein, which contains dileucine and tyrosine-based motifs involved in intracellular sorting of transmembrane proteins. Analysis of the Gtrgeo22 gene product should provide novel insight into the molecular basis for intermale aggression and sperm flagellar development.
Collapse
|
33
|
Fan JS, Zhang Q, Tochio H, Zhang M. Backbone dynamics of the 8 kDa dynein light chain dimer reveals molecular basis of the protein's functional diversity. JOURNAL OF BIOMOLECULAR NMR 2002; 23:103-114. [PMID: 12153036 DOI: 10.1023/a:1016332918178] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Axonemal and cytoplasmic dyneins share a highly conserved 8 kDa light chain (DLC8) for motor assembly and function. Other than serving as a light chain of dynein complexes, DLC8 has been shown to bind a larger number of proteins with diverse biological functions including cell cycle control, apoptosis, and cell polarity maintenance. Therefore, DLC8 is likely a multifunctional regulatory protein. DLC8 exists as a dimer in solution, and the protein dimer is capable of binding to two target molecules. In this work, the backbone dynamics of DLC8, both in its apo- and target-peptide bound forms, were characterized by 15N NMR relaxation studies. The relaxation data were analyzed using model-free approach. We show that the target peptide-binding region of apo-DLC8 experiences microsecond-to-millisecond time scale conformational fluctuation, suggesting that the target-binding region of the protein is capable of adjusting its shape and size in responding to its various targets. The conformational breathing of the target-binding region of apo-DLC8 was also supported by backbone amide exchange experiment. Such segmental conformational motion of the protein is significantly reduced upon forming a complex with a target peptide. The dynamic properties of DLC8 in solution provide insight into the protein's diverse sequence-dependent target binding.
Collapse
Affiliation(s)
- Jing-Song Fan
- Department of Biochemistry, The Hong Kong University of Science and Technology, Kowloon, PR China
| | | | | | | |
Collapse
|
34
|
Abstract
Chlamydomonas is a biflagellate unicellular green alga that has proven especially amenable for the analysis of microtubule (MT)-based molecular motors, notably dyneins. These enzymes form the inner and outer arms of the flagellum and are also required for intraflagellar transport. Dyneins have masses of approximately 1-2 MDa and consist of up to 15 different polypeptides. Nucleotide binding/hydrolysis and MT motor activity are associated with the heavy chains, and we detail here our current model for the substructural organization of these approximately 520-kDa proteins. The remaining polypeptides play a variety of roles in dynein function, including attachment of the motor to cargo, regulation of motor activity in response to specific inputs, and their necessity for the assembly and/or stability of the entire complex. The combination of genetic, physiological, structural, and biochemical approaches has made the Chlamydomonas flagellum a very powerful model system in which to dissect the function of these fascinating molecular motors.
Collapse
Affiliation(s)
- L M DiBella
- Department of Biochemistry, University of Connecticut Health Center, Farmington 06032, USA
| | | |
Collapse
|
35
|
Rodríguez-Crespo I, Yélamos B, Roncal F, Albar JP, Ortiz de Montellano PR, Gavilanes F. Identification of novel cellular proteins that bind to the LC8 dynein light chain using a pepscan technique. FEBS Lett 2001; 503:135-41. [PMID: 11513870 DOI: 10.1016/s0014-5793(01)02718-1] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Dynein is a minus end-directed microtubule motor that serves multiple cellular functions. We have performed a fine mapping of the 8 kDa dynein light chain (LC8) binding sites throughout the development of a library of consecutive synthetic dodecapeptides covering the amino acid sequences of the various proteins known to interact with this dynein member according to the yeast two hybrid system. Two different consensus sequences were identified: GIQVD present in nNOS, in DNA cytosine methyl transferase and also in GKAP, where it is present twice in the protein sequence. The other LC8 binding motif is KSTQT, present in Bim, dynein heavy chain, Kid-1, protein 4 and also in swallow. Interestingly, this KSTQT motif is also present in several viruses known to associate with microtubules during retrograde transport from the plasma membrane to the nucleus during viral infection.
