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Cells Jan 2020The duplication cycle is the fascinating process that, starting from a cell, results in the formation of two daughter cells and it is essential for life. Cytokinesis is... (Review)
Review
The duplication cycle is the fascinating process that, starting from a cell, results in the formation of two daughter cells and it is essential for life. Cytokinesis is the final step of the cell cycle, it is a very complex phase, and is a concert of forces, remodeling, trafficking, and cell signaling. All of the steps of cell division must be properly coordinated with each other to faithfully segregate the genetic material and this task is fundamental for generating viable cells. Given the importance of this process, molecular pathways and proteins that are involved in cytokinesis are conserved from yeast to humans. In this review, we describe symmetric and asymmetric cell division in animal cell and in a model organism, budding yeast. In addition, we illustrate the surveillance mechanisms that ensure a proper cell division and discuss the connections with normal cell proliferation and organs development and with the occurrence of human diseases.
Topics: Animals; Asymmetric Cell Division; Cell Cycle Checkpoints; Cytokinesis; Eukaryotic Cells; Health; Humans; Models, Biological
PubMed: 31979090
DOI: 10.3390/cells9020271 -
ELife Jun 2023As a cell changes size during the cell cycle, why does its density remain constant?
As a cell changes size during the cell cycle, why does its density remain constant?
Topics: Cell Cycle; Cell Division
PubMed: 37314067
DOI: 10.7554/eLife.89415 -
Current Biology : CB May 2021As the interface between the cell and its environment, the cell cortex must be able to respond to a variety of external stimuli. This is made possible in part by...
As the interface between the cell and its environment, the cell cortex must be able to respond to a variety of external stimuli. This is made possible in part by cortical excitability, a behavior driven by coupled positive and negative feedback loops that generate propagating waves of actin assembly in the cell cortex. Cortical excitability is best known for promoting cell protrusion and allowing the interpretation of and response to chemoattractant gradients in migrating cells. It has recently become apparent, however, that cortical excitability is involved in the response of the cortex to internal signals from the cell-cycle regulatory machinery and the spindle during cell division. Two overlapping functions have been ascribed to cortical excitability in cell division: control of cell division plane placement, and amplification of the activity of the small GTPase Rho at the equatorial cortex during cytokinesis. Here, we propose that cortical excitability explains several important yet poorly understood features of signaling during cell division. We also consider the potential advantages that arise from the use of cortical excitability as a signaling mechanism to regulate cortical dynamics in cell division.
Topics: Actins; Cell Division; Cytokinesis; Cytoplasm; Signal Transduction
PubMed: 34033789
DOI: 10.1016/j.cub.2021.02.053 -
ELife Feb 2021A new imaging approach can distinguish between cells destined to stop proliferating and those committed to re-entering the cell cycle in live animals.
A new imaging approach can distinguish between cells destined to stop proliferating and those committed to re-entering the cell cycle in live animals.
Topics: Animals; Cell Cycle; Cell Division
PubMed: 33576741
DOI: 10.7554/eLife.66591 -
International Journal of Molecular... Apr 2024Skin aging is a complex process involving structural and functional changes and is characterized by a decrease in collagen content, reduced skin thickness, dryness, and... (Review)
Review
Skin aging is a complex process involving structural and functional changes and is characterized by a decrease in collagen content, reduced skin thickness, dryness, and the formation of wrinkles. This process is underpinned by multiple mechanisms including the free radical theory, inflammation theory, photoaging theory, and metabolic theory. The skin immune system, an indispensable part of the body's defense mechanism, comprises macrophages, lymphocytes, dendritic cells, and mast cells. These cells play a pivotal role in maintaining skin homeostasis and responding to injury or infection. As age advances, along with various internal and external environmental stimuli, skin immune cells may undergo senescence or accelerated aging, characterized by reduced cell division capability, increased mortality, changes in gene expression patterns and signaling pathways, and altered immune cell functions. These changes collectively impact the overall function of the immune system. This review summarizes the relationship between skin aging and immunity and explores the characteristics of skin aging, the composition and function of the skin immune system, the aging of immune cells, and the effects of these cells on immune function and skin aging. Immune dysfunction plays a significant role in skin aging, suggesting that immunoregulation may become one of the important strategies for the prevention and treatment of skin aging.
Topics: Skin Aging; Skin; Mast Cells; Cell Division
PubMed: 38612909
DOI: 10.3390/ijms25074101 -
Biochemical Society Transactions Apr 2024Malaria, a vector borne disease, is a major global health and socioeconomic problem caused by the apicomplexan protozoan parasite Plasmodium. The parasite alternates... (Review)
Review
Malaria, a vector borne disease, is a major global health and socioeconomic problem caused by the apicomplexan protozoan parasite Plasmodium. The parasite alternates between mosquito vector and vertebrate host, with meiosis in the mosquito and proliferative mitotic cell division in both hosts. In the canonical eukaryotic model, cell division is either by open or closed mitosis and karyokinesis is followed by cytokinesis; whereas in Plasmodium closed mitosis is not directly accompanied by concomitant cell division. Key molecular players and regulatory mechanisms of this process have been identified, but the pivotal role of certain protein complexes and the post-translational modifications that modulate their actions are still to be deciphered. Here, we discuss recent evidence for the function of known proteins in Plasmodium cell division and processes that are potential novel targets for therapeutic intervention. We also identify key questions to open new and exciting research to understand divergent Plasmodium cell division.
