scholarly journals A complex containing the Sm protein CAR-1 and the RNA helicase CGH-1 is required for embryonic cytokinesis in Caenorhabditis elegans

2005 ◽  
Vol 171 (2) ◽  
pp. 267-279 ◽  
Author(s):  
Anjon Audhya ◽  
Francie Hyndman ◽  
Ian X. McLeod ◽  
Amy S. Maddox ◽  
John R. Yates ◽  
...  
Keyword(s):  
Cell Division ◽  
Caenorhabditis Elegans ◽  
Rna Binding ◽  
Rna Binding Protein ◽  
Rna Helicase ◽  
Aurora B ◽  
Aurora B Kinase ◽  
Daughter Cells ◽  
Sm Protein ◽  
Spindle Structure

Cytokinesis completes cell division and partitions the contents of one cell to the two daughter cells. Here we characterize CAR-1, a predicted RNA binding protein that is implicated in cytokinesis. CAR-1 localizes to germline-specific RNA-containing particles and copurifies with the essential RNA helicase, CGH-1, in an RNA-dependent fashion. The atypical Sm domain of CAR-1, which directly binds RNA, is dispensable for CAR-1 localization, but is critical for its function. Inhibition of CAR-1 by RNA-mediated depletion or mutation results in a specific defect in embryonic cytokinesis. This cytokinesis failure likely results from an anaphase spindle defect in which interzonal microtubule bundles that recruit Aurora B kinase and the kinesin, ZEN-4, fail to form between the separating chromosomes. Depletion of CGH-1 results in sterility, but partially depleted worms produce embryos that exhibit the CAR-1–depletion phenotype. Cumulatively, our results suggest that CAR-1 functions with CGH-1 to regulate a specific set of maternally loaded RNAs that is required for anaphase spindle structure and cytokinesis.

scholarly journals Coordinated regulation of the ESCRT-III component CHMP4C by the chromosomal passenger complex and centralspindlin during cytokinesis

Open Biology ◽  
2016 ◽  
Vol 6 (10) ◽  
pp. 160248 ◽  
Author(s):  
Luisa Capalbo ◽  
Ioanna Mela ◽  
Maria Alba Abad ◽  
A. Arockia Jeyaprakash ◽  
J. Michael Edwardson ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Cell Division ◽  
Aurora B ◽  
Aurora B Kinase ◽  
Chromosomal Passenger Complex ◽  
Force Microscopy ◽  
Daughter Cells ◽  
Atomic Force ◽  
Chromosomal Passenger

The chromosomal passenger complex (CPC)—composed of Aurora B kinase, Borealin, Survivin and INCENP—surveys the fidelity of genome segregation throughout cell division. The CPC has been proposed to prevent polyploidy by controlling the final separation (known as abscission) of the two daughter cells via regulation of the ESCRT-III CHMP4C component. The molecular details are, however, still unclear. Using atomic force microscopy, we show that CHMP4C binds to and remodels membranes in vitro . Borealin prevents the association of CHMP4C with membranes, whereas Aurora B interferes with CHMP4C's membrane remodelling activity. Moreover, we show that CHMP4C phosphorylation is not required for its assembly into spiral filaments at the abscission site and that two distinctly localized pools of phosphorylated CHMP4C exist during cytokinesis. We also characterized the CHMP4C interactome in telophase cells and show that the centralspindlin complex associates preferentially with unphosphorylated CHMP4C in cytokinesis. Our findings indicate that gradual dephosphorylation of CHMP4C triggers a ‘relay’ mechanism between the CPC and centralspindlin that regulates the timely distribution and activation of CHMP4C for the execution of abscission.

scholarly journals Endopolyploidy in irradiated p53-deficient tumour cell lines: Persistence of cell division activity in giant cells expressing Aurora-B kinase

2008 ◽  
Vol 32 (9) ◽  
pp. 1044-1056 ◽  
Author(s):  
Jekaterina Erenpreisa ◽  
Andrei Ivanov ◽  
Sally P. Wheatley ◽  
Elizabeth A. Kosmacek ◽  
Fiorenza Ianzini ◽  
...  
Keyword(s):  
Cell Division ◽  
Cell Lines ◽  
Tumour Cell ◽  
Giant Cells ◽  
Aurora B ◽  
Aurora B Kinase ◽  
Tumour Cell Lines

scholarly journals The Dynamics of P Granule Liquid Droplets Are Regulated by the Caenorhabditis elegans Germline RNA Helicase GLH-1 via Its ATP Hydrolysis Cycle

Genetics ◽  
2020 ◽  
Vol 215 (2) ◽  
pp. 421-434 ◽  
Author(s):  
Wenjun Chen ◽  
Yabing Hu ◽  
Charles F. Lang ◽  
Jordan S. Brown ◽  
Sierra Schwabach ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Cell Fate ◽  
Rna Binding ◽  
Atp Hydrolysis ◽  
Rna Binding Proteins ◽  
Rna Helicase ◽  
Liquid Droplets ◽  
P Granules ◽  
Link Type ◽  
Show Evidence

