scholarly journals A Combinatorial MAP Code Dictates Polarized Microtubule Transport

2020 ◽  
Vol 53 (1) ◽  
pp. 60-72.e4 ◽  
Author(s):  
Brigette Y. Monroy ◽  
Tracy C. Tan ◽  
Janah May Oclaman ◽  
Jisoo S. Han ◽  
Sergi Simó ◽  
...  
Keyword(s):  
Microtubule Transport

scholarly journals Region-Specific Microtubule Transport in Motile Cells

2000 ◽  
Vol 151 (5) ◽  
pp. 1003-1012 ◽  
Author(s):  
Anne-Marie C. Yvon ◽  
Patricia Wadsworth
Keyword(s):  
Growth Factor ◽  
Cell Motility ◽  
Cell Body ◽  
Dependent Manner ◽  
Retrograde Flow ◽  
Cell Locomotion ◽  
Quantitative Measurements ◽  
Motile Cells ◽  
Microtubule Transport ◽  
Hepatocyte Growth

Photoactivation and photobleaching of fluorescence were used to determine the mechanism by which microtubules (MTs) are remodeled in PtK2 cells during fibroblast-like motility in response to hepatocyte growth factor (HGF). The data show that MTs are transported during cell motility in an actomyosin-dependent manner, and that the direction of transport depends on the dominant force in the region examined. MTs in the leading lamella move rearward relative to the substrate, as has been reported in newt cells (Waterman-Storer, C.M., and E.D. Salmon. 1997. J. Cell Biol. 139:417–434), whereas MTs in the cell body and in the retraction tail move forward, in the direction of cell locomotion. In the transition zone between the peripheral lamella and the cell body, a subset of MTs remains stationary with respect to the substrate, whereas neighboring MTs are transported either forward, with the cell body, or rearward, with actomyosin retrograde flow. In addition to transport, the photoactivated region frequently broadens, indicating that individual marked MTs are moved either at different rates or in different directions. Mark broadening is also observed in nonmotile cells, indicating that this aspect of transport is independent of cell locomotion. Quantitative measurements of the dissipation of photoactivated fluorescence show that, compared with MTs in control nonmotile cells, MT turnover is increased twofold in the lamella of HGF-treated cells but unchanged in the retraction tail, demonstrating that microtubule turnover is regionally regulated.

scholarly journals RPGR-ORF15, Which Is Mutated in Retinitis Pigmentosa, Associates with SMC1, SMC3, and Microtubule Transport Proteins

2005 ◽  
Vol 280 (39) ◽  
pp. 33580-33587 ◽  
Author(s):  
Hemant Khanna ◽  
Toby W. Hurd ◽  
Concepcion Lillo ◽  
Xinhua Shu ◽  
Sunil K. Parapuram ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Transport Proteins ◽  
Microtubule Transport

scholarly journals Elucidating the mechanism of cellular uptake of fullerene nanoparticles

2021 ◽  
Vol 27 (2) ◽  
pp. 200658-0
Author(s):  
Yeonjeong Ha ◽  
Xianzhe Wang ◽  
Howard M. Liljestrand ◽  
Jennifer A. Maynard ◽  
Lynn E. Katz
Keyword(s):  
Active Transport ◽  
Cellular Uptake ◽  
Lipid Membranes ◽  
Culture Media ◽  
Passive Diffusion ◽  
Engineered Nanoparticles ◽  
Metabolic Inhibitors ◽  
Representative Cell ◽  
Fullerene Concentration ◽  
Microtubule Transport

Understanding the molecular interactions between biological cells and engineered nanoparticles is a key to evaluating potential toxicities to humans and the environment. This study developed a method to determine the mechanisms by which fullerene aggregates are distributed into a representative cell line, human intestinal Caco-2 cells. First, we determined that the presence of fetal bovine serum (FBS) in the cell culture media changes the particle characteristics and inhibits particle adsorptions onto cell surfaces. Second, significantly lower amounts of fullerene were internalized at 4°C, a temperature at which active transport mechanisms are effectively impeded, than at 37°C. Third, metabolic inhibitors of active transport and a microtubule transport inhibitor decreased fullerene uptake at 37°C. Fourth, cellular uptake of fullerene increased with increasing fullerene concentration, suggesting that passive diffusion into lipid membranes contributed to uptake over the broad concentration range used in this study. Together, these results indicate fullerene transport into cells occurs via two mechanisms: passive diffusion across the lipid bilayer and active transport including microtubule involved endocytosis. The results also suggest that simple physical-chemical partitioning models do not fully describe fullerene uptake, and instead, active transport models are also required to estimate the cellular uptake and toxicity of fullerene.

scholarly journals Quantitative Analysis of Microtubule Transport in Growing Nerve Processes

2004 ◽  
Vol 14 (8) ◽  
pp. 725-730 ◽  
Author(s):  
Yitao Ma ◽  
Dinara Shakiryanova ◽  
Irina Vardya ◽  
Sergey V Popov
Keyword(s):  
Quantitative Analysis ◽  
Microtubule Transport

scholarly journals Microtubule Transport on 3D Biocompatible Nanostructures

2018 ◽  
Vol 114 (3) ◽  
pp. 364a
Author(s):  
Haneen Martinez ◽  
Matthew N. Rush ◽  
Jimin Guo ◽  
Jeff Brinker ◽  
Geroge D. Bachand
Keyword(s):  
Microtubule Transport

scholarly journals Trichoplusia ni Kinesin-1 Associates with Autographa californica Multiple Nucleopolyhedrovirus Nucleocapsid Proteins and Is Required for Production of Budded Virus

2016 ◽  
Vol 90 (7) ◽  
pp. 3480-3495 ◽  
Author(s):  
Siddhartha Biswas ◽  
Gary W. Blissard ◽  
David A. Theilmann
Keyword(s):  
Plasma Membrane ◽  
Trichoplusia Ni ◽  
Autographa Californica ◽  
Nