scholarly journals PICH function is required for organization of SUMOylated proteins on mitotic chromosomes

2020 ◽  
Author(s):  
Victoria A. Hassebroek ◽  
Hyewon Park ◽  
Nootan Pandey ◽  
Brooklyn T. Lerbakken ◽  
Vasilisa Aksenova ◽  
...  
Keyword(s):  
Chromosome Segregation ◽  
Cell Function ◽  
Mitotic Chromosomes ◽  
Binding Ability ◽  
Chromosomal Proteins ◽  
Chromosome Bridge ◽  
Summary Statement ◽  
Chromosome Bridges ◽  
Dna Translocase

AbstractProper chromosome segregation is essential for faithful cell division and if not maintained results in defective cell function caused by abnormal distribution of genetic information. Polo-like kinase 1 interacting checkpoint helicase (PICH) is a DNA translocase essential in chromosome bridge resolution during mitosis. Its function in resolving chromosome bridges requires both DNA translocase activity and ability to bind chromosomal proteins modified by Small Ubiquitin-like modifier (SUMO). However, it is unclear how these activities are cooperating to resolve chromosome bridges. Here, we show that PICH specifically promotes the organization of SUMOylated proteins like SUMOylated TopoisomeraseIIα (TopoIIα) on mitotic chromosomes. Conditional depletion of PICH using the Auxin Inducible Degron (AID) system resulted in the retention of SUMOylated chromosomal proteins, including TopoIIα, indicating that PICH functions to control proper association of these proteins with chromosomes. Replacement of PICH with its mutants showed that PICH is required for the proper organization of SUMOylated proteins on chromosomes. In vitro assays showed that PICH specifically attenuates SUMOylated TopoIIα activity using its SUMO-binding ability. Taken together, we propose a novel function of PICH in remodeling SUMOylated proteins to ensure faithful chromosome segregation.Summary StatementPolo-like kinase interacting checkpoint helicase (PICH) interacts with SUMOylated proteins to mediate proper chromosome segregation during mitosis. The results demonstrate that PICH controls association of SUMOylated chromosomal proteins, including Topoisomerase IIα, and that function requires PICH translocase activity and SUMO binding ability.

scholarly journals PICH promotes SUMOylated TopoisomeraseIIα dissociation from mitotic centromeres for proper chromosome segregation

2019 ◽  
Author(s):  
Victoria Hassebroek ◽  
Hyewon Park ◽  
Nootan Pandey ◽  
Brooklyn T. Lerbakken ◽  
Vasilisa Aksenova ◽  
...  
Keyword(s):  
Chromosome Segregation ◽  
Binding Protein ◽  
Binding Activity ◽  
Mitotic Chromosomes ◽  
Summary Statement ◽  
Dna Translocase

AbstractPolo-like kinase interacting checkpoint helicase (PICH) is a SNF2 family DNA translocase and is a Small Ubiquitin-like modifier (SUMO) binding protein. Despite that both translocase activity and SUMO-binding activity are required for proper chromosome segregation, how these two activities function to mediate chromosome segregation remains unknown. Here, we show that PICH specifically promotes dissociation of SUMOylated TopoisomeraseIIα (TopoIIα) from mitotic chromosomes. When TopoIIα is stalled by treatment of cells with a potent TopoII inhibitor, ICRF-193, TopoIIα becomes SUMOylated, and this promotes its interaction with PICH. Conditional depletion of PICH using the Auxin Inducible Degron (AID) system resulted in retention of SUMOylated TopoIIα on chromosomes, indicating that PICH removes stalled SUMOylated TopoIIα from chromosomes. In vitro assays showed that PICH specifically regulates SUMOylated TopoIIα activity using its SUMO-binding and translocase activities. Taken together, we propose a novel mechanism for how PICH acts on stalled SUMOylated TopoIIα for proper chromosome segregation.Summary StatementPolo-like kinase interacting checkpoint helicase (PICH) interacts with SUMOylated proteins to mediate proper chromosome segregation during mitosis. The results demonstrate that PICH promotes dissociation of SUMOylated TopoisomeraseIIα from chromosomes and that function leads to proper chromosome segregation.