Collapse
Affiliation(s)
- I Rodríguez-Crespo
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Spain.
| | | | | | | | | | | |
Collapse
|
36
|
DiBella LM, Benashski SE, Tedford HW, Harrison A, Patel-King RS, King SM. The Tctex1/Tctex2 class of dynein light chains. Dimerization, differential expression, and interaction with the LC8 protein family. J Biol Chem 2001; 276:14366-73. [PMID: 11278908 DOI: 10.1074/jbc.m011456200] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Tctex1/Tctex2 family of dynein light chains associates with the intermediate chains at the base of the soluble dynein particle. These components are essential for dynein assembly and participate in specific motor-cargo interactions. To further address the role of these light chains in dynein activity, the structural and biochemical properties of several members of this polypeptide class were examined. Gel filtration chromatography and native gel electrophoresis indicate that recombinant Chlamydomonas flagellar Tctex1 exists as a dimer in solution. Furthermore, yeast two-hybrid analysis suggests that this association also occurs in vivo. In contrast, both murine and Chlamydomonas Tctex2 are monomeric. To investigate protein-protein interactions involving these light chains, outer arm dynein from Chlamydomonas flagella was cross-linked using dimethylpimelimidate. Immunoblot analysis of the resulting products revealed the interaction of LC2 (Tctex2) with LC6, which is closely related to the highly conserved LC8 protein found in many enzyme systems, including dynein. Northern dot blot analysis demonstrated that Tctex1/Tctex2 family light chains are differentially expressed both in a tissue-specific and developmentally regulated manner in humans. These data provide further support for the existence of functionally distinct populations of cytoplasmic dynein with differing light chain content.
Collapse
Affiliation(s)
- L M DiBella
- Department of Biochemistry, University of Connecticut Health Center, Farmington, Connecticut 06030-3305, USA
| | | | | | | | | | | |
Collapse
|
37
|
Pazour GJ, Witman GB. Forward and reverse genetic analysis of microtubule motors in Chlamydomonas. Methods 2000; 22:285-98. [PMID: 11133235 DOI: 10.1006/meth.2000.1081] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The ability to integrate biochemical, cell biological, and genetic approaches makes Chlamydomonas reinhardtii the premier model organism for studies of the eukaryotic flagellum and its associated molecular motors. Hundreds of motility mutations have been identified in Chlamydomonas, including many that affect dyneins and kinesins. These mutations have yielded much information on the structure and function of the motors as well as the roles of individual subunits within the motors. The development of insertional mutagenesis has opened the door to powerful new approaches for genetic analysis in Chlamydomonas. Insertional mutants are created by transforming cells with DNA-containing selectable markers. The DNA is randomly integrated throughout the genome and usually deletes part of the chromosome at the site of insertion, thereby creating mutations that are marked by the integrated DNA. These mutations can be used for forward genetic approaches where one characterizes a mutant phenotype and then clones the relevant gene using the integrated DNA as a tag. The insertional mutants also may be used in a reverse genetic approach in which mutants lacking a gene of interest are identified by DNA hybridization. We describe methods to generate and characterize insertional mutants, using mutations that affect the outer dynein arm as examples.
Collapse
Affiliation(s)
- G J Pazour
- Department of Cell Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA.
