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Developmental Cell Apr 2017The selective clearance of organelles by autophagy is critical for the regulation of cellular homeostasis in organisms from yeast to humans. Removal of damaged... (Review)
Review
The selective clearance of organelles by autophagy is critical for the regulation of cellular homeostasis in organisms from yeast to humans. Removal of damaged organelles clears the cell of potentially toxic byproducts and enables reuse of organelle components for bioenergetics. Thus, defects in organelle clearance may be detrimental to the health of the cells, contributing to cancer, neurodegeneration, and inflammatory diseases. Organelle-specific autophagy can clear mitochondria, peroxisomes, lysosomes, ER, chloroplasts, and the nucleus. Here, we review our understanding of the mechanisms that regulate the clearance of organelles by autophagy and highlight gaps in our knowledge of these processes.
Topics: Animals; Autophagy; Humans; Mitophagy; Models, Biological; Organelles
PubMed: 28399394
DOI: 10.1016/j.devcel.2017.02.016 -
Current Opinion in Cell Biology Feb 2014A number of bacterial species rely on compartmentalization to gain specific functionalities that will provide them with a selective advantage. Here, we will highlight... (Review)
Review
A number of bacterial species rely on compartmentalization to gain specific functionalities that will provide them with a selective advantage. Here, we will highlight several of these modes of bacterial compartmentalization with an eye toward describing the mechanisms of their formation and their evolutionary origins. Spore formation in Bacillus subtilis, outer membrane biogenesis in Gram-negative bacteria and protein diffusion barriers of Caulobacter crescentus will be used to demonstrate the physical, chemical, and compositional remodeling events that lead to compartmentalization. In addition, magnetosomes and carboxysomes will serve as models to examine the interplay between cytoskeletal systems and the subcellular positioning of organelles.
Topics: Bacteria; Bacterial Proteins; Cell Membrane; Diffusion; Organelles; Protein Transport
PubMed: 24440431
DOI: 10.1016/j.ceb.2013.12.007 -
Kidney International Jun 2019Organelle damage can cause various kidney diseases. In particular, organelle stress such as decreased proteostatic activity in the endoplasmic reticulum (ER) and altered... (Review)
Review
Organelle damage can cause various kidney diseases. In particular, organelle stress such as decreased proteostatic activity in the endoplasmic reticulum (ER) and altered energy metabolism in mitochondria contribute to glomerular and tubulointerstitial damage, resulting in the progression and development of kidney diseases. The ER regulates protein quality control via the unfolded protein response (UPR) pathway. Pathogenic ER stress leads to dysregulation of this pathway, and a maladaptive UPR is highly deleterious to renal cell function, and thereby has been implicated in the pathophysiology of various kidney diseases. The UPR pathway in the ER also regulates mitochondrial metabolic status, indicating the pathophysiological significance of organelle crosstalk between the ER and mitochondria via the UPR pathway. In recent years, it has become obvious that communication among organelles also is conducted through direct interactions at membrane contact sites (MCSs). Organelles exchange materials including lipids, ions, and proteins at the MCS. Accordingly, alterations to these networks, such as impaired ER-mitochondria MCSs, have been linked to several diseases such as neurodegeneration and diabetes. In this review, we describe the roles of organelles in kidney diseases and the mechanisms underlying organelle communication at the MCS, and especially at the mitochondria-associated ER membrane. Potential treatment options that are focused on organelle crosstalk are discussed, in addition to the relationship between this phenomenon and various diseases, especially kidney diseases.
