scholarly journals Tumor Protein D54 defines a new class of intracellular transport vesicle

2018 ◽  
Author(s):  
Gabrielle Larocque ◽  
Penelope J. La-Borde ◽  
Nicholas I. Clarke ◽  
Nicholas J. Carter ◽  
Stephen J. Royle
Keyword(s):  
Membrane Trafficking ◽  
Intracellular Transport ◽  
Super Resolution ◽  
Molecular Heterogeneity ◽  
Rab Gtpases ◽  
New Class ◽  
Transport Vesicle ◽  
Membrane Compartment ◽  
Generic Class ◽  
Resolution Imaging

Transport of proteins and lipids from one membrane compartment to another is via intracellular vesicles. We investigated the function of Tumor Protein D54 (TPD54/TPD52L2), and found that TPD54 was involved in multiple membrane trafficking pathways: anterograde traffic, recycling and Golgi integrity. To understand how TPD54 controls these diverse functions, we used an inducible method to reroute TPD54 to mitochondria. Surprisingly, this manipulation resulted in the capture of many small vesicles (30 nm diameter) at the mitochondrial surface. Super-resolution imaging confirmed the presence of similarly sized TPD54-positive structures under normal conditions. It appears that TPD54 defines a new class of transport vesicle, which we term intracellular nanovesicles (INVs). INVs meet three criteria for functionality. They contain specific cargo, they have certain R-SNAREs for fusion, and they are endowed with a variety of Rab GTPases (16 out of 43 tested). The molecular heterogeneity of INVs and the diverse functions of TPD54 suggest that INVs have various membrane origins and a number of destinations. We propose that INVs are a generic class of transport vesicle which transfer cargo between these varied locations.

scholarly journals Tumor protein D54 defines a new class of intracellular transport vesicles

2019 ◽  
Vol 219 (1) ◽  
Author(s):  
Gabrielle Larocque ◽  
Penelope J. La-Borde ◽  
Nicholas I. Clarke ◽  
Nicholas J. Carter ◽  
Stephen J. Royle
Keyword(s):  
Membrane Trafficking ◽  
Intracellular Transport ◽  
Super Resolution ◽  
Molecular Heterogeneity ◽  
Rab Gtpases ◽  
New Class ◽  
Transport Vesicles ◽  
Transport Vesicle ◽  
Membrane Compartment ◽  
Generic Class

Transport of proteins and lipids from one membrane compartment to another is via intracellular vesicles. We investigated the function of tumor protein D54 (TPD54/TPD52L2) and found that TPD54 was involved in multiple membrane trafficking pathways: anterograde traffic, recycling, and Golgi integrity. To understand how TPD54 controls these diverse functions, we used an inducible method to reroute TPD54 to mitochondria. Surprisingly, this manipulation resulted in the capture of many small vesicles (30 nm diameter) at the mitochondrial surface. Super-resolution imaging confirmed the presence of similarly sized TPD54-positive structures under normal conditions. It appears that TPD54 defines a new class of transport vesicle, which we term intracellular nanovesicles (INVs). INVs meet three criteria for functionality. They contain specific cargo, they have certain R-SNAREs for fusion, and they are endowed with a variety of Rab GTPases (16 out of 43 tested). The molecular heterogeneity of INVs and the diverse functions of TPD54 suggest that INVs have various membrane origins and a number of destinations. We propose that INVs are a generic class of transport vesicle that transfer cargo between these varied locations.

scholarly journals Rab5b-Associated Arf1 GTPase Regulates Export of N-Myristoylated Adenylate Kinase 2 From the Endoplasmic Reticulum in Plasmodium falciparum

2021 ◽  
Vol 10 ◽  
Author(s):  
Izumi Taku ◽  
Tomohiro Hirai ◽  
Takashi Makiuchi ◽  
Naoaki Shinzawa ◽  
Shiroh Iwanaga ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasmodium Falciparum ◽  
Membrane Trafficking ◽  
Adenylate Kinase ◽  
Parasitophorous Vacuole ◽  
Super Resolution ◽  
Immunofluorescence Assay ◽  
Rab Gtpases ◽  
Parasitophorous Vacuole Membrane ◽  
Vacuole Membrane