| | | |
Collapse
|
38
|
Perrone CA, Myster SH, Bower R, O'Toole ET, Porter ME. Insights into the structural organization of the I1 inner arm dynein from a domain analysis of the 1beta dynein heavy chain. Mol Biol Cell 2000; 11:2297-313. [PMID: 10888669 PMCID: PMC14920 DOI: 10.1091/mbc.11.7.2297] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
To identify domains in the dynein heavy chain (Dhc) required for the assembly of an inner arm dynein, we characterized a new motility mutant (ida2-6) obtained by insertional mutagenesis. ida2-6 axonemes lack the polypeptides associated with the I1 inner arm complex. Recovery of genomic DNA flanking the mutation indicates that the defects are caused by plasmid insertion into the Dhc10 transcription unit, which encodes the 1beta Dhc of the I1 complex. Transformation with Dhc10 constructs encoding <20% of the Dhc can partially rescue the motility defects by reassembly of an I1 complex containing an N-terminal 1beta Dhc fragment and a full-length 1alpha Dhc. Electron microscopic analysis reveals the location of the missing 1beta Dhc motor domain within the axoneme structure. These observations, together with recent studies on the 1alpha Dhc, identify a Dhc domain required for complex assembly and further demonstrate that the intermediate and light chains are associated with the stem regions of the Dhcs in a distinct structural location. The positioning of these subunits within the I1 structure has significant implications for the pathways that target the assembly of the I1 complex into the axoneme and modify the activity of the I1 dynein during flagellar motility.
Collapse
Affiliation(s)
- C A Perrone
- Department of Genetics, Cell Biology, and Development, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
| | | | | | | | | |
Collapse
|
39
|
Pfister KK, Benashski SE, Dillman JF, Patel-King RS, King SM. Identification and molecular characterization of the p24 dynactin light chain. CELL MOTILITY AND THE CYTOSKELETON 2000; 41:154-67. [PMID: 9786090 DOI: 10.1002/(sici)1097-0169(1998)41:2<154::aid-cm6>3.0.co;2-e] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Intracellular transport along microtubules uses the motor proteins cytoplasmic dynein and kinesin. Cytoplasmic dynein is responsible for movement to the minus ends of microtubules and the evidence indicates that dynein interacts with another protein complex, dynactin. In order to better understand how these proteins function, we have sought to identify and clone the subunit polypeptides of these two complexes, in particular their light chains. Dynactin is made up of eight subunits of approximately 24,000 to 160,000 Da. In order to clone the p24 subunit, the components of purified dynactin were resolved by SDS polyacrylamide gel electrophoresis. The amino acid sequence of a tryptic peptide from the 24,000-Mr region of the gel was obtained and a candidate polypeptide identified by a screen of the databases. This polypeptide has a predicted molecular weight of 20,822 Da. Using an antibody to a different region of this protein, we demonstrate that it copurifies with microtubules and elutes from the microtubule pellet with characteristics similar to those of the dynactin complex and distinct from those of cytoplasmic dynein. This polypeptide co-sediments with dynactin on sucrose density gradients and it also co-immunoprecipitates with dynactin, but not with kinesin or cytoplasmic dynein. Together these results demonstrate that this polypeptide is the p24 subunit of dynactin. Analysis of the predicted amino acid sequence of p24 shows that it is a unique protein that has no significant similarity to known enzymes or other proteins. Structural analysis indicates that most of this protein will form an alpha-helix and that portions of the molecule may participate in the formation of coiled-coils. Since stoichiometric analysis of dynactin indicates that there is one molecule of p24 per dynactin complex, these characteristics suggest that this polypeptide may be involved in protein-protein interactions, perhaps in the assembly of the dynactin complex.
Collapse
Affiliation(s)
- K K Pfister
- Department of Cell Biology, University of Virginia Health Science Center, Charlottesville 22908-0439, USA.
| | | | | | | | | |
Collapse
|
40
|
Abstract
Dyneins are large, multisubunit ATPases that interact with microtubules to generate force. Dyneins move eukaryotic cilia and flagella and are in the cytoplasm, where they are involved in the transport of particles and organelles along microtubules and in the transport of condensed chromosomes during mitosis [reviewed in Holzbaur et al., 1994; Gibbons, 1996]. Defects in human axonemal dynein complexes have been shown to be associated with Kartagener's syndrome, which is characterized by recurrent respiratory tract infections, immotile sperm and situs inversus. Cytoplasmic and axonemal dyneins are composed of heavy, intermediate, and light chains. The best characterised groups of dynein genes so far are those encoding cytoplasmic heavy chains and heavy chains from the outer arms from axonemes. These share extensive sequence similarity and are conserved throughout species. Recently, several genes encoding intermediate and light chains have been identified; these have encoded a remarkable diversity of products, which also seem to be highly conserved between species, although they fall into several complex groups. The structure of dynein heavy chain genes, the emerging knowledge on intermediate and light chain genes and their products, and the possible involvement of dyneins in disease are discussed.
