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Molecular Cell Apr 2022Organelles are continuously turned over as part of cellular homeostasis and adaptation. Most organelles, even including the nucleus, are degraded by lysosomes via...
Organelles are continuously turned over as part of cellular homeostasis and adaptation. Most organelles, even including the nucleus, are degraded by lysosomes via different pathways, such as macroautophagy, microautophagy, organelle-derived vesicle degradation, and crinophagy. In some specific cases-for example, in lens fiber cells-organelles are degraded by cytosolic phospholipases. To view this SnapShot, open or download the PDF.
Topics: Autophagy; Cytosol; Lens, Crystalline; Lysosomes; Organelles
PubMed: 35452619
DOI: 10.1016/j.molcel.2022.03.015 -
Plant Physiology Aug 2023Organelles function as hubs of cellular metabolism and elements of cellular architecture. In addition to 3 spatial dimensions that describe the morphology and... (Review)
Review
Organelles function as hubs of cellular metabolism and elements of cellular architecture. In addition to 3 spatial dimensions that describe the morphology and localization of each organelle, the time dimension describes complexity of the organelle life cycle, comprising formation, maturation, functioning, decay, and degradation. Thus, structurally identical organelles could be biochemically different. All organelles present in a biological system at a given moment of time constitute the organellome. The homeostasis of the organellome is maintained by complex feedback and feedforward interactions between cellular chemical reactions and by the energy demands. Synchronized changes of organelle structure, activity, and abundance in response to environmental cues generate the fourth dimension of plant polarity. Temporal variability of the organellome highlights the importance of organellomic parameters for understanding plant phenotypic plasticity and environmental resiliency. Organellomics involves experimental approaches for characterizing structural diversity and quantifying the abundance of organelles in individual cells, tissues, or organs. Expanding the arsenal of appropriate organellomics tools and determining parameters of the organellome complexity would complement existing -omics approaches in comprehending the phenomenon of plant polarity. To highlight the importance of the fourth dimension, this review provides examples of organellome plasticity during different developmental or environmental situations.
Topics: Organelles; Plants
PubMed: 37243543
DOI: 10.1093/plphys/kiad310 -
MBio Aug 2021Apicomplexan parasites, such as Toxoplasma gondii and Plasmodium falciparum, are the cause of many important human and animal diseases. While T. gondii tachyzoites... (Review)
Review
Apicomplexan parasites, such as Toxoplasma gondii and Plasmodium falciparum, are the cause of many important human and animal diseases. While T. gondii tachyzoites replicate through endodyogeny, during which two daughter cells are formed within the parental cell, P. falciparum replicates through schizogony, where up to 32 parasites are formed in a single infected red blood cell and even thousands of daughter cells during mosquito- or liver-stage development. These processes require a tightly orchestrated division and distribution over the daughter parasites of one-per-cell organelles such as the mitochondrion and apicoplast. Although proper organelle segregation is highly essential, the molecular mechanism and the key proteins involved remain largely unknown. In this review, we describe organelle dynamics during cell division in T. gondii and P. falciparum, summarize the current understanding of the molecular mechanisms underlying organelle fission in these parasites, and introduce candidate fission proteins.
Topics: Animals; Apicoplasts; Erythrocytes; Humans; Mitochondria; Parasites; Plasmodium falciparum; Protozoan Proteins; Toxoplasma
PubMed: 34425697
DOI: 10.1128/mBio.01409-21 -
Annual Review of Analytical Chemistry... Jun 2022Cellular organelles are highly specialized compartments with distinct functions. With the increasing resolution of detection methods, it is becoming clearer that same... (Review)
Review
Cellular organelles are highly specialized compartments with distinct functions. With the increasing resolution of detection methods, it is becoming clearer that same organelles may have different functions or properties not only within different cell populations of a tissue but also within the same cell. Dysfunction or altered function affects the organelle itself and may also lead to malignancies or undesirable cell death. To understand cellular function or dysfunction, it is therefore necessary to analyze cellular components at the single-organelle level. Here, we review the recent advances in analyzing cellular function at single-organelle resolution using high-parameter flow cytometry or multicolor confocal microscopy. We focus on the analysis of mitochondria, as they are organelles at the crossroads of various cellular signaling pathways and functions. However, most of the applied methods/technologies are transferable to any other organelle, such as the endoplasmic reticulum, lysosomes, or peroxisomes.
Topics: Endoplasmic Reticulum; Lysosomes; Microscopy, Confocal; Mitochondria; Peroxisomes
PubMed: 35303775
DOI: 10.1146/annurev-anchem-061020-111722 -
Current Opinion in Cell Biology Apr 2022The majority of cellular proteins are targeted to organelles. Cytosolic ribosomes produce these proteins as precursors with cleavable or non-cleavable targeting... (Review)
Review
The majority of cellular proteins are targeted to organelles. Cytosolic ribosomes produce these proteins as precursors with cleavable or non-cleavable targeting sequences that direct them to receptor proteins on the organelle surface. Multiple targeting factors ensure cellular sorting of the precursor proteins. In co-translational protein import, the ribosome-nascent chain complex is transported to the organellar protein translocase to couple protein synthesis and protein import. In post-translational mode, targeting factors like molecular chaperones guide the precursor proteins from ribosomes to the cell organelle. Defects in protein targeting and import cause mistargeting of proteins to different cellular compartments and challenge the balance of cellular proteostasis. Specific dislocases and degradation machineries remove such mislocalized proteins from the membrane to allow retargeting or their proteasomal turnover. In this review, we discuss targeting and quality control factors that ensure fidelity of protein targeting to mitochondria.
