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La-related protein 6 controls ciliated cell differentiation.
Title
La-related protein 6 controls ciliated cell differentiation.
Creator
Manojlovic, Zarko, Earwood, Ryan, Kato, Akiko, Perez, Diana, Cabrera, Oscar A, Didier, Ruth, Megraw, Timothy L, Stefanovic, Branko, Kato, Yoichi
Abstract/Description
La-related protein 6 (LARP6) is an evolutionally conserved RNA-binding protein. Vertebrate LARP6 binds the 5' stem-loop found in mRNAs encoding type I collagen to regulate their translation, but other target mRNAs and additional functions for LARP6 are unknown. The aim of this study was to elucidate an additional function of LARP6 and to evaluate the importance of its function during development. To uncover the role of LARP6 in development, we utilized Morpholino Oligos to deplete LARP6...
Show moreLa-related protein 6 (LARP6) is an evolutionally conserved RNA-binding protein. Vertebrate LARP6 binds the 5' stem-loop found in mRNAs encoding type I collagen to regulate their translation, but other target mRNAs and additional functions for LARP6 are unknown. The aim of this study was to elucidate an additional function of LARP6 and to evaluate the importance of its function during development. To uncover the role of LARP6 in development, we utilized Morpholino Oligos to deplete LARP6 protein in Xenopus embryos. Then, embryonic phenotypes and ciliary structures of LAPR6 morphants were examined. To identify the molecular mechanism underlying ciliogenesis regulated by LARP6, we tested the expression level of cilia-related genes, which play important roles in ciliogenesis, by RT-PCR or whole mount in situ hybridization (WISH). We knocked down LARP6 in Xenopus embryos and found neural tube closure defects. LARP6 mutant, which compromises the collagen synthesis, could rescue these defects. Neural tube closure defects are coincident with lack of cilia, antenna-like cellular organelles with motility- or sensory-related functions, in the neural tube. The absence of cilia at the epidermis was also observed in LARP6 morphants, and this defect was due to the absence of basal bodies which are formed from centrioles and required for ciliary assembly. In the process of multi-ciliated cell (MCC) differentiation, mcidas, which activates the transcription of genes required for centriole formation during ciliogenesis, could partially restore MCCs in LARP6 morphants. In addition, LARP6 likely controls the expression of mcidas in a Notch-independent manner. La-related protein 6 is involved in ciliated cell differentiation during development by controlling the expression of cilia-related genes including mcidas. This LARP6 function involves a mechanism that is distinct from its established role in binding to collagen mRNAs and regulating their translation.
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Date Issued
2017-03-23
Identifier
FSU_pmch_28344782, 10.1186/s13630-017-0047-7, PMC5364628, 28344782, 28344782, 47
Format
Citation
Drosophila melanogaster as a model for basal body research.
Title
Drosophila melanogaster as a model for basal body research.
Creator
Jana, Swadhin Chandra, Bettencourt-Dias, Mónica, Durand, Bénédicte, Megraw, Timothy L
Abstract/Description
The fruit fly, Drosophila melanogaster, is one of the most extensively studied organisms in biological research and has centrioles/basal bodies and cilia that can be modelled to investigate their functions in animals generally. Centrioles are nine-fold symmetrical microtubule-based cylindrical structures required to form centrosomes and also to nucleate the formation of cilia and flagella. When they function to template cilia, centrioles transition into basal bodies. The fruit fly has various...
Show moreThe fruit fly, Drosophila melanogaster, is one of the most extensively studied organisms in biological research and has centrioles/basal bodies and cilia that can be modelled to investigate their functions in animals generally. Centrioles are nine-fold symmetrical microtubule-based cylindrical structures required to form centrosomes and also to nucleate the formation of cilia and flagella. When they function to template cilia, centrioles transition into basal bodies. The fruit fly has various types of basal bodies and cilia, which are needed for sensory neuron and sperm function. Genetics, cell biology and behaviour studies in the fruit fly have unveiled new basal body components and revealed different modes of assembly and functions of basal bodies that are conserved in many other organisms, including human, green algae and plasmodium. Here we describe the various basal bodies of Drosophila, what is known about their composition, structure and function.