Collapse
Affiliation(s)
- I Milisav
- Department of Pathology, University of Cambridge, UK.
| |
Collapse
|
41
|
Abstract
The t haplotype is an ancestral version of proximal mouse chromosome 17 that has evolved mechanisms to persist as an intact genomic variant in mouse populations. t haplotypes contain mutations that affect embryonic development, male fertility and male transmission ratio distortion (TRD). Collectively, these mutations drive the evolutionary success of t haplotypes, a phenomenon that remains one of the longstanding mysteries of mouse genetics. Molecular genetic analysis of TRD has been confounded by inversions that arose to lock together the various elements of this complex trait. Our first molecular glimpse of the TRD mechanism has finally been revealed with the cloning of the t complex responder (Tcr) locus, a chimeric kinase with a genetically cis active effect. Whereas + sperm in a +/t male have impaired flagellar function caused by the deleterious action of trans-active, t-haplotype-encoded 'distorters,' the mutant activity of Tcr counterbalances the distorter effects, maintaining the motility and fertilizing ability of t sperm.
Collapse
Affiliation(s)
- J Schimenti
- The Jackson Laboratory, Bar Harbor, ME 04609, USA.
| |
Collapse
|
42
|
Abstract
Dyneins are large multi-component microtubule-based molecular motors involved in many fundamental cellular processes including vesicular transport, mitosis and ciliary/flagellar beating. In order to achieve useful work, these enzymes must contain motor, cargo-binding and regulatory components. The ATPase and microtubule motor domains are located within the very large dynein heavy chains that form the globular heads and stems of the complex. Cargo-binding activity involves the intermediate chains and several classes of light chain that associate in a subcomplex at the base of the soluble dynein particle. Regulatory control of dynein motor function is thought to involve the phosphorylation of various components as well as a series of light chain proteins that are directly associated with the heavy chains. These latter polypeptides have a variety of intriguing attributes, including redox-sensitive vicinal dithiols and Ca(2+)-binding, suggesting that the activity of individual dyneins may be subject to multiple regulatory inputs. Recent molecular, genetic and structural studies have revealed insight into the roles played by these various components and the mechanisms of dynein-based motility.
Collapse
Affiliation(s)
- S M King
- Department of Biochemistry, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06032-3305, USA.
| |
Collapse
|
43
|
Herrmann BG, Koschorz B, Wertz K, McLaughlin KJ, Kispert A. A protein kinase encoded by the t complex responder gene causes non-mendelian inheritance. Nature 1999; 402:141-6. [PMID: 10647005 DOI: 10.1038/45970] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Males heterozygous for the t-haplotype form of mouse chromosome 17 preferentially transmit the t-chromosome to their progeny. Several distorter/sterility loci carried on the t-haplotype together impair flagellar function in all spermatozoa whereas the responder, Tcr, rescues t-sperm but not wild-type sperm. Thus, t-sperm have an advantage over wild-type sperm in fertilizing egg cells. We have isolated Tcr by positional cloning and show that it is a member of a novel protein kinase gene family, designated Smok, which is expressed late during spermiogenesis. Smok kinases are components of a signal cascade which may control sperm motility. Tcr has a reduced kinase activity, which may allow it to counterbalance a signalling impairment caused by the distorter/sterility loci. Tcr transgene constructs cause non-mendelian transmission of chromosomes on which they are carried, which leads to sex-ratio distortion when Tcr cosegregates with the Y chromosome.
