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Results and Problems in Cell... 2019The Golgi apparatus is a central intracellular membrane-bound organelle with key functions in trafficking, processing, and sorting of newly synthesized membrane and... (Review)
Review
The Golgi apparatus is a central intracellular membrane-bound organelle with key functions in trafficking, processing, and sorting of newly synthesized membrane and secretory proteins and lipids. To best perform these functions, Golgi membranes form a unique stacked structure. The Golgi structure is dynamic but tightly regulated; it undergoes rapid disassembly and reassembly during the cell cycle of mammalian cells and is disrupted under certain stress and pathological conditions. In the past decade, significant amount of effort has been made to reveal the molecular mechanisms that regulate the Golgi membrane architecture and function. Here we review the major discoveries in the mechanisms of Golgi structure formation, regulation, and alteration in relation to its functions in physiological and pathological conditions to further our understanding of Golgi structure and function in health and diseases.
Topics: Animals; Biological Transport; Cell Cycle; Disease; Golgi Apparatus; Health; Humans; Intracellular Membranes; Stress, Physiological
PubMed: 31435807
DOI: 10.1007/978-3-030-23173-6_19 -
Molecular Biology of the Cell Jul 1998
Topics: Animals; Biological Transport; Brefeldin A; COS Cells; Endoplasmic Reticulum; Golgi Apparatus; Green Fluorescent Proteins; Intracellular Membranes; Light; Luminescent Proteins; Membrane Glycoproteins; Microscopy, Video; Vesicular stomatitis Indiana virus; Video Recording; Viral Envelope Proteins
PubMed: 9658158
DOI: 10.1091/mbc.9.7.1617 -
Science (New York, N.Y.) Sep 2020Coronavirus genome replication is associated with virus-induced cytosolic double-membrane vesicles, which may provide a tailored microenvironment for viral RNA synthesis...
Coronavirus genome replication is associated with virus-induced cytosolic double-membrane vesicles, which may provide a tailored microenvironment for viral RNA synthesis in the infected cell. However, it is unclear how newly synthesized genomes and messenger RNAs can travel from these sealed replication compartments to the cytosol to ensure their translation and the assembly of progeny virions. In this study, we used cellular cryo-electron microscopy to visualize a molecular pore complex that spans both membranes of the double-membrane vesicle and would allow export of RNA to the cytosol. A hexameric assembly of a large viral transmembrane protein was found to form the core of the crown-shaped complex. This coronavirus-specific structure likely plays a key role in coronavirus replication and thus constitutes a potential drug target.
Topics: Animals; Cryoelectron Microscopy; Cytoplasmic Vesicles; Electron Microscope Tomography; Intracellular Membranes; Mice; Murine hepatitis virus; RNA, Viral; Viral Nonstructural Proteins; Virus Replication
PubMed: 32763915
DOI: 10.1126/science.abd3629 -
Cellular and Molecular Life Sciences :... Oct 2018Viruses are obligate intracellular pathogens that are dependent on cellular machineries for their replication. Recent technological breakthroughs have facilitated... (Review)
Review
Viruses are obligate intracellular pathogens that are dependent on cellular machineries for their replication. Recent technological breakthroughs have facilitated reliable identification of host factors required for viral infections and better characterization of the virus-host interplay. While these studies have revealed cellular machineries that are uniquely required by individual viruses, accumulating data also indicate the presence of broadly required mechanisms. Among these overlapping cellular functions are components of intracellular membrane trafficking pathways. Here, we review recent discoveries focused on how viruses exploit intracellular membrane trafficking pathways to promote various stages of their life cycle, with an emphasis on cellular factors that are usurped by a broad range of viruses. We describe broadly required components of the endocytic and secretory pathways, the Endosomal Sorting Complexes Required for Transport pathway, and the autophagy pathway. Identification of such overlapping host functions offers new opportunities to develop broad-spectrum host-targeted antiviral strategies.
Topics: Autophagy; Clathrin; Endosomal Sorting Complexes Required for Transport; Host-Pathogen Interactions; Humans; Intracellular Membranes; Lysosomes; Secretory Pathway; Virus Internalization; Viruses
PubMed: 30043139
DOI: 10.1007/s00018-018-2882-0 -
The Journal of Membrane Biology Jun 2021G protein-coupled receptors (GPCRs) are integral membrane proteins that transduce a wide array of inputs including light, ions, hormones, and neurotransmitters into... (Review)
Review
G protein-coupled receptors (GPCRs) are integral membrane proteins that transduce a wide array of inputs including light, ions, hormones, and neurotransmitters into intracellular signaling responses which underlie complex processes ranging from vision to learning and memory. Although traditionally thought to signal primarily from the cell surface, GPCRs are increasingly being recognized as capable of signaling from intracellular membrane compartments, including endosomes, the Golgi apparatus, and nuclear membranes. Remarkably, GPCR signaling from these membranes produces functional effects that are distinct from signaling from the plasma membrane, even though often the same G protein effectors and second messengers are activated. In this review, we will discuss the emerging idea of a "spatial bias" in signaling. We will present the evidence for GPCR signaling through G protein effectors from intracellular membranes, and the ways in which this signaling differs from canonical plasma membrane signaling with important implications for physiology and pharmacology. We also highlight the potential mechanisms underlying spatial bias of GPCR signaling, including how intracellular membranes and their associated lipids and proteins affect GPCR activity and signaling.
