scholarly journals LRRK2 mediates tubulation and vesicle sorting from membrane damaged lysosomes

2020 ◽  
Author(s):  
Luis Bonet-Ponce ◽  
Alexandra Beilina ◽  
Chad D. Williamson ◽  
Eric Lindberg ◽  
Jillian H. Kluss ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Super Resolution ◽  
Adaptor Protein ◽  
Dependent Manner ◽  
Leucine Rich Repeat ◽  
Biological Functions ◽  
New Process ◽  
Sporadic Parkinson’S Disease

ABSTRACTMutations in the leucine rich repeat kinase 2 (LRRK2) gene are a cause of familial and sporadic Parkinson’s disease (PD). Nonetheless, the biological functions of LRRK2 remain incompletely understood. Here, we observed that LRRK2 is recruited to lysosomes that have a ruptured membrane. Using unbiased proteomics, we observed that LRRK2 is able to recruit the motor adaptor protein JIP4 to permeabilized lysosomes in a kinase-dependent manner through the phosphorylation of RAB35 and RAB10. Super-resolution live cell imaging microscopy and FIB-SEM revealed that once at the lysosomal membrane, JIP4 promotes the formation of LAMP1-negative lysosomal tubules that release membranous content from ruptured lysosomes. Released vesicular structures are able to interact with other lysosomes. Thus, we described a new process that uses lysosomal tubulation to release vesicular structures from permeabilized lysosomes. LRRK2 orchestrates this process that we name LYTL (LYsosomal Tubulation/sorting driven by LRRK2) that, given the central role of the lysosome in PD, is likely to be disease relevant.

scholarly journals LRRK2 mediates tubulation and vesicle sorting from lysosomes

2020 ◽  
Vol 6 (46) ◽  
pp. eabb2454 ◽  
Author(s):  
Luis Bonet-Ponce ◽  
Alexandra Beilina ◽  
Chad D. Williamson ◽  
Eric Lindberg ◽  
Jillian H. Kluss ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Super Resolution ◽  
Adaptor Protein ◽  
Dependent Manner ◽  
Proteomic Screen ◽  
Lrrk2 Gene ◽  
New Process ◽  
Sporadic Parkinson’S Disease ◽  
Lysosome Membrane

Genetic variation around the LRRK2 gene affects risk of both familial and sporadic Parkinson’s disease (PD). However, the biological functions of LRRK2 remain incompletely understood. Here, we report that LRRK2 is recruited to lysosomes after exposure of cells to the lysosome membrane–rupturing agent LLOME. Using an unbiased proteomic screen, we identified the motor adaptor protein JIP4 as an LRRK2 partner at the lysosomal membrane. LRRK2 can recruit JIP4 to lysosomes in a kinase-dependent manner via the phosphorylation of RAB35 and RAB10. Using super-resolution live-cell imaging microscopy and FIB-SEM, we demonstrate that JIP4 promotes the formation of LAMP1-negative tubules that release membranous content from lysosomes. Thus, we describe a new process orchestrated by LRRK2, which we name LYTL (LYsosomal Tubulation/sorting driven by LRRK2), by which lysosomal tubulation is used to release vesicles from lysosomes. Given the central role of the lysosome in PD, LYTL is likely to be disease relevant.

scholarly journals GMx33 Associates with the Trans-Golgi Matrix in a Dynamic Manner and Sorts within Tubules Exiting the Golgi

2006 ◽  
Vol 17 (1) ◽  
pp. 511-524 ◽  
Author(s):  
Christopher M. Snyder ◽  
Gonzalo A. Mardones ◽  
Mark S. Ladinsky ◽  
Kathryn E. Howell
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Matrix Proteins ◽  
Dependent Manner ◽  
Tail Region ◽  
Cytoplasmic Face ◽  
Golgi Structure ◽  
Golgi Matrix