Collapse
Affiliation(s)
- B G Herrmann
- Max-Planck-Institute of Immunobiology, Freiburg, Germany.
| | | | | | | | | |
Collapse
|
44
|
Pazour GJ, Koutoulis A, Benashski SE, Dickert BL, Sheng H, Patel-King RS, King SM, Witman GB. LC2, the chlamydomonas homologue of the t complex-encoded protein Tctex2, is essential for outer dynein arm assembly. Mol Biol Cell 1999; 10:3507-20. [PMID: 10512883 PMCID: PMC25620 DOI: 10.1091/mbc.10.10.3507] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Tctex2 is thought to be one of the distorter genes of the mouse t haplotype. This complex greatly biases the segregation of the chromosome that carries it such that in heterozygous +/t males, the t haplotype is transmitted to >95% of the offspring, a phenomenon known as transmission ratio distortion. The LC2 outer dynein arm light chain of Chlamydomonas reinhardtii is a homologue of the mouse protein Tctex2. We have identified Chlamydomonas insertional mutants with deletions in the gene encoding LC2 and demonstrate that the LC2 gene is the same as the ODA12 gene, the product of which had not been identified previously. Complete deletion of the LC2/ODA12 gene causes loss of all outer arms and a slow jerky swimming phenotype. Transformation of the deletion mutant with the cloned LC2/ODA12 gene restores the outer arms and rescues the motility phenotype. Therefore, LC2 is required for outer arm assembly. The fact that LC2 is an essential subunit of flagellar outer dynein arms allows us to propose a detailed mechanism whereby transmission ratio distortion is explained by the differential binding of mutant (t haplotype encoded) and wild-type dyneins to the axonemal microtubules of t-bearing or wild-type sperm, with resulting differences in their motility.
Collapse
Affiliation(s)
- G J Pazour
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Myster SH, Knott JA, Wysocki KM, O'Toole E, Porter ME. Domains in the 1alpha dynein heavy chain required for inner arm assembly and flagellar motility in Chlamydomonas. J Cell Biol 1999; 146:801-18. [PMID: 10459015 PMCID: PMC2156140 DOI: 10.1083/jcb.146.4.801] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/1999] [Accepted: 07/20/1999] [Indexed: 11/22/2022] Open
Abstract
Flagellar motility is generated by the activity of multiple dynein motors, but the specific role of each dynein heavy chain (Dhc) is largely unknown, and the mechanism by which the different Dhcs are targeted to their unique locations is also poorly understood. We report here the complete nucleotide sequence of the Chlamydomonas Dhc1 gene and the corresponding deduced amino acid sequence of the 1alpha Dhc of the I1 inner dynein arm. The 1alpha Dhc is similar to other axonemal Dhcs, but two additional phosphate binding motifs (P-loops) have been identified in the NH(2)- and COOH-terminal regions. Because mutations in Dhc1 result in motility defects and loss of the I1 inner arm, a series of Dhc1 transgenes were used to rescue the mutant phenotypes. Motile cotransformants that express either full-length or truncated 1alpha Dhcs were recovered. The truncated 1alpha Dhc fragments lacked the dynein motor domain, but still assembled with the 1beta Dhc and other I1 subunits into partially functional complexes at the correct axoneme location. Analysis of the transformants has identified the site of the 1alpha motor domain in the I1 structure and further revealed the role of the 1alpha Dhc in flagellar motility and phototactic behavior.
