scholarly journals SUMOylation of human septins is critical for septin filament bundling and cytokinesis

2017 ◽  
Vol 216 (12) ◽  
pp. 4041-4052 ◽  
Author(s):  
David Ribet ◽  
Serena Boscaini ◽  
Clothilde Cauvin ◽  
Martin Siguier ◽  
Serge Mostowy ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Posttranslational Modification ◽  
Diffusion Barriers ◽  
Cytoskeletal Proteins ◽  
Cellular Functions ◽  
Terminal Domain ◽  
Subcellular Compartmentalization ◽  
Protein Recruitment ◽  
Septin Filament

Septins are cytoskeletal proteins that assemble into nonpolar filaments. They are critical in diverse cellular functions, acting as scaffolds for protein recruitment and as diffusion barriers for subcellular compartmentalization. Human septins are encoded by 13 different genes and are classified into four groups based on sequence homology (SEPT2, SEPT3, SEPT6, and SEPT7 groups). In yeast, septins were among the first proteins reported to be modified by SUMOylation, a ubiquitin-like posttranslational modification. However, whether human septins could be modified by small ubiquitin-like modifiers (SUMOs) and what roles this modification may have in septin function remains unknown. In this study, we first show that septins from all four human septin groups can be covalently modified by SUMOs. We show in particular that endogenous SEPT7 is constitutively SUMOylated during the cell cycle. We then map SUMOylation sites to the C-terminal domain of septins belonging to the SEPT6 and SEPT7 groups and to the N-terminal domain of septins from the SEPT3 group. We finally demonstrate that expression of non-SUMOylatable septin variants from the SEPT6 and SEPT7 groups leads to aberrant septin bundle formation and defects in cytokinesis after furrow ingression. Altogether, our results demonstrate a pivotal role for SUMOylation in septin filament bundling and cell division.

scholarly journals Par6α Interacts with the Dynactin Subunit p150Glued and Is a Critical Regulator of Centrosomal Protein Recruitment

2010 ◽  
Vol 21 (19) ◽  
pp. 3376-3385 ◽  
Author(s):  
Andrew Kodani ◽  
Vinh Tonthat ◽  
Beibei Wu ◽  
Christine Sütterlin
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Protein Delivery ◽  
Protein Transport ◽  
Protein Composition ◽  
Microtubule Cytoskeleton ◽  
Centrosomal Protein ◽  
Cycle Dependent ◽  
Protein Recruitment

The centrosome contains proteins that control the organization of the microtubule cytoskeleton in interphase and mitosis. Its protein composition is tightly regulated through selective and cell cycle–dependent recruitment, retention, and removal of components. However, the mechanisms underlying protein delivery to the centrosome are not completely understood. We describe a novel function for the polarity protein Par6α in protein transport to the centrosome. We detected Par6α at the centrosome and centriolar satellites where it interacted with the centriolar satellite protein PCM-1 and the dynactin subunit p150Glued. Depletion of Par6α caused the mislocalization of p150Glued and centrosomal components that are critical for microtubule anchoring at the centrosome. As a consequence, there were severe alterations in the organization of the microtubule cytoskeleton in the absence of Par6α and cell division was blocked. We propose a model in which Par6α controls centrosome organization through its association with the dynactin subunit p150Glued.

scholarly journals Regulation of Cell Division in Bacteria by Monitoring Genome Integrity and DNA Replication Status

2019 ◽  
Vol 202 (2) ◽  
Author(s):  
Peter E. Burby ◽  
Lyle A. Simmons
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Division ◽  
Dna Replication ◽  
Cell Cycle Progression ◽  
Genome Instability ◽  
Sos Response ◽  
Bacterial Cells ◽  
Cycle Progression ◽  
Content Type