Topics: Animals; Disease Progression; Endoplasmic Reticulum; Endoplasmic Reticulum Stress; Humans; Intracellular Membranes; Kidney; Kidney Diseases; Lysosomes; Mitochondria; Peroxisomes; Unfolded Protein Response
PubMed: 30878214
DOI: 10.1016/j.kint.2018.11.035 -
Annual Review of Cell and Developmental... Oct 2020As cells grow, the size and number of their internal organelles increase in order to keep up with increased metabolic requirements. Abnormal size of organelles is a... (Review)
Review
As cells grow, the size and number of their internal organelles increase in order to keep up with increased metabolic requirements. Abnormal size of organelles is a hallmark of cancer and an important aspect of diagnosis in cytopathology. Most organelles vary in either size or number, or both, as a function of cell size, but the mechanisms that create this variation remain unclear. In some cases, organelle size appears to scale with cell size through processes of relative growth, but in others the size may be set by either active measurement systems or genetic programs that instruct organelle biosynthetic activities to create organelles of a size appropriate to a given cell type.
Topics: Animals; Humans; Models, Biological; Organelles; Subcellular Fractions
PubMed: 32603615
DOI: 10.1146/annurev-cellbio-020520-113246 -
The Plant Journal : For Cell and... Sep 2007Genome sequencing has resulted in the identification of a large number of uncharacterized genes with unknown functions. It is widely recognized that determination of the...
Genome sequencing has resulted in the identification of a large number of uncharacterized genes with unknown functions. It is widely recognized that determination of the intracellular localization of the encoded proteins may aid in identifying their functions. To facilitate these localization experiments, we have generated a series of fluorescent organelle markers based on well-established targeting sequences that can be used for co-localization studies. In particular, this organelle marker set contains indicators for the endoplasmic reticulum, the Golgi apparatus, the tonoplast, peroxisomes, mitochondria, plastids and the plasma membrane. All markers were generated with four different fluorescent proteins (FP) (green, cyan, yellow or red FPs) in two different binary plasmids for kanamycin or glufosinate selection, respectively, to allow for flexible combinations. The labeled organelles displayed characteristic morphologies consistent with previous descriptions that could be used for their positive identification. Determination of the intracellular distribution of three previously uncharacterized proteins demonstrated the usefulness of the markers in testing predicted subcellular localizations. This organelle marker set should be a valuable resource for the plant community for such co-localization studies. In addition, the Arabidopsis organelle marker lines can also be employed in plant cell biology teaching labs to demonstrate the distribution and dynamics of these organelles.
Topics: Arabidopsis; Arabidopsis Proteins; Biomarkers; Luminescent Proteins; Organelles; Plasmids; Protein Transport
PubMed: 17666025
DOI: 10.1111/j.1365-313X.2007.03212.x -
International Journal of Molecular... Dec 2022Interorganelle membrane contact sites (MCS) are areas of close vicinity between the membranes of two organelles that are maintained by protein tethers. Recently, a... (Review)
Review
Interorganelle membrane contact sites (MCS) are areas of close vicinity between the membranes of two organelles that are maintained by protein tethers. Recently, a significant research effort has been made to study MCS, as they are implicated in a wide range of biological functions, such as organelle biogenesis and division, apoptosis, autophagy, and ion and phospholipid homeostasis. Their composition, characteristics, and dynamics can be studied by different techniques, but in recent years super-resolution fluorescence microscopy (SRFM) has emerged as a powerful tool for studying MCS. In this review, we first explore the main characteristics and biological functions of MCS and summarize the different approaches for studying them. Then, we center on SRFM techniques that have been used to study MCS. For each of the approaches, we summarize their working principle, discuss their advantages and limitations, and explore the main discoveries they have uncovered in the field of MCS.
Topics: Microscopy, Fluorescence; Organelles; Mitochondrial Membranes
PubMed: 36499680
DOI: 10.3390/ijms232315354 -
The FEBS Journal Nov 2022The major criterion that distinguishes eukaryotes from prokaryotes is the presence of organelles in the former. Organelles provide a compartment in which biochemical...