Collapse
Affiliation(s)
- Steven H. Myster
- Department of Genetics, Cell Biology, and Development, University of Minnesota Medical School, Minneapolis, Minnesota 55455
| | - Julie A. Knott
- Department of Genetics, Cell Biology, and Development, University of Minnesota Medical School, Minneapolis, Minnesota 55455
| | - Katrina M. Wysocki
- Department of Genetics, Cell Biology, and Development, University of Minnesota Medical School, Minneapolis, Minnesota 55455
| | - Eileen O'Toole
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado at Boulder, Boulder, Colorado 80309-0347
| | - Mary E. Porter
- Department of Genetics, Cell Biology, and Development, University of Minnesota Medical School, Minneapolis, Minnesota 55455
| |
Collapse
|
46
|
Abstract
The mouse t-complex, located on chromosome 17, contains genes known to influence male, but not female, fertility. Although some t-complex genes are recessive lethals, t-chromosomes are maintained in the population by transmission ratio distortion. When male mice heterozygous for the t-chromosome mate with wild-type females, most offspring will possess the t-chromosome, indicating a link between t-complex genes and sperm function. Several proteins coded for by t-complex genes have been localised in the sperm flagellum, suggesting roles relating to motility. Another t-complex protein appears able to regulate the adenylyl cyclase/cAMP signal transduction pathway, known to play an important role in capacitation. Defective motility and/or failure to capacitate ("switch on") would result in poorly fertile or infertile spermatozoa. Given the existence of human homologues for many genes in the t-complex and the prevalence of "male factor" infertility, information obtained about the t-complex not only will provide insight into basic biological mechanisms but may be of future clinical relevance as well.
Collapse
Affiliation(s)
- L R Fraser
- Anatomy and Human Biology Group and Developmental Biology Research Centre, London, United Kingdom.
| | | |
Collapse
|
47
|
Inaba K, Kagami O, Ogawa K. Tctex2-related outer arm dynein light chain is phosphorylated at activation of sperm motility. Biochem Biophys Res Commun 1999; 256:177-83. [PMID: 10066443 DOI: 10.1006/bbrc.1999.0309] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
When the motility of sperm is activated, only one light chain of flagellar outer arm dynein is phosphorylated in many organisms. We show here that the light chain to be phosphorylated was shown to be light chain 2 (LC2) in rainbow trout and chum salmon sperm and LC1 in sea urchin sperm. Molecular analyses of the phosphorylated light chains from sperm flagella of the salmonid fishes and sea urchin revealed that the light chains are homologs of the mouse t complex-encoded protein Tctex2, which is one of the putative t complex distorters. These results suggest that mouse Tctex2 might also be a light chain of flagellar outer arm dynein and that the abortive phosphorylation of Tctex2/outer arm dynein light chain might be related to the less progressive movement of sperm.
Collapse
Affiliation(s)
- K Inaba
- Asamushi Marine Biological Station, Tohoku University, Asamushi, Aomori, Aomori, 039-3501, Japan.
| | | | | |
Collapse
|
48
|
Fowkes ME, Mitchell DR. The role of preassembled cytoplasmic complexes in assembly of flagellar dynein subunits. Mol Biol Cell 1998; 9:2337-47. [PMID: 9725897 PMCID: PMC25499 DOI: 10.1091/mbc.9.9.2337] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Previous work has revealed a cytoplasmic pool of flagellar precursor proteins capable of contributing to the assembly of new flagella, but how and where these components assemble is unknown. We tested Chlamydomonas outer-dynein arm subunit stability and assembly in the cytoplasm of wild-type cells and 11 outer dynein arm assembly mutant strains (oda1-oda11) by Western blotting of cytoplasmic extracts, or immunoprecipitates from these extracts, with five outer-row dynein subunit-specific antibodies. Western blots reveal that at least three oda mutants (oda6, oda7, and oda9) alter the level of a subunit that is not the mutant gene product. Immunoprecipitation shows that large preassembled flagellar complexes containing all five tested subunits (three heavy chains and two intermediate chains) exist within wild-type cytoplasm. When the preassembly of these subunits was examined in oda strains, we observed three patterns: complete coassembly (oda 1, 3, 5, 8, and 10), partial coassembly (oda7 and oda11), and no coassembly (oda2, 6, and 9) of the four tested subunits with HCbeta. Our data, together with previous studies, suggest that flagellar outer-dynein arms preassemble into a complete Mr approximately 2 x 10(6) dynein arm that resides in a cytoplasmic precursor pool before transport into the flagellar compartment.