Plasmodium falciparum extensively remodels human erythrocytes by exporting hundreds of parasite proteins. This remodeling is closely linked to the Plasmodium virulence-related functions and immune evasion. The N-terminal export signal named PEXEL (Plasmodium export element) was identified to be important for the export of proteins beyond the PVM, however, the issue of how these PEXEL-positive proteins are transported and regulated by Rab GTPases from the endoplasmic reticulum (ER) to the cell surface has remained poorly understood. Previously, we identified new aspects of the trafficking of N-myristoylated adenylate kinase 2 (PfAK2), which lacks the PEXEL motif and is regulated by the PfRab5b GTPase. Overexpression of PfRab5b suppressed the transport of PfAK2 to the parasitophorous vacuole membrane and PfAK2 was accumulated in the punctate compartment within the parasite. Here, we report the identification of PfRab5b associated proteins and dissect the pathway regulated by PfRab5b. We isolated two membrane trafficking GTPases PfArf1 and PfRab1b by coimmunoprecipitation with PfRab5b and via mass analysis. PfArf1 and PfRab1b are both colocalized with PfRab5b adjacent to the ER in the early erythrocytic stage. A super-resolution microgram of the indirect immunofluorescence assay using PfArf1 or PfRab1b- expressing parasites revealed that PfArf1 and PfRab1b are localized to different ER subdomains. We used a genetic approach to expresses an active or inactive mutant of PfArf1 that specifically inhibited the trafficking of PfAK2 to the parasitophorous vacuole membrane. While expression of PfRab1b mutants did not affect in the PfAK2 transport. In contrast, the export of the PEXEL-positive protein Rifin was decreased by the expression of the inactive mutant of PfRab1b or PfArf1. These data indicate that the transport of PfAK2 and Rifin were recognized at the different ER subdomain by the two independent GTPases: PfAK2 is sorted by PfArf1 into the pathway for the PV, and the export of Rifin might be sequentially regulated by PfArf1 and PfRab1b.

scholarly journals Visualization and Manipulation of Actin Cytoskeleton with Small-Molecular Probes

2020 ◽  
Author(s):  
Takeru Takagi ◽  
Tasuku Ueno ◽  
Keisuke Ikawa ◽  
Daisuke Asanuma ◽  
Yusuke Nomura ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Green Light ◽  
Dynamic Network ◽  
Super Resolution ◽  
Molecular Probes ◽  
Actin Binding ◽  
Mechanical Forces ◽  
Cellular Functions ◽  
New Class ◽  
Resolution Imaging

Actin is a ubiquitous cytoskeletal protein, forming a dynamic network that generates mechanical forces in the cell. Here, in order to dissect the complex mechanisms of actin-related cellular functions, we introduce two powerful tools based on a new class of actin-binding small molecule: one enables visualization of the actin cytoskeleton, including super-resolution imaging, and the other enables highly specific green-light-controlled fragmentation of actin filaments, affording unprecedented control of the actin cytoskeleton and its force network in living cells.

scholarly journals Visualization and Manipulation of Actin Cytoskeleton with Small-Molecular Probes

2020 ◽  
Author(s):  
Takeru Takagi ◽  
Tasuku Ueno ◽  
Keisuke Ikawa ◽  
Daisuke Asanuma ◽  
Yusuke Nomura ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Green Light ◽  
Dynamic Network ◽  
Super Resolution ◽  
Molecular Probes ◽  
Actin Binding ◽  
Mechanical Forces ◽  
Cellular Functions ◽  
New Class ◽  
Resolution Imaging

Actin is a ubiquitous cytoskeletal protein, forming a dynamic network that generates mechanical forces in the cell. Here, in order to dissect the complex mechanisms of actin-related cellular functions, we introduce two powerful tools based on a new class of actin-binding small molecule: one enables visualization of the actin cytoskeleton, including super-resolution imaging, and the other enables highly specific green-light-controlled fragmentation of actin filaments, affording unprecedented control of the actin cytoskeleton and its force network in living cells.

scholarly journals Rab GTPases: Switching to Human Diseases

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 909 ◽  
Author(s):  
Noemi Antonella Guadagno ◽  
Cinzia Progida
Keyword(s):  
Membrane Trafficking ◽  
Intracellular Transport ◽  
Small Gtpases ◽  
Regulatory Proteins ◽  
Human Diseases ◽  
Rab Proteins ◽  
Rab Gtpases ◽  
Intracellular Membrane ◽  
And Migration ◽  
And Control

