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Journal of Genetics and Genomics = Yi... Apr 2019Most cellular processes descend into failure during aging. While a large collection of longevity pathways has been identified in the past decades, the mechanism for... (Review)
Review
Most cellular processes descend into failure during aging. While a large collection of longevity pathways has been identified in the past decades, the mechanism for age-related decline of cellular homeostasis and organelle function remains largely unsolved. It is known that many organelles undergo structural and functional changes during normal aging, which significantly contributes to the decline of tissue function at old ages. Since recent studies have revealed an emerging role of organelles as regulatory hubs in maintaining cellular homeostasis, understanding of organelle aging will provide important insights into the cellular basis of organismal aging. Here we review current progress on the characterization of age-dependent structural and functional alterations in the more well-studied organelles, as well as the known mechanisms governing organelle aging in model organisms, with a special focus on the fruit fly Drosophila melanogaster.
Topics: Aging; Animals; Drosophila melanogaster; Humans; Organelles
PubMed: 31080045
DOI: 10.1016/j.jgg.2019.03.011 -
Advances in Parasitology 2020Giardia lamblia is a widespread parasitic protist with a complex MT cytoskeleton that is critical for motility, attachment, mitosis and cell division, and transitions... (Review)
Review
Giardia lamblia is a widespread parasitic protist with a complex MT cytoskeleton that is critical for motility, attachment, mitosis and cell division, and transitions between its two life cycle stages-the infectious cyst and flagellated trophozoite. Giardia trophozoites have both highly dynamic and highly stable MT organelles, including the ventral disc, eight flagella, the median body and the funis. The ventral disc, an elaborate MT organelle, is essential for the parasite's attachment to the intestinal villi to avoid peristalsis. Giardia's four flagellar pairs enable swimming motility and may also promote attachment. They are maintained at different equilibrium lengths and are distinguished by their long cytoplasmic regions and novel extra-axonemal structures. The functions of the median body and funis, MT organelles unique to Giardia, remain less understood. In addition to conserved MT-associated proteins, the genome is enriched in ankyrins, NEKs, and novel hypothetical proteins that also associate with the MT cytoskeleton. High-resolution ultrastructural imaging and a current inventory of more than 300 proteins associated with Giardia's MT cytoskeleton lay the groundwork for future mechanistic analyses of parasite attachment to the host, motility, cell division, and encystation/excystation. Giardia's unique MT organelles exemplify the capacity of MT polymers to generate intricate structures that are diverse in both form and function. Thus, beyond its relevance to pathogenesis, the study of Giardia's MT cytoskeleton informs basic cytoskeletal biology and cellular evolution. With the availability of new molecular genetic tools to disrupt gene function, we anticipate a new era of cytoskeletal discovery in Giardia.
Topics: Giardia; Microtubules; Organelles
PubMed: 32122531
DOI: 10.1016/bs.apar.2019.11.001 -
Seminars in Cell & Developmental Biology Jan 2023During early embryogenesis, as cells divide in the developing embryo, the size of intracellular organelles generally decreases to scale with the decrease in overall cell... (Review)
Review
During early embryogenesis, as cells divide in the developing embryo, the size of intracellular organelles generally decreases to scale with the decrease in overall cell size. Organelle size scaling is thought to be important to establish and maintain proper cellular function, and defective scaling may lead to impaired development and disease. However, how the cell regulates organelle size and organization are largely unanswered questions. In this review, we summarize the process of size scaling at both the cell and organelle levels and discuss recently discovered mechanisms that regulate this process during early embryogenesis. In addition, we describe how some recently developed techniques and Xenopus as an animal model can be used to investigate the underlying mechanisms of size regulation and to uncover the significance of proper organelle size scaling and organization.