The trans-Golgi matrix consists of a group of proteins dynamically associated with the trans-Golgi and thought to be involved in anterograde and retrograde Golgi traffic, as well as interactions with the cytoskeleton and maintenance of the Golgi structure. GMx33 is localized to the cytoplasmic face of the trans-Golgi and is also present in a large cytoplasmic pool. Here we demonstrate that GMx33 is dynamically associated with the trans-Golgi matrix, associating and dissociating with the Golgi in seconds. GMx33 can be locked onto the trans-Golgi matrix by GTPγS, indicating that its association is regulated in a GTP-dependent manner like several other Golgi matrix proteins. Using live-cell imaging we show that GMx33 exits the Golgi associated with tubules and within these tubules GMx33 segregates from transmembrane proteins followed by fragmentation of the tubules into smaller tubules and vesicles. Within vesicles produced by an in vitro budding reaction, GMx33 remains segregated in a matrixlike tail region that sometimes contains Golgin-245. This trans-matrix often links a few vesicles together. Together these data suggest that GMx33 is a member of the trans-Golgi matrix and offer clues regarding the role of the trans-Golgi matrix in sorting and exit from the Golgi.

scholarly journals Dynamic Organization of Chromatin Domains Revealed by Super-Resolution Live-Cell Imaging

2017 ◽  
Vol 67 (2) ◽  
pp. 282-293.e7 ◽  
Author(s):  
Tadasu Nozaki ◽  
Ryosuke Imai ◽  
Mai Tanbo ◽  
Ryosuke Nagashima ◽  
Sachiko Tamura ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Super Resolution ◽  
Live Cell ◽  
Chromatin Domains ◽  
Dynamic Organization

The transmembrane adaptor protein NTAL limits mast cell chemotaxis toward prostaglandin E2

2018 ◽  
Vol 11 (556) ◽  
pp. eaao4354 ◽  
Author(s):  
Ivana Halova ◽  
Monika Bambouskova ◽  
Lubica Draberova ◽  
Viktor Bugajev ◽  
Petr Draber
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Adaptor Protein ◽  
Prostaglandin E ◽  
Dependent Manner ◽  
And Function ◽  
Cell Chemotaxis

Chemotaxis of mast cells is one of the crucial steps in their development and function. Non–T cell activation linker (NTAL) is a transmembrane adaptor protein that inhibits the activation of mast cells and B cells in a phosphorylation-dependent manner. Here, we studied the role of NTAL in the migration of mouse mast cells stimulated by prostaglandin E2 (PGE2). Although PGE2 does not induce the tyrosine phosphorylation of NTAL, unlike IgE immune complex antigens, we found that loss of NTAL increased the chemotaxis of mast cells toward PGE2. Stimulation of mast cells that lacked NTAL with PGE2 enhanced the phosphorylation of AKT and the production of phosphatidylinositol 3,4,5-trisphosphate. In resting NTAL-deficient mast cells, phosphorylation of an inhibitory threonine in ERM family proteins accompanied increased activation of β1-containing integrins, which are features often associated with increased invasiveness in tumors. Rescue experiments indicated that only full-length, wild-type NTAL restored the chemotaxis of NTAL-deficient cells toward PGE2. Together, these data suggest that NTAL is a key inhibitor of mast cell chemotaxis toward PGE2, which may act through the RHOA/ERM/β1-integrin and PI3K/AKT axes.

scholarly journals C. elegans neurons have functional dendritic spines

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Andrea Cuentas-Condori ◽  
Ben Mulcahy ◽  
Siwei He ◽  
Sierra Palumbos ◽  
Mei Zhen ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Dendritic Spines ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Super Resolution ◽  
Live Cell ◽  
Model Organisms ◽  
Spine Density ◽  
C Elegans ◽  
Spine Function

Dendritic spines are specialized postsynaptic structures that transduce presynaptic signals, are regulated by neural activity and correlated with learning and memory. Most studies of spine function have focused on the mammalian nervous system. However, spine-like protrusions have been reported in C. elegans (Philbrook et al., 2018), suggesting that the experimental advantages of smaller model organisms could be exploited to study the biology of dendritic spines. Here, we used super-resolution microscopy, electron microscopy, live-cell imaging and genetics to show that C. elegans motor neurons have functional dendritic spines that: (1) are structurally defined by a dynamic actin cytoskeleton; (2) appose presynaptic dense projections; (3) localize ER and ribosomes; (4) display calcium transients triggered by presynaptic activity and propagated by internal Ca++ stores; (5) respond to activity-dependent signals that regulate spine density. These studies provide a solid foundation for a new experimental paradigm that exploits the power of C. elegans genetics and live-cell imaging for fundamental studies of dendritic spine morphogenesis and function.

scholarly journals Malic Acid Carbon Dots: From Super-resolution Live-Cell Imaging to Highly Efficient Separation