Rab proteins compose the largest family of small GTPases and control the different steps of intracellular membrane traffic. More recently, they have been shown to also regulate cell signaling, division, survival, and migration. The regulation of these processes generally occurs through recruitment of effectors and regulatory proteins, which control the association of Rab proteins to membranes and their activation state. Alterations in Rab proteins and their effectors are associated with multiple human diseases, including neurodegeneration, cancer, and infections. This review provides an overview of how the dysregulation of Rab-mediated functions and membrane trafficking contributes to these disorders. Understanding the altered dynamics of Rabs and intracellular transport defects might thus shed new light on potential therapeutic strategies.

scholarly journals Super-Resolution Imaging by Dielectric Superlenses: TiO2 Metamaterial Superlens versus BaTiO3 Superlens

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 222
Author(s):  
Rakesh Dhama ◽  
Bing Yan ◽  
Cristiano Palego ◽  
Zengbo Wang
Keyword(s):  
Super Resolution ◽  
Field Of View ◽  
Nano Particles ◽  
Imaging Systems ◽  
Label Free ◽  
Theoretical Simulation ◽  
New Class ◽  
Physical Shape ◽  
Resolution Imaging ◽  
First Time

All-dielectric superlens made from micro and nano particles has emerged as a simple yet effective solution to label-free, super-resolution imaging. High-index BaTiO3 Glass (BTG) microspheres are among the most widely used dielectric superlenses today but could potentially be replaced by a new class of TiO2 metamaterial (meta-TiO2) superlens made of TiO2 nanoparticles. In this work, we designed and fabricated TiO2 metamaterial superlens in full-sphere shape for the first time, which resembles BTG microsphere in terms of the physical shape, size, and effective refractive index. Super-resolution imaging performances were compared using the same sample, lighting, and imaging settings. The results show that TiO2 meta-superlens performs consistently better over BTG superlens in terms of imaging contrast, clarity, field of view, and resolution, which was further supported by theoretical simulation. This opens new possibilities in developing more powerful, robust, and reliable super-resolution lens and imaging systems.

scholarly journals Global architecture of the nucleus in single cells by DNA seqFISH+ and multiplexed immunofluorescence

2020 ◽  
Author(s):  
Yodai Takei ◽  
Jina Yun ◽  
Noah Ollikainen ◽  
Shiwei Zheng ◽  
Nico Pierson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Single Cells ◽  
Hidden Variables ◽  
Embryonic Stem ◽  
Super Resolution ◽  
Molecular Heterogeneity ◽  
Organization Studies ◽  
Chromatin States ◽  
Resolution Imaging ◽  
Nascent Transcripts

AbstractIdentifying the relationships between chromosome structures, chromatin states, and gene expression is an overarching goal of nuclear organization studies. Because individual cells are highly variable at all three levels, it is essential to map all three modalities in the same single cell, a task that has been difficult to accomplish with existing tools. Here, we report the direct super-resolution imaging of over 3,660 chromosomal loci in single mouse embryonic stem cells (mESCs) by DNA seqFISH+, along with 17 chromatin marks by sequential immunofluorescence (IF) and the expression profile of 70 RNAs, in the same cells. We discovered that the nucleus is separated into zones defined by distinct combinatorial chromatin marks. DNA loci and nascent transcripts are enriched at the interfaces between specific nuclear zones, and the level of gene expression correlates with an association between active or nuclear speckle zones. Our analysis also uncovered several distinct mESCs subpopulations with characteristic combinatorial chromatin states that extend beyond known transcriptional states, suggesting that the metastable states of mESCs are more complex than previously appreciated. Using clonal analysis, we show that the global levels of some chromatin marks, such as H3K27me3 and macroH2A1 (mH2A1), are heritable over at least 3-4 generations, whereas other marks fluctuate on a faster time scale. The long-lived chromatin states may represent “hidden variables” that explain the observed functional heterogeneity in differentiation decisions in single mESCs. Our integrated spatial genomics approach can be used to further explore the existence and biological relevance of molecular heterogeneity within cell populations in diverse biological systems.

AIE opens new applications in super-resolution imaging

2016 ◽  
Vol 4 (48) ◽  
pp. 7761-7765 ◽  
Author(s):  
Jiong Zhou ◽  
Guocan Yu ◽  
Feihe Huang
Keyword(s):  
Recent Work ◽  
Super Resolution ◽  
New Class ◽  
Turn On ◽  
Resolution Imaging ◽  
Fluorescence Turn On ◽  
New Applications

In a recent work, Tang and co-workers reported a new class of photoactivatable fluorescence turn-on AIE-based bioprobes which can be used for super-resolution imaging of mitochondria. This result opens a new door in the field of super-resolution imaging for developing a novel AIE-based bioprobe with high on–off contrast and a fast photoswitching rate.

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