Topics: Animals; Organelle Size; Xenopus laevis; Cell Size; Organelles
PubMed: 35148938
DOI: 10.1016/j.semcdb.2022.02.002 -
Cell Mar 2017Interconnectivity and feedback control are hallmarks of biological systems. This includes communication between organelles, which allows them to function and adapt to... (Review)
Review
Interconnectivity and feedback control are hallmarks of biological systems. This includes communication between organelles, which allows them to function and adapt to changing cellular environments. While the specific mechanisms for all communications remain opaque, unraveling the wiring of organelle networks is critical to understand how biological systems are built and why they might collapse, as occurs in aging. A comprehensive understanding of all the routes involved in inter-organelle communication is still lacking, but important themes are beginning to emerge, primarily in budding yeast. These routes are reviewed here in the context of sub-system proteostasis and complex adaptive systems theory.
Topics: Aging; Animals; Cell Division; Humans; Organelles; Proteins; Saccharomyces cerevisiae; Signal Transduction
PubMed: 28340346
DOI: 10.1016/j.cell.2017.02.030 -
Genes & Development Apr 2021Our cells are comprised of billions of proteins, lipids, and other small molecules packed into their respective subcellular organelles, with the daunting task of... (Review)
Review
Our cells are comprised of billions of proteins, lipids, and other small molecules packed into their respective subcellular organelles, with the daunting task of maintaining cellular homeostasis over a lifetime. However, it is becoming increasingly evident that organelles do not act as autonomous discrete units but rather as interconnected hubs that engage in extensive communication through membrane contacts. In the last few years, our understanding of how these contacts coordinate organelle function has redefined our view of the cell. This review aims to present novel findings on the cellular interorganelle communication network and how its dysfunction may contribute to aging and neurodegeneration. The consequences of disturbed interorganellar communication are intimately linked with age-related pathologies. Given that both aging and neurodegenerative diseases are characterized by the concomitant failure of multiple cellular pathways, coordination of organelle communication and function could represent an emerging regulatory mechanism critical for long-term cellular homeostasis. We anticipate that defining the relationships between interorganelle communication, aging, and neurodegeneration will open new avenues for therapeutics.
Topics: Animals; Cellular Senescence; Humans; Neurodegenerative Diseases; Organelles; Signal Transduction
PubMed: 33861720
DOI: 10.1101/gad.346759.120 -
International Review of Cell and... 2018Long considered inert fat storage depots, it has become clear that lipid droplets (LDs) are bona fide organelles. Like other organelles, they have a characteristic... (Review)
Review
Long considered inert fat storage depots, it has become clear that lipid droplets (LDs) are bona fide organelles. Like other organelles, they have a characteristic complement of proteins and lipids, and undergo a life cycle that includes biogenesis, maturation, interactions with other organelles, and turnover. I will discuss recent insights into mechanisms governing the life cycle of LDs, and compare and contrast the LD life cycle with that of other metabolic organelles such as mitochondria, peroxisomes, and autophagosomes, highlighting open questions in the field.
Topics: Animals; Humans; Lipid Droplets; Organelles
PubMed: 29551163
DOI: 10.1016/bs.ircmb.2017.12.007 -
Neuron Aug 2022The defining evolutionary feature of eukaryotic cells is the emergence of membrane-bound organelles. Compartmentalization allows each organelle to maintain a spatially,... (Review)
Review
The defining evolutionary feature of eukaryotic cells is the emergence of membrane-bound organelles. Compartmentalization allows each organelle to maintain a spatially, physically, and chemically distinct environment, which greatly bolsters individual organelle function. However, the activities of each organelle must be balanced and are interdependent for cellular homeostasis. Therefore, properly regulated interactions between organelles, either physically or functionally, remain critical for overall cellular health and behavior. In particular, neuronal homeostasis depends heavily on the proper regulation of organelle function and cross talk, and deficits in these functions are frequently associated with diseases. In this review, we examine the emerging role of organelle contacts in neurological diseases and discuss how the disruption of contacts contributes to disease pathogenesis. Understanding the molecular mechanisms underlying the formation and regulation of organelle contacts will broaden our knowledge of their role in health and disease, laying the groundwork for the development of new therapies targeting interorganelle cross talk and function.