Topics: Mitochondria; Molecular Chaperones; Organelles; Protein Precursors; Protein Transport; Ribosomes
PubMed: 35306313
DOI: 10.1016/j.ceb.2022.02.005 -
ACS Applied Materials & Interfaces May 2021Subcellular organelles are the cornerstones of cells, and destroying them will cause cell dysfunction and even death. Therefore, realizing precise organelle targeting of... (Review)
Review
Subcellular organelles are the cornerstones of cells, and destroying them will cause cell dysfunction and even death. Therefore, realizing precise organelle targeting of photosensitizers (PSs) can help reduce PS dosage, minimize side effects, avoid drug resistance, and enhance therapeutic efficacy in photodynamic therapy (PDT). Organelle-targeted PSs provide a new paradigm for the construction of the next generation of PSs and may provide implementable strategies for future precision medicine. In this Review, the recent targeting strategies of different organelles and the corresponding design principles of molecular and nanostructured PSs are summarized and discussed. The current challenges and opportunities in organelle-targeted PDT are also presented.
Topics: Drug Delivery Systems; Humans; Organelles; Photochemotherapy; Photosensitizing Agents
PubMed: 33900741
DOI: 10.1021/acsami.1c02019 -
Cells Sep 2022The Golgi apparatus (GA) is essential for intracellular sorting, trafficking and the targeting of proteins to specific cellular compartments. Anatomically, the GA... (Review)
Review
The Golgi apparatus (GA) is essential for intracellular sorting, trafficking and the targeting of proteins to specific cellular compartments. Anatomically, the GA spreads all over the cell but is also particularly enriched close to the base of the primary cilium. This peculiar organelle protrudes at the surface of almost all cells and fulfills many cellular functions, in particular during development, when a dysfunction of the primary cilium can lead to disorders called ciliopathies. While ciliopathies caused by loss of ciliated proteins have been extensively documented, several studies suggest that alterations of GA and GA-associated proteins can also affect ciliogenesis. Here, we aim to discuss how the loss-of-function of genes coding these proteins induces ciliary defects and results in ciliopathies.
Topics: Cell Movement; Cilia; Ciliopathies; Golgi Apparatus; Humans; Organelles
PubMed: 36139347
DOI: 10.3390/cells11182773 -
Current Opinion in Cell Biology Aug 2019Cytoskeletal motors of the dynein, kinesin and myosin superfamilies maintain and adapt subcellular organelle organization to meet functional demands and support the... (Review)
Review
Cytoskeletal motors of the dynein, kinesin and myosin superfamilies maintain and adapt subcellular organelle organization to meet functional demands and support the vesicular transport of material between organelles. These motors require the capacity to specifically recognize the vesicle/organelle to be transported and are capable of selective recognition of multiple cargo. Recent studies have begun to uncover the molecular basis for motor recruitment and have highlighted the role of organelle-associated 'cargo-adaptor' proteins in cellular transport. These adaptors possess sequences and/or structural features that enable both motor recruitment and activation from regulated, inactive, states to enable motility on the cytoskeleton. Motor-cargo adaptor interactions define a key organelle-cytoskeleton interface, acting as crucial regulatory hubs to enable the cell to finely control membrane trafficking and organelle dynamics. Understanding the molecular basis of these interactions may offer new opportunities to control and manipulate cytoskeletal and organelle dynamics for the development of new research tools and potentially therapeutics.
Topics: Cytoskeleton; Humans; Organelles; Protein Transport
PubMed: 30952037
DOI: 10.1016/j.ceb.2019.02.010 -
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 -
Biochemical Society Transactions Oct 2022Advances in public health have nearly doubled life expectancy over the last century, but this demographic shift has also changed the landscape of human illness. Today,... (Review)
Review
Advances in public health have nearly doubled life expectancy over the last century, but this demographic shift has also changed the landscape of human illness. Today, chronic and age-dependent diseases dominate the leading causes of morbidity and mortality worldwide. Targeting the underlying molecular, genetic and cell biological drivers of the aging process itself appears to be an increasingly viable strategy for developing therapeutics against these diseases of aging. Towards this end, one of the most exciting developments in cell biology over the last decade is the explosion of research into organelle contact sites and related mechanisms of inter-organelle communication. Identification of the molecular mediators of inter-organelle tethering and signaling is now allowing the field to investigate the consequences of aberrant organelle interactions, which frequently seem to correlate with age-onset pathophysiology. This review introduces the major cellular roles for inter-organelle interactions, including the regulation of organelle morphology, the transfer of ions, lipids and other metabolites, and the formation of hubs for nutrient and stress signaling. We explore how these interactions are disrupted in aging and present findings that modulation of inter-organelle communication is a promising avenue for promoting longevity. Through this review, we propose that the maintenance of inter-organelle interactions is a pillar of healthy aging. Learning how to target the cellular mechanisms for sensing and controlling inter-organelle communication is a key next hurdle for geroscience.
Topics: Humans; Aging; Longevity; Mitochondrial Membranes; Organelles; Cell Communication
PubMed: 36305642
DOI: 10.1042/BST20220519