Topics: Endosomes; Intracellular Membranes; Protein Transport; Receptors, G-Protein-Coupled; Signal Transduction
PubMed: 33231722
DOI: 10.1007/s00232-020-00158-7 -
Current Opinion in Cell Biology Aug 2021The de novo generation of double-membrane autophagosomes is the hallmark of autophagy. The initial membranous precursor cisterna, the phagophore, is very likely... (Review)
Review
The de novo generation of double-membrane autophagosomes is the hallmark of autophagy. The initial membranous precursor cisterna, the phagophore, is very likely generated by the fusion of vesicles and acts as a membrane seed for the subsequent expansion into an autophagosome. This latter step requires a massive convoy of lipids into the phagophore. In this review, we present recent advances in our understanding of the intracellular membrane sources and lipid delivery mechanisms, which principally rely on vesicular transport and membrane contact sites that contribute to autophagosome biogenesis. In this context, we discuss lipid biosynthesis and lipid remodeling events that play a crucial role in both phagophore nucleation and expansion.
Topics: Autophagosomes; Autophagy; Intracellular Membranes
PubMed: 33930785
DOI: 10.1016/j.ceb.2021.02.001 -
Current Opinion in Cell Biology Aug 2018From unicellular protists to the largest megafauna and flora, all eukaryotes depend upon the organelles and processes of the intracellular membrane trafficking system.... (Review)
Review
From unicellular protists to the largest megafauna and flora, all eukaryotes depend upon the organelles and processes of the intracellular membrane trafficking system. Well-defined machinery selectively packages and delivers material between endomembrane organelles and imports and exports material from the cell surface. This process underlies intracellular compartmentalization and facilitates myriad processes that define eukaryotic biology. Membrane trafficking is a landmark in the origins of the eukaryotic cell and recent work has begun to unravel how the revolution in cellular structure occurred.
Topics: Animals; Biological Transport; Cell Membrane; Eukaryota; Eukaryotic Cells; Evolution, Molecular; Intracellular Membranes; Organelles; Trypanosomatina
PubMed: 29929066
DOI: 10.1016/j.ceb.2018.06.001 -
Viruses Jun 2021Flavivirus consists of a large number of arthropod-borne viruses, many of which cause life-threatening diseases in humans. A characteristic feature of flavivirus... (Review)
Review
Flavivirus consists of a large number of arthropod-borne viruses, many of which cause life-threatening diseases in humans. A characteristic feature of flavivirus infection is to induce the rearrangement of intracellular membrane structure in the cytoplasm. This unique membranous structure called replication organelle is considered as a microenvironment that provides factors required for the activity of the flaviviral replication complex. The replication organelle serves as a place to coordinate viral RNA amplification, protein translation, and virion assembly and also to protect the viral replication complex from the cellular immune defense system. In this review, we summarize the current understanding of how the formation and function of membrane-associated flaviviral replication organelle are regulated by cellular factors.
Topics: Endoplasmic Reticulum; Flavivirus; Flavivirus Infections; Host-Pathogen Interactions; Humans; Intracellular Membranes; Protein Biosynthesis; RNA, Viral; Viral Nonstructural Proteins; Virus Replication
PubMed: 34205058
DOI: 10.3390/v13061060 -
Biomolecules Dec 2020, and are pathogenic bacteria capable of causing disease in humans by growing extracellularly in lymph nodes and during systemic infections. While the capacity of... (Review)
Review
, and are pathogenic bacteria capable of causing disease in humans by growing extracellularly in lymph nodes and during systemic infections. While the capacity of these bacteria to invade, replicate, and survive within host cells has been known for long, it is only in recent years that their intracellular stages have been explored in more detail. Current evidence suggests that pathogenic are capable of activating autophagy in both phagocytic and epithelial cells, subverting autophagosome formation to create a niche supporting bacterial intracellular replication. In this review, we discuss recent results opening novel perspectives to the understanding of intimate host-pathogens interactions taking place during enteric yersiniosis and plague.
Topics: Animals; Autophagy; Biological Transport; Host-Pathogen Interactions; Humans; Intracellular Membranes; Yersinia
PubMed: 33291818
DOI: 10.3390/biom10121637 -
International Journal of Molecular... Mar 2023The main component of blood and lymphatic vessels is the endothelium covering their luminal surface. It plays a significant role in many cardiovascular diseases.... (Review)
Review
The main component of blood and lymphatic vessels is the endothelium covering their luminal surface. It plays a significant role in many cardiovascular diseases. Tremendous progress has been made in deciphering of molecular mechanisms involved into intracellular transport. However, molecular machines are mostly characterized in vitro. It is important to adapt this knowledge to the situation existing in tissues and organs. Moreover, contradictions have accumulated within the field related to the function of endothelial cells (ECs) and their trans-endothelial pathways. This has induced necessity for the re-evaluation of several mechanisms related to the function of vascular ECs and intracellular transport and transcytosis there. Here, we analyze available data related to intracellular transport within ECs and re-examine several hypotheses about the role of different mechanisms in transcytosis across ECs. We propose a new classification of vascular endothelium and hypotheses related to the functional role of caveolae and mechanisms of lipid transport through ECs.
Topics: Endothelial Cells; Biological Transport; Transcytosis; Caveolae; Intracellular Membranes; Endothelium, Vascular
PubMed: 36982865
DOI: 10.3390/ijms24065791