Topics: Plasmodium; Cell Division; Animals; Humans; Malaria; Protozoan Proteins; Mitosis; Cytokinesis; Meiosis; Protein Processing, Post-Translational; Host-Parasite Interactions
PubMed: 38563493
DOI: 10.1042/BST20230403 -
Biology of the Cell Dec 2020The spindle is crucial for cell division by allowing the faithful segregation of replicated chromosomes to daughter cells. Proper segregation is ensured only if... (Review)
Review
The spindle is crucial for cell division by allowing the faithful segregation of replicated chromosomes to daughter cells. Proper segregation is ensured only if microtubules (MTs) and hundreds of other associated factors interact to assemble this complex structure with the appropriate architecture and size. In this review, we describe the latest view of spindle organisation as well as the molecular gradients and mechanisms underlying MT nucleation and spindle assembly. We then discuss the overlapping physical and molecular constraints that dictate spindle morphology, concluding with a focus on spindle size regulation.
Topics: Animals; Cell Line; Humans; M Phase Cell Cycle Checkpoints; Microtubules; Spindle Apparatus
PubMed: 32762076
DOI: 10.1111/boc.202000065 -
ELife May 2023Aurora B, together with IN-box, the C-terminal part of INCENP, forms an enzymatic complex that ensures faithful cell division. The [Aurora B/IN-box] complex is activated...
Aurora B, together with IN-box, the C-terminal part of INCENP, forms an enzymatic complex that ensures faithful cell division. The [Aurora B/IN-box] complex is activated by autophosphorylation in the Aurora B activation loop and in IN-box, but it is not clear how these phosphorylations activate the enzyme. We used a combination of experimental and computational studies to investigate the effects of phosphorylation on the molecular dynamics and structure of [Aurora B/IN-box]. In addition, we generated partially phosphorylated intermediates to analyze the contribution of each phosphorylation independently. We found that the dynamics of Aurora and IN-box are interconnected, and IN-box plays both positive and negative regulatory roles depending on the phosphorylation status of the enzyme complex. Phosphorylation in the activation loop of Aurora B occurs intramolecularly and prepares the enzyme complex for activation, but two phosphorylated sites are synergistically responsible for full enzyme activity.
Topics: Aurora Kinase B; Allosteric Regulation; Amino Acid Sequence; Cell Division; Phosphorylation; Mitosis
PubMed: 37227118
DOI: 10.7554/eLife.85328 -
Cellular & Molecular Biology Letters Apr 2022Autophagy plays an essential role in maintaining cellular homeostasis and in the response to cellular stress. Autophagy is also involved in cell cycle progression, yet...
BACKGROUND
Autophagy plays an essential role in maintaining cellular homeostasis and in the response to cellular stress. Autophagy is also involved in cell cycle progression, yet the relationship between these processes is not clearly defined.
RESULTS
In exploring this relationship, we observed that the inhibition of autophagy impaired the G2/M phase-arresting activity of etoposide but enhanced the G1 phase-arresting activity of palbociclib. We further investigated the connection of basal autophagy and cell cycle by utilizing the autophagosome tracer dye Cyto-ID in two ways. First, we established a double-labeling flow-cytometric procedure with Cyto-ID and the DNA probe DRAQ5, permitting the cell cycle phase-specific determination of autophagy in live cells. This approach demonstrated that different cell cycle phases were associated with different autophagy levels: G1-phase cells had the lowest level, and G2/M-phase cells had the highest one. Second, we developed a flow-cytometric cell-sorting procedure based on Cyto-ID that separates cell populations into fractions with low, medium, and high autophagy. Cell cycle analysis of Cyto-ID-sorted cells confirmed that the high-autophagy fraction contained a much higher percentage of G2/M-phase cells than the low-autophagy fraction. In addition, Cyto-ID-based cell sorting also proved to be useful for assessing other autophagy-related processes: extracellular flux analysis revealed metabolic differences between the cell populations, with higher autophagy being associated with higher respiration, higher mitochondrial ATP production, and higher glycolysis.
CONCLUSION
This work provides clear evidence of high autophagy in G2/M-phase cells by establishing a novel cell sorting technique based on Cyto-ID.
Topics: Autophagy; Cell Cycle; Cell Division; G1 Phase; Humans; Leukemia
PubMed: 35382734
DOI: 10.1186/s11658-022-00334-8 -
The Journal of Cell Biology Dec 2019Abscission, the final stage of cell division, requires well-orchestrated changes in endocytic trafficking, microtubule severing, actin clearance, and the physical... (Review)
Review
Abscission, the final stage of cell division, requires well-orchestrated changes in endocytic trafficking, microtubule severing, actin clearance, and the physical sealing of the daughter cell membranes. These processes are highly regulated, and any missteps in localized membrane and cytoskeleton dynamics often lead to a delay or a failure in cell division. The midbody, a microtubule-rich structure that forms during cytokinesis, is a key regulator of abscission and appears to function as a signaling platform coordinating cytoskeleton and endosomal dynamics during the terminal stages of cell division. It was long thought that immediately following abscission and the conclusion of cell division, the midbody is either released or rapidly degraded by one of the daughter cells. Recently, the midbody has gained prominence for exerting postmitotic functions. In this review, we detail the role of the midbody in orchestrating abscission, as well as discuss the relatively new field of postabscission midbody biology, particularly focusing on how it may act to regulate cell polarity and its potential to regulate cell tumorigenicity or stemness.
Topics: Actins; Animals; Cell Division; Cell Line, Tumor; Cell Membrane; Cell Polarity; Cell Proliferation; Cytokinesis; Cytoskeleton; Endocytosis; Endosomal Sorting Complexes Required for Transport; Endosomes; HeLa Cells; Humans; Microtubules; Mitosis; Neoplasms; Phagocytes; Signal Transduction; Spindle Apparatus; Stem Cells
PubMed: 31690620
DOI: 10.1083/jcb.201906148