ABSTRACT All organisms regulate cell cycle progression by coordinating cell division with DNA replication status. In eukaryotes, DNA damage or problems with replication fork progression induce the DNA damage response (DDR), causing cyclin-dependent kinases to remain active, preventing further cell cycle progression until replication and repair are complete. In bacteria, cell division is coordinated with chromosome segregation, preventing cell division ring formation over the nucleoid in a process termed nucleoid occlusion. In addition to nucleoid occlusion, bacteria induce the SOS response after replication forks encounter DNA damage or impediments that slow or block their progression. During SOS induction, Escherichia coli expresses a cytoplasmic protein, SulA, that inhibits cell division by directly binding FtsZ. After the SOS response is turned off, SulA is degraded by Lon protease, allowing for cell division to resume. Recently, it has become clear that SulA is restricted to bacteria closely related to E. coli and that most bacteria enforce the DNA damage checkpoint by expressing a small integral membrane protein. Resumption of cell division is then mediated by membrane-bound proteases that cleave the cell division inhibitor. Further, many bacterial cells have mechanisms to inhibit cell division that are regulated independently from the canonical LexA-mediated SOS response. In this review, we discuss several pathways used by bacteria to prevent cell division from occurring when genome instability is detected or before the chromosome has been fully replicated and segregated.

scholarly journals Anticancer potential of nitric oxide (NO) in neuroblastoma treatment

RSC Advances ◽  
2021 ◽  
Vol 11 (16) ◽  
pp. 9112-9120
Author(s):  
Jenna L. Gordon ◽  
Kristin J. Hinsen ◽  
Melissa M. Reynolds ◽  
Tyler A. Smith ◽  
Haley O. Tucker ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cell Cycle ◽  
Cell Division ◽  
Cell Viability ◽  
Cell Cycle Arrest ◽  
Neuroblastoma Cells ◽  
Cycle Arrest

S-Nitrosoglutathione (GSNO) reduces cell viability, inhibits cell division, and induces cell cycle arrest and apoptosis in neuroblastoma cells.

scholarly journals In-Frame and Frameshift Mutations in Zebrafish presenilin 2 Affect Different Cellular Functions in Young Adult Brains

2021 ◽  
pp. 1-10
Author(s):  
Karissa Barthelson ◽  
Stephen Martin Pederson ◽  
Morgan Newman ◽  
Haowei Jiang ◽  
Michael Lardelli
Keyword(s):  
Cell Cycle ◽  
Young Adult ◽  
Oxidative Phosphorylation ◽  
Frameshift Mutation ◽  
Long Term Potentiation ◽  
Cellular Functions ◽  
Reading Frame ◽  
Term Potentiation ◽  
Presenilin 2

Background: Mutations in PRESENILIN 2 (PSEN2) cause early onset familial Alzheimer’s disease (EOfAD) but their mode of action remains elusive. One consistent observation for all PRESENILIN gene mutations causing EOfAD is that a transcript is produced with a reading frame terminated by the normal stop codon—the “reading frame preservation rule”. Mutations that do not obey this rule do not cause the disease. The reasons for this are debated. Objective: To predict cellular functions affected by heterozygosity for a frameshift, or a reading frame-preserving mutation in zebrafish psen2 using bioinformatic techniques. Methods: A frameshift mutation (psen2N140fs) and a reading frame-preserving (in-frame) mutation (psen2T141 _ L142delinsMISLISV) were previously isolated during genome editing directed at the N140 codon of zebrafish psen2 (equivalent to N141 of human PSEN2). We mated a pair of fish heterozygous for each mutation to generate a family of siblings including wild type and heterozygous mutant genotypes. Transcriptomes from young adult (6 months) brains of these genotypes were analyzed. Results: The in-frame mutation uniquely caused subtle, but statistically significant, changes to expression of genes involved in oxidative phosphorylation, long-term potentiation and the cell cycle. The frameshift mutation uniquely affected genes involved in Notch and MAPK signaling, extracellular matrix receptor interactions and focal adhesion. Both mutations affected ribosomal protein gene expression but in opposite directions. Conclusion: A frameshift and an in-frame mutation at the same position in zebrafish psen2 cause discrete effects. Changes in oxidative phosphorylation, long-term potentiation and the cell cycle may promote EOfAD pathogenesis in humans.

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