Collapse
Affiliation(s)
- M E Fowkes
- Department of Anatomy and Cell Biology, SUNY Health Science Center, Syracuse, New York 13210, USA
| | | |
Collapse
|
49
|
Campbell KS, Cooper S, Dessing M, Yates S, Buder A. Interaction of p59 fyn Kinase with the Dynein Light Chain, Tctex-1, and Colocalization During Cytokinesis. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.4.1728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The protein tyrosine kinase p59fyn (Fyn) plays important roles in both lymphocyte Ag receptor signaling and cytokinesis of proB cells. We utilized yeast two-hybrid cloning to identify the product of the tctex-1 gene as a protein that specifically interacts with Fyn, but not with other Src family kinases. Tctex-1 was recently identified as a component of the dynein cytoskeletal motor complex. The capacity of a Tctex-1-glutathione S-transferase fusion protein to effectively bind Fyn from cell lysates confirmed the authenticity of this interaction. Tctex-1 binding required the first 19 amino acids of Fyn and integrity of two lysine residues within this sequence that were previously shown to be important for Fyn interactions with the immunoreceptor tyrosine-based activation motifs (ITAMs) of lymphocyte Ag receptors. Expression of tctex-1 mRNA and protein was observed in all lymphoma lines analyzed, and immunofluorescence confocal microscopy localized the protein to the perinuclear region. Analysis of a T cell hybridoma revealed prominent colocalization of Tctex-1 and Fyn at the cleavage furrow and mitotic spindles in cells undergoing cytokinesis. Our results provide a unique insight into a mechanism by which Tctex-1 might mediate specific recruitment of Fyn to the dynein complex in lymphocytes, which may be a critical event in mediating the previously defined role of Fyn in cytokinesis.
Collapse
Affiliation(s)
| | | | - Mark Dessing
- Basel Institute for Immunology, Basel, Switzerland
| | - Sol Yates
- Basel Institute for Immunology, Basel, Switzerland
| | - Annie Buder
- Basel Institute for Immunology, Basel, Switzerland
| |
Collapse
|
50
|
Tai AW, Chuang JZ, Sung CH. Localization of Tctex-1, a cytoplasmic dynein light chain, to the Golgi apparatus and evidence for dynein complex heterogeneity. J Biol Chem 1998; 273:19639-49. [PMID: 9677391 DOI: 10.1074/jbc.273.31.19639] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To date, much attention has been focused on the heavy and intermediate chains of the multisubunit cytoplasmic dynein complex; however, little is known about the localization or function of dynein light chains. In this study, we find that Tctex-1, a light chain of cytoplasmic dynein, localizes predominantly to the Golgi apparatus in interphase fibroblasts. Immunofluorescent staining reveals striking juxtanuclear staining characteristic of the Golgi apparatus as well as nuclear envelope and punctate cytoplasmic staining that often decorates microtubules. Tctex-1 colocalization with Golgi compartment markers, its distribution upon treatment with various pharmacological agents, and the cofractionation of Tctex-1-associated membranes with Golgi membranes are all consistent with a Golgi localization. The distribution of Tctex-1 in interphase cells only partially overlaps with the dynein intermediate chain and p150(Glued) upon immunofluorescence, but most of Tctex-1 is redistributed onto mitotic spindles along with other dynein/dynactin subunits. Using sequential immunoprecipitations, we demonstrate that there is a subset of Tctex-1 not associated with the intermediate chain at steady state; the converse also appears to be true. Distinct populations of dynein complexes are likely to exist, and such diversity may occur in part at the level of their light chain compositions.
Collapse
Affiliation(s)
- A W Tai
- Department of Cell Biology and Anatomy, Margaret M. Dyson Vision Research Institute, Cornell University Medical College, New York, New York 10021, USA
| | | | | |
Collapse
|