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Date Issued
2016-07-05
Identifier
FSU_pmch_27382461, 10.1186/s13630-016-0041-5, PMC4932733, 27382461, 27382461, 41
Format
Citation
Seckel syndrome and centrosomal protein Ninein localizes asymmetrically to stem cell centrosomes but is not required for normal development, behavior, or DNA damage response in Drosophila.
Title
The Seckel syndrome and centrosomal protein Ninein localizes asymmetrically to stem cell centrosomes but is not required for normal development, behavior, or DNA damage response in Drosophila.
Creator
Zheng, Yiming, Mennella, Vito, Marks, Steven, Wildonger, Jill, Elnagdi, Esraa, Agard, David, Megraw, Timothy L
Abstract/Description
Ninein (Nin) is a centrosomal protein whose gene is mutated in Seckel syndrome (SCKL, MIM 210600), an inherited recessive disease that results in primordial dwarfism, cognitive deficiencies, and increased sensitivity to genotoxic stress. Nin regulates neural stem cell self-renewal, interkinetic nuclear migration, and microtubule assembly in mammals. Nin is evolutionarily conserved, yet its role in cell division and development has not been investigated in a model organism. Here we...
Show moreNinein (Nin) is a centrosomal protein whose gene is mutated in Seckel syndrome (SCKL, MIM 210600), an inherited recessive disease that results in primordial dwarfism, cognitive deficiencies, and increased sensitivity to genotoxic stress. Nin regulates neural stem cell self-renewal, interkinetic nuclear migration, and microtubule assembly in mammals. Nin is evolutionarily conserved, yet its role in cell division and development has not been investigated in a model organism. Here we characterize the single Nin orthologue in Drosophila Drosophila Nin localizes to the periphery of the centrosome but not at centriolar structures as in mammals. However, Nin shares the property of its mammalian orthologue of promoting microtubule assembly. In neural and germline stem cells, Nin localizes asymmetrically to the younger (daughter) centrosome, yet it is not required for the asymmetric division of stem cells. In wing epithelia and muscle, Nin localizes to noncentrosomal microtubule-organizing centers. Surprisingly, loss of nin expression from a nin mutant does not significantly affect embryonic and brain development, fertility, or locomotor performance of mutant flies or their survival upon exposure to DNA-damaging agents. Although it is not essential, our data suggest that Nin plays a supportive role in centrosomal and extracentrosomal microtubule organization and asymmetric stem cell division.
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Date Issued
2016-06-01
Identifier
FSU_pmch_27053665, 10.1091/mbc.E15-09-0655, PMC4884065, 27053665, 27053665, mbc.E15-09-0655
Format
Citation
Rootletin organizes the ciliary rootlet to achieve neuron sensory function in Drosophila.
Title
Rootletin organizes the ciliary rootlet to achieve neuron sensory function in Drosophila.
Creator
Chen, Jieyan V, Kao, Ling-Rong, Jana, Swadhin C, Sivan-Loukianova, Elena, Mendonça, Susana, Cabrera, Oscar A, Singh, Priyanka, Cabernard, Clemens, Eberl, Daniel F, Bettencourt...
Show moreChen, Jieyan V, Kao, Ling-Rong, Jana, Swadhin C, Sivan-Loukianova, Elena, Mendonça, Susana, Cabrera, Oscar A, Singh, Priyanka, Cabernard, Clemens, Eberl, Daniel F, Bettencourt-Dias, Monica, Megraw, Timothy L
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Abstract/Description
Cilia are essential for cell signaling and sensory perception. In many cell types, a cytoskeletal structure called the ciliary rootlet links the cilium to the cell body. Previous studies indicated that rootlets support the long-term stability of some cilia. Here we report that Drosophila melanogaster Rootletin (Root), the sole orthologue of the mammalian paralogs Rootletin and C-Nap1, assembles into rootlets of diverse lengths among sensory neuron subtypes. Root mutant neurons lack rootlets...