P granules are phase-separated liquid droplets that play important roles in the maintenance of germ cell fate in Caenorhabditis elegans. Both the localization and formation of P granules are highly dynamic, but mechanisms that regulate such processes remain poorly understood. Here, we show evidence that the VASA-like germline RNA helicase GLH-1 couples distinct steps of its ATPase hydrolysis cycle to control the formation and disassembly of P granules. In addition, we found that the phenylalanine-glycine-glycine repeats in GLH-1 promote its localization at the perinucleus. Proteomic analyses of the GLH-1 complex with a GLH-1 mutation that interferes with P granule disassembly revealed transient interactions of GLH-1 with several Argonautes and RNA-binding proteins. Finally, we found that defects in recruiting the P granule component PRG-1 to perinuclear foci in the adult germline correlate with the fertility defects observed in various GLH-1 mutants. Together, our results highlight the versatile roles of an RNA helicase in controlling the formation of liquid droplets in space and time.

scholarly journals The RNA binding protein Larp1 regulates cell division, apoptosis and cell migration

2010 ◽  
Vol 38 (16) ◽  
pp. 5542-5553 ◽  
Author(s):  
C. Burrows ◽  
N. Abd Latip ◽  
S.-J. Lam ◽  
L. Carpenter ◽  
K. Sawicka ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cell Division ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein

scholarly journals Multiple Mechanisms Inactivate the LIN-41 RNA-Binding Protein to Ensure A Robust Oocyte-to-Embryo Transition in Caenorhabditis elegans

2018 ◽  
Author(s):  
Caroline A. Spike ◽  
Gabriela Huelgas-Morales ◽  
Tatsuya Tsukamoto ◽  
David Greenstein
Keyword(s):  
Caenorhabditis Elegans ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Adaptor Protein ◽  
Protein Translation ◽  
Translational Repression ◽  
Meiotic Maturation ◽  
Oocyte Growth ◽  
Translational Repressor

ABSTRACTIn the nematode Caenorhabditis elegans, the conserved LIN-41 RNA-binding protein is a translational repressor that coordinately controls oocyte growth and meiotic maturation. LIN-41 exerts these effects, at least in part, by preventing the premature activation of the cyclin-dependent kinase CDK-1. Here we investigate the mechanism by which LIN-41 is rapidly eliminated upon the onset of meiotic maturation. Elimination of LIN-41 requires the activities of CDK-1 and multiple SCF-type ubiquitin ligase subunits, including the conserved substrate adaptor protein SEL-10/Fbw7/Cdc4, suggesting that LIN-41 is a target of ubiquitin-mediated protein degradation. Within the LIN-41 protein, two non-overlapping regions, Deg-A and Deg-B, are individually necessary for LIN-41 degradation; both contain several potential phosphodegron sequences, and at least one of these sites is required for LIN-41 degradation. Finally, Deg-A and Deg-B are sufficient, in combination, to mediate SEL-10-dependent degradation when transplanted into a different oocyte protein. Although LIN-41 is a potent inhibitor of protein translation and M-phase entry, the failure to eliminate LIN-41 from early embryos does not result in the continued translational repression of LIN-41 oocyte mRNA targets. Based on these observations, we propose a molecular model for the elimination of LIN-41 by SCFSEL-10 and suggest that LIN-41 is inactivated before it is degraded. Furthermore, we provide evidence that another RNA-binding protein, the GLD-1 tumor suppressor, is regulated similarly. Redundant mechanisms to extinguish translational repression by RNA-binding proteins may both control and provide robustness to irreversible developmental transitions, including meiotic maturation and the oocyte-to-embryo transition.

scholarly journals Substrate Specificity of the TRAMP Nuclear Surveillance Complexes

2020 ◽  
Author(s):  
Clémentine Delan-Forino ◽  
Christos Spanos ◽  
Juri Rappsilber ◽  
David Tollervey
Keyword(s):  
Gene Expression ◽  
Mass Spectrometry ◽  
Binding Sites ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Rna Binding Protein ◽  
Rna Helicase ◽  
Nuclear Rna ◽  
Rna Exosome

ABSTRACTDuring nuclear surveillance in yeast, the RNA exosome functions together with the TRAMP complexes. These include the DEAH-box RNA helicase Mtr4 together with an RNA-binding protein (Air1 or Air2) and a poly(A) polymerase (Trf4 or Trf5). To better determine how RNA substrates are targeted, we analyzed protein and RNA interactions for TRAMP components. Mass spectrometry identified three distinct TRAMP complexes formed in vivo. These complexes preferentially assemble on different classes of transcripts. Unexpectedly, on many substrates, including pre-rRNAs and pre-mRNAs, binding specificity was apparently conferred by Trf4 and Trf5. Clustering of mRNAs by TRAMP association showed co-enrichment for mRNAs with functionally related products, supporting the significance of surveillance in regulating gene expression. We compared binding sites of TRAMP components with multiple nuclear RNA binding proteins, revealing preferential colocalization of subsets of factors. TRF5 deletion reduced Mtr4 recruitment and increased RNA abundance for mRNAs specifically showing high Trf5 binding.

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