Simple topology: FtsK-directed recombination at the dif site

2013 ◽  
Vol 41 (2) ◽  
pp. 595-600 ◽  
Author(s):  
Ian Grainge
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Chromosome Segregation ◽  
Motor Domain ◽  
Site Specific ◽  
Multifunctional Protein ◽  
Supercoiled Plasmid ◽  
C Terminus ◽  
Dna Translocase

FtsK is a multifunctional protein, which, in Escherichia coli, co-ordinates the essential functions of cell division, DNA unlinking and chromosome segregation. Its C-terminus is a DNA translocase, the fastest yet characterized, which acts as a septum-localized DNA pump. FtsK's C-terminus also interacts with the XerCD site-specific recombinases which act at the dif site, located in the terminus region. The motor domain of FtsK is an active translocase in vitro, and, when incubated with XerCD and a supercoiled plasmid containing two dif sites, recombination occurs to give unlinked circular products. Despite years of research the mechanism for this novel form of topological filter remains unknown.

scholarly journals PICH regulates the abundance and localization of SUMOylated proteins on mitotic chromosomes

2020 ◽  
Vol 31 (23) ◽  
pp. 2537-2556
Author(s):  
Victoria A. Hassebroek ◽  
Hyewon Park ◽  
Nootan Pandey ◽  
Brooklyn T. Lerbakken ◽  
Vasilisa Aksenova ◽  
...  
Keyword(s):  
Chromosome Segregation ◽  
Mitotic Chromosomes ◽  
Binding Ability ◽  
Topoisomerase Iia

Polo-like kinase-interacting checkpoint helicase (PICH) interacts with SUMOylated proteins to mediate proper chromosome segregation during mitosis. The results demonstrate that PICH controls the association of SUMOylated proteins, including topoisomerase IIa, with chromosomes, requiring PICH translocase activity and SUMO-binding ability.

The Escherichia coli DNA translocase FtsK

2010 ◽  
Vol 38 (2) ◽  
pp. 395-398 ◽  
Author(s):  
David J. Sherratt ◽  
Lidia K. Arciszewska ◽  
Estelle Crozat ◽  
James E. Graham ◽  
Ian Grainge
Keyword(s):  
Escherichia Coli ◽  
Chromosome Segregation ◽  
Regulatory Domain ◽  
Biological Functions ◽  
Comparable Rate ◽  
Site Specific ◽  
Late Stages ◽  
Dna Translocase

Escherichia coli FtsK is a septum-located DNA translocase that co-ordinates the late stages of cytokinesis and chromosome segregation. Relatives of FtsK are present in most bacteria; in Bacillus subtilis, the FtsK orthologue, SpoIIIE, transfers the majority of a chromosome into the forespore during sporulation. DNA translocase activity is contained within a ~ 512-amino-acid C-terminal domain, which is divided into three subdomains: α, β and γ. α and β comprise the translocation motor, and γ is a regulatory domain that interacts with DNA and with the XerD recombinase. In vitro rates of translocation of ~ 5 kb·s−1 have been measured for both FtsK and SpoIIIE, whereas, in vivo, SpoIIIE has a comparable rate of translocation. Translocation by both of these proteins is not only rapid, but also directed by DNA sequence. This directionality requires interaction of the γ subdomain with specific 8 bp DNA asymmetric sequences that are oriented co-directionally with replication direction of the bacterial chromosome. The γ subdomain also interacts with the XerCD site-specific recombinase to activate chromosome unlinking by recombination at the chromosomal dif site. In the present paper, the properties in vivo and in vitro of FtsK and its relatives are discussed in relation to the biological functions of these remarkable enzymes.

scholarly journals NEK2A Interacts with MAD1 and Possibly Functions as a Novel Integrator of the Spindle Checkpoint Signaling

2004 ◽  
Vol 279 (19) ◽  
pp. 20049-20057 ◽  
Author(s):  
Yang Lou ◽  
Jianhui Yao ◽  
Arzhang Zereshki ◽  
Zhen Dou ◽  
Kashif Ahmed ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Chromosome Segregation ◽  
Leucine Zipper ◽  
Spindle Checkpoint ◽  
Mitotic Checkpoint ◽  
Checkpoint Signaling ◽  
C Terminus ◽  
Chromosome Bridge

Chromosome segregation in mitosis is orchestrated by protein kinase signaling cascades. A biochemical cascade named spindle checkpoint ensures the spatial and temporal order of chromosome segregation during mitosis. Here we report that spindle checkpoint protein MAD1 interacts with NEK2A, a human orthologue of theAspergillus nidulansNIMA kinase. MAD1 interacts with NEK2Ain vitroandin vivovia a leucine zipper-containing domain located at the C terminus of MAD1. Like MAD1, NEK2A is localized to HeLa cell kinetochore of mitotic cells. Elimination of NEK2A by small interfering RNA does not arrest cells in mitosis but causes aberrant premature chromosome segregation. NEK2A is required for MAD2 but not MAD1, BUB1, and HEC1 to associate with kinetochores. These NEK2A-eliminated or -suppressed cells display a chromosome bridge phenotype with sister chromatid inter-connected. Moreover, loss of NEK2A impairs mitotic checkpoint signaling in response to spindle damage by nocodazole, which affected mitotic escape and led to generation of cells with multiple nuclei. Our data demonstrate that NEK2A is a kinetochore-associated protein kinase essential for faithful chromosome segregation. We hypothesize that NEK2A links MAD2 molecular dynamics to spindle checkpoint signaling.