Show moreCilia are essential for cell signaling and sensory perception. In many cell types, a cytoskeletal structure called the ciliary rootlet links the cilium to the cell body. Previous studies indicated that rootlets support the long-term stability of some cilia. Here we report that Drosophila melanogaster Rootletin (Root), the sole orthologue of the mammalian paralogs Rootletin and C-Nap1, assembles into rootlets of diverse lengths among sensory neuron subtypes. Root mutant neurons lack rootlets and have dramatically impaired sensory function, resulting in behavior defects associated with mechanosensation and chemosensation. Root is required for cohesion of basal bodies, but the cilium structure appears normal in Root mutant neurons. We show, however, that normal rootlet assembly requires centrioles. The N terminus of Root contains a conserved domain and is essential for Root function in vivo. Ectopically expressed Root resides at the base of mother centrioles in spermatocytes and localizes asymmetrically to mother centrosomes in neuroblasts, both requiring Bld10, a basal body protein with varied functions.
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Date Issued
2015-10-26
Identifier
FSU_pmch_26483560, 10.1083/jcb.201502032, PMC4621839, 26483560, 26483560, jcb.201502032
Format
Citation
TGF-β Signaling Regulates the Differentiation of Motile Cilia.
Title
TGF-β Signaling Regulates the Differentiation of Motile Cilia.
Creator
Tözser, Janos, Earwood, Ryan, Kato, Akiko, Brown, Jacob, Tanaka, Koichi, Didier, Ruth, Megraw, Timothy L, Blum, Martin, Kato, Yoichi
Abstract/Description
The cilium is a small cellular organelle with motility- and/or sensory-related functions that plays a crucial role during developmental and homeostatic processes. Although many molecules or signal transduction pathways that control cilia assembly have been reported, the mechanisms of ciliary length control have remained enigmatic. Here, we report that Smad2-dependent transforming growth factor β (TGF-β) signaling impacts the length of motile cilia at the Xenopus left-right (LR) organizer, the...
Show moreThe cilium is a small cellular organelle with motility- and/or sensory-related functions that plays a crucial role during developmental and homeostatic processes. Although many molecules or signal transduction pathways that control cilia assembly have been reported, the mechanisms of ciliary length control have remained enigmatic. Here, we report that Smad2-dependent transforming growth factor β (TGF-β) signaling impacts the length of motile cilia at the Xenopus left-right (LR) organizer, the gastrocoel roof plate (GRP), as well as at the neural tube and the epidermis. Blocking TGF-β signaling resulted in the absence of the transition zone protein B9D1/MSKR-1 from cilia in multi-ciliated cells (MCCs) of the epidermis. Interestingly, this TGF-β activity is not mediated by Mcidas, Foxj1, and RFX2, the known major regulators of ciliogenesis. These data indicate that TGF-β signaling is crucial for the function of the transition zone, which in turn may affect the regulation of cilia length.
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Date Issued
2015-05-19
Identifier
FSU_pmch_25959824, 10.1016/j.celrep.2015.04.025, PMC4439334, 25959824, 25959824, S2211-1247(15)00412-X
Format
Citation
Spermitin
Title
Spermitin: a novel mitochondrial protein in Drosophila spermatids..
Creator
Chen, Jieyan V, Megraw, Timothy L
Abstract/Description
Mitochondria, important energy centers in the cell, also control sperm cell morphogenesis. Drosophila spermatids have a remarkably large mitochondrial formation called the nebenkern. Immediately following meiosis during sperm development, the mitochondria in the spermatid fuse together into two large aggregates which then wrap around one another to produce the spherical nebenkern: a giant mitochondrion about 6 micrometers in diameter. The fused mitochondria play an important role in sperm...
Show moreMitochondria, important energy centers in the cell, also control sperm cell morphogenesis. Drosophila spermatids have a remarkably large mitochondrial formation called the nebenkern. Immediately following meiosis during sperm development, the mitochondria in the spermatid fuse together into two large aggregates which then wrap around one another to produce the spherical nebenkern: a giant mitochondrion about 6 micrometers in diameter. The fused mitochondria play an important role in sperm tail elongation by providing a structural platform to support the elongation of sperm cells. We have identified a novel testis-specific protein, Spermitin (Sprn), a protein with a Pleckstrin homology-like (PH) domain related to Ran-binding protein 1 at its C-terminus. Fluorescence microscopy showed that Sprn localizes at mitochondria in transfected Kc167 cells, and in the nebenkern throughout spermatid morphogenesis. The role of Sprn is unclear, as sprn mutant males are fertile, and have sperm tail length comparable to the wild-type.