ACS Nano ◽  
2018 ◽  
Vol 12 (6) ◽  
pp. 5741-5752 ◽  
Author(s):  
Bo Zhi ◽  
Yi Cui ◽  
Shengyang Wang ◽  
Benjamin P. Frank ◽  
Denise N. Williams ◽  
...  
Keyword(s):  
Malic Acid ◽  
Carbon Dots ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Super Resolution ◽  
Live Cell ◽  
Efficient Separation ◽  
Highly Efficient

scholarly journals Customizable live-cell imaging chambers for multimodal and multiplex fluorescence microscopy

2020 ◽  
Vol 98 (5) ◽  
pp. 612-623
Author(s):  
Adam Tepperman ◽  
David Jiao Zheng ◽  
Maria Abou Taka ◽  
Angela Vrieze ◽  
Austin Le Lam ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Super Resolution ◽  
Live Cell ◽  
Imaging Modalities ◽  
Experimental Conditions ◽  
Microscopy Imaging ◽  
Glass Coverslip ◽  
Multiple Imaging ◽  
Microscopy Techniques

Using multiple imaging modalities while performing independent experiments in parallel can greatly enhance the throughput of microscopy-based research, but requires the provision of appropriate experimental conditions in a format that meets the optical requirements of the microscope. Although customized imaging chambers can meet these challenges, the difficulty of manufacturing custom chambers and the relatively high cost and design inflexibility of commercial chambers has limited the adoption of this approach. Herein, we demonstrate the use of 3D printing to produce inexpensive, customized, live-cell imaging chambers that are compatible with a range of imaging modalities, including super-resolution microscopy. In this approach, biocompatible plastics are used to print imaging chambers designed to meet the specific needs of an experiment, followed by adhesion of the printed chamber to a glass coverslip, producing a chamber that is impermeant to liquids and that supports the growth and imaging of cells over multiple days. This approach can also be used to produce moulds for casting microfluidic devices made of polydimethylsiloxane. The utility of these chambers is demonstrated using designs for multiplex microscopy, imaging under shear, chemotaxis, and general cellular imaging. Together, this approach represents an inexpensive yet highly customizable approach for producing imaging chambers that are compatible with modern microscopy techniques.

A millisecond structured illumination microscope for super-resolution live cell imaging

2020 ◽  
Vol 13 (4) ◽  
pp. 045002
Author(s):  
Tomu Suzuki ◽  
Shinji Kajimoto ◽  
Narufumi Kitamura ◽  
Mayumi Takano-Kasuya ◽  
Naoko Furusawa ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Super Resolution ◽  
Live Cell ◽  
Structured Illumination

scholarly journals EB1 binding restricts STIM1 translocation to ER–PM junctions and regulates store-operated Ca2+ entry

2018 ◽  
Vol 217 (6) ◽  
pp. 2047-2058 ◽  
Author(s):  
Chi-Lun Chang ◽  
Yu-Ju Chen ◽  
Carlo Giovanni Quintanilla ◽  
Ting-Sung Hsieh ◽  
Jen Liou
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Cellular Functions ◽  
Binding Ability ◽  
Trapping Mechanism ◽  
Spatiotemporal Regulation

The endoplasmic reticulum (ER) Ca2+ sensor STIM1 forms oligomers and translocates to ER–plasma membrane (PM) junctions to activate store-operated Ca2+ entry (SOCE) after ER Ca2+ depletion. STIM1 also interacts with EB1 and dynamically tracks microtubule (MT) plus ends. Nevertheless, the role of STIM1–EB1 interaction in regulating SOCE remains unresolved. Using live-cell imaging combined with a synthetic construct approach, we found that EB1 binding constitutes a trapping mechanism restricting STIM1 targeting to ER–PM junctions. We further showed that STIM1 oligomers retain EB1 binding ability in ER Ca2+-depleted cells. By trapping STIM1 molecules at dynamic contacts between the ER and MT plus ends, EB1 binding delayed STIM1 translocation to ER–PM junctions during ER Ca2+ depletion and prevented excess SOCE and ER Ca2+ overload. Our study suggests that STIM1–EB1 interaction shapes the kinetics and amplitude of local SOCE in cellular regions with growing MTs and contributes to spatiotemporal regulation of Ca2+ signaling crucial for cellular functions and homeostasis.

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