scholarly journals The Genotoxicity of Vitamin C in vitro

2008 ◽  
Vol 8 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Hilada Nefić
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Chromosome Segregation ◽  
Human Lymphocytes ◽  
Genotoxic Effects ◽  
Multipolar Spindles ◽  
Index Value ◽  
Chromosome Bridges ◽  
Spindle Function

The genotoxic effects of Vitamin C (ascorbic acid) on human lymphocytes in vitro were estimated by analyzing and identifying various chromosome abnormalities, in relation to the concentration of Vitamin C. Testing concentrations of Vitamin C induced different aberrations including the impairment of spindle function. The spindle disturbances can result in mitotic arrest, multipolar spindles and multipolar segregation, errors in chromosome segregation, formation of chromosome bridges and chromosome laggards. The most frequent irregularities were found in anaphase and telophase. A certain number of lymphocytes were arrested at anaphase or telophase (in colchicine-untreated cultures of human lymphocytes). Testing concentrations of ascorbic acid did not induce a significant increase in the number of aneuploid mitoses and were not clastogenic except at the highest concentration (1,000 μg/ml) in colchicine-treated cultures, and in colchicine-untreated cultures of human lymphocytes the pulverization of chromosome was observed. Vitamin C changed the mitotic index value of lymphocytes notably at the higher concentrations (250, 500 and 1,000 μg/ml).

scholarly journals Effect of memantine, an anti-Alzheimer’s drug, on rodent microglial cells in vitro

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Toru Murakawa-Hirachi ◽  
Yoshito Mizoguchi ◽  
Masahiro Ohgidani ◽  
Yoshinori Haraguchi ◽  
Akira Monji
Keyword(s):  
Neuronal Death ◽  
Phagocytic Activity ◽  
Microglial Cell ◽  
Cell Function ◽  
Microglial Cells ◽  
Phagocytosis Assay ◽  
Intracellular Ca ◽  
Β Amyloid ◽  
The Brain

AbstractThe pathophysiology of Alzheimer’s disease (AD) is related to neuroinflammatory responses mediated by microglia. Memantine, an antagonist of N-methyl-d-aspartate (NMDA) receptors used as an anti-Alzheimer’s drug, protects from neuronal death accompanied by suppression of proliferation and activation of microglial cells in animal models of AD. However, it remains to be tested whether memantine can directly affect microglial cell function. In this study, we examined whether pretreatment with memantine affects intracellular NO and Ca2+ mobilization using DAF-2 and Fura-2 imaging, respectively, and tested the effects of memantine on phagocytic activity by human β-Amyloid (1–42) phagocytosis assay in rodent microglial cells. Pretreatment with memantine did not affect production of NO or intracellular Ca2+ elevation induced by TNF in rodent microglial cells. Pretreatment with memantine also did not affect the mRNA expression of pro-inflammatory (TNF, IL-1β, IL-6 and CD45) or anti-inflammatory (IL-10, TGF-β and arginase) phenotypes in rodent microglial cells. In addition, pretreatment with memantine did not affect the amount of human β-Amyloid (1–42) phagocytosed by rodent microglial cells. Moreover, we observed that pretreatment with memantine did not affect 11 major proteins, which mainly function in the phagocytosis and degradation of β-Amyloid (1–42), including TREM2, DAP12 and neprilysin in rodent microglial cells. To the best of our knowledge, this is the first report to suggest that memantine does not directly modulate intracellular NO and Ca2+ mobilization or phagocytic activity in rodent microglial cells. Considering the neuroinflammation hypothesis of AD, the results might be important to understand the effect of memantine in the brain.

In Vitro PAH-Binding Ability of Lactobacillus brevis TD4

2021 ◽  
pp. 1-17
Author(s):  
Mojtaba Yousefi ◽  
Nasim Khorshidian ◽  
Hedayat Hosseini
Keyword(s):  
Lactobacillus Brevis ◽  
Binding Ability
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