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Date Issued
2014-09-29
Identifier
FSU_pmch_25265054, 10.1371/journal.pone.0108802, PMC4181656, 25265054, 25265054, PONE-D-14-12211
Format
Citation
Drosophila pericentrin requires interaction with calmodulin for its function at centrosomes and neuronal basal bodies but not at sperm basal bodies.
Title
Drosophila pericentrin requires interaction with calmodulin for its function at centrosomes and neuronal basal bodies but not at sperm basal bodies.
Creator
Galletta, Brian J, Guillen, Rodrigo X, Fagerstrom, Carey J, Brownlee, Chris W, Lerit, Dorothy A, Megraw, Timothy L, Rogers, Gregory C, Rusan, Nasser M
Abstract/Description
Pericentrin is a critical centrosomal protein required for organizing pericentriolar material (PCM) in mitosis. Mutations in pericentrin cause the human genetic disorder Majewski/microcephalic osteodysplastic primordial dwarfism type II, making a detailed understanding of its regulation extremely important. Germaine to pericentrin's function in organizing PCM is its ability to localize to the centrosome through the conserved C-terminal PACT domain. Here we use Drosophila pericentrin-like...
Show morePericentrin is a critical centrosomal protein required for organizing pericentriolar material (PCM) in mitosis. Mutations in pericentrin cause the human genetic disorder Majewski/microcephalic osteodysplastic primordial dwarfism type II, making a detailed understanding of its regulation extremely important. Germaine to pericentrin's function in organizing PCM is its ability to localize to the centrosome through the conserved C-terminal PACT domain. Here we use Drosophila pericentrin-like-protein (PLP) to understand how the PACT domain is regulated. We show that the interaction of PLP with calmodulin (CaM) at two highly conserved CaM-binding sites in the PACT domain controls the proper targeting of PLP to the centrosome. Disrupting the PLP-CaM interaction with single point mutations renders PLP inefficient in localizing to centrioles in cultured S2 cells and Drosophila neuroblasts. Although levels of PCM are unaffected, it is highly disorganized. We also demonstrate that basal body formation in the male testes and the production of functional sperm does not rely on the PLP-CaM interaction, whereas production of functional mechanosensory neurons does.
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Date Issued
2014-09-15
Identifier
FSU_pmch_25031429, 10.1091/mbc.E13-10-0617, PMC4161505, 25031429, 25031429, mbc.E13-10-0617
Format
Citation
Cdk5rap2 exposes the centrosomal root of microcephaly syndromes.
Title
Cdk5rap2 exposes the centrosomal root of microcephaly syndromes.
Creator
Megraw, Timothy L, Sharkey, James T, Nowakowski, Richard S
Abstract/Description
Autosomal recessive primary microcephaly (MCPH) is characterized by small brain size as a result of deficient neuron production in the developing cerebral cortex. Although MCPH is a rare disease, the questions surrounding its etiology strike at the core of stem cell biology. The seven genes implicated in MCPH all encode centrosomal proteins and disruption of the MCPH gene Cdk5rap2 in mice revealed its role in neural progenitor proliferation and in maintaining normal centriole replication...
Show moreAutosomal recessive primary microcephaly (MCPH) is characterized by small brain size as a result of deficient neuron production in the developing cerebral cortex. Although MCPH is a rare disease, the questions surrounding its etiology strike at the core of stem cell biology. The seven genes implicated in MCPH all encode centrosomal proteins and disruption of the MCPH gene Cdk5rap2 in mice revealed its role in neural progenitor proliferation and in maintaining normal centriole replication control. We discuss here the impact that centrosome regulation has upon neural progenitors in the developing brain. We integrate the impact of centriole replication defects with the functions of Cdk5rap2 and other MCPH proteins, propose mechanisms for progenitor loss in MCPH, and discuss links to two other microcephaly syndromes.
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Date Issued
2011-08-01
Identifier
FSU_pmch_21632253, 10.1016/j.tcb.2011.04.007, PMC3371655, 21632253, 21632253, S0962-8924(11)00083-3
Format
Citation