Topics: Endoplasmic Reticulum; Homeostasis; Organelles
PubMed: 35561676
DOI: 10.1016/j.neuron.2022.04.020 -
Journal of Cellular and Molecular... Dec 2023The migrasome is a new organelle discovered by Professor Yu Li in 2015. When cells migrate, the membranous organelles that appear at the end of the retraction fibres are... (Review)
Review
The migrasome is a new organelle discovered by Professor Yu Li in 2015. When cells migrate, the membranous organelles that appear at the end of the retraction fibres are migrasomes. With the migration of cells, the retraction fibres which connect migrasomes and cells finally break. The migrasomes detach from the cell and are released into the extracellular space or directly absorbed by the recipient cell. The cytoplasmic contents are first transported to the migrasome and then released from the cell through the migrasome. This release mechanism, which depends on cell migration, is named 'migracytosis'. The main components of the migrasome are extracellular vesicles after they leave the cell, which are easy to remind people of the current hot topic of exosomes. Exosomes are extracellular vesicles wrapped by the lipid bimolecular layer. With extensive research, exosomes have solved many disease problems. This review summarizes the differences between migrasomes and exosomes in size, composition, property and function, extraction method and regulation mechanism for generation and release. At the same time, it also prospects for the current hotspot of migrasomes, hoping to provide literature support for further research on the generation and release mechanism of migrasomes and their clinical application in the future.
Topics: Humans; Exosomes; Organelles; Cell Movement; Extracellular Vesicles; Biological Transport
PubMed: 37665060
DOI: 10.1111/jcmm.17942 -
Cellular and Molecular Life Sciences :... Aug 2023Lipids in cell membranes and subcellular compartments play essential roles in numerous cellular processes, such as energy production, cell signaling and inflammation. A... (Review)
Review
Lipids in cell membranes and subcellular compartments play essential roles in numerous cellular processes, such as energy production, cell signaling and inflammation. A specific organelle lipidome is characterized by lipid synthesis and metabolism, intracellular trafficking, and lipid homeostasis in the organelle. Over the years, considerable effort has been directed to the identification of the lipid fingerprints of cellular organelles. However, these fingerprints are not fully characterized due to the large variety and structural complexity of lipids and the great variability in the abundance of different lipid species. The process becomes even more challenging when considering that the lipidome differs in health and disease contexts. This review summarizes the information available on the lipid composition of mammalian cell organelles, particularly the lipidome of the nucleus, mitochondrion, endoplasmic reticulum, Golgi apparatus, plasma membrane and organelles in the endocytic pathway. The lipid compositions of extracellular vesicles and lamellar bodies are also described. In addition, several examples of subcellular lipidome dynamics under physiological and pathological conditions are presented. Finally, challenges in mapping organelle lipidomes are discussed.
Topics: Animals; Lipids; Lipidomics; Lipid Metabolism; Organelles; Cell Nucleus; Mitochondria; Mammals
PubMed: 37530856
DOI: 10.1007/s00018-023-04889-3 -
Molecular Biology of the Cell Dec 2022In 1956, referring to the emerging application of electron microscopy to the study of eukaryotic cells, Keith R. Porter wrote, "For those of us who are fortunate to be...
In 1956, referring to the emerging application of electron microscopy to the study of eukaryotic cells, Keith R. Porter wrote, "For those of us who are fortunate to be part of this new development, these are days of great interest and opportunity." Those early days left us a rich legacy of knowledge on the internal organization of eukaryotic cells that provides a framework for current research on cell structure and function. In this vein, my long-time quest has been to understand how proteins and organelles travel through the cytoplasm to reach their respective destinations within the cell. This research has led us to elucidate various mechanisms of protein sorting and organelle transport and how defects in these mechanisms cause human disease.
Topics: Humans; Organelles; Microscopy, Electron; Biological Transport; Cytoplasm; Protein Transport
PubMed: 36399622
DOI: 10.1091/mbc.E22-08-0362