The major criterion that distinguishes eukaryotes from prokaryotes is the presence of organelles in the former. Organelles provide a compartment in which biochemical processes are corralled within bespoke biophysical conditions and act as storage depots, powerhouses, waste storage/recycling units and innate immune signalling hubs. A key challenge faced by organelles is to define, and then retain, their identity; this is mediated by complex proteostasis mechanisms including the import of an organelle-specific proteome, the exclusion of non-organellar proteins and the removal of misfolded proteins via dedicated quality control mechanisms. This Special Issue on Organelle Homeostasis provides an engaging, eclectic, yet integrative, perspective on organelle homeostasis in a range of organelles including those from the secretory and endocytic pathways, mitochondria, the autophagy-lysosomal pathway and the nucleus and its sub-compartments. Some lesser-known organelles including migrasomes (organelles that are released by migrating cells) and GOMED (a Golgi-specific form of autophagy) are also introduced. In the spirit of the principles of organelle biology, we hope you find the reviews in this Issue both encapsulating and captivating, and we thank the authors for their excellent contributions.
Topics: Endoplasmic Reticulum; Organelles; Golgi Apparatus; Lysosomes; Mitochondria; Homeostasis
PubMed: 36377590
DOI: 10.1111/febs.16667 -
Topics in Current Chemistry (Cham) Dec 2023While bioorthogonal reactions are routinely employed in living cells and organisms, their application within individual organelles remains limited. In this review, we... (Review)
Review
While bioorthogonal reactions are routinely employed in living cells and organisms, their application within individual organelles remains limited. In this review, we highlight diverse examples of bioorthogonal reactions used to investigate the roles of biomolecules and biological processes as well as advanced imaging techniques within cellular organelles. These innovations hold great promise for therapeutic interventions in personalized medicine and precision therapies. We also address existing challenges related to the selectivity and trafficking of subcellular dynamics. Organelle-targeted bioorthogonal reactions have the potential to significantly advance our understanding of cellular organization and function, provide new pathways for basic research and clinical applications, and shape the direction of cell biology and medical research.
Topics: Organelles; Cell Biology
PubMed: 38103067
DOI: 10.1007/s41061-023-00446-5 -
RNA Biology 2014I am honored to have been asked to contribute to this memorial issue, although I cannot claim to have known Carl Woese well. Carl's insights and the discoveries that his... (Review)
Review
I am honored to have been asked to contribute to this memorial issue, although I cannot claim to have known Carl Woese well. Carl's insights and the discoveries that his research group made over the years certainly stimulated my own research program, and at several points early on, interactions with him were pivotal in my career. Here I comment on these personal dealings with Carl and emphasize his influence in two areas of long-standing interest in my lab: organelle evolution and rRNA evolution.
Topics: Evolution, Molecular; Organelles; Phylogeny; Plants; RNA, Plant; RNA, Ribosomal
PubMed: 24572720
DOI: 10.4161/rna.27799 -
International Journal of Molecular... May 2017Over the past decades, peroxisomes have emerged as key regulators in overall cellular lipid and reactive oxygen species metabolism. In mammals, these organelles have... (Review)
Review
Over the past decades, peroxisomes have emerged as key regulators in overall cellular lipid and reactive oxygen species metabolism. In mammals, these organelles have also been recognized as important hubs in redox-, lipid-, inflammatory-, and innate immune-signaling networks. To exert these activities, peroxisomes must interact both functionally and physically with other cell organelles. This review provides a comprehensive look of what is currently known about the interconnectivity between peroxisomes and mitochondria within mammalian cells. We first outline how peroxisomal and mitochondrial abundance are controlled by common sets of - and -acting factors. Next, we discuss how peroxisomes and mitochondria may communicate with each other at the molecular level. In addition, we reflect on how these organelles cooperate in various metabolic and signaling pathways. Finally, we address why peroxisomes and mitochondria have to maintain a healthy relationship and why defects in one organelle may cause dysfunction in the other. Gaining a better insight into these issues is pivotal to understanding how these organelles function in their environment, both in health and disease.
Topics: Animals; Cellular Senescence; Fatty Acids; Humans; Metabolic Networks and Pathways; Mitochondria; Oxidation-Reduction; Peroxisomes; Reactive Oxygen Species; Signal Transduction
PubMed: 28538669
DOI: 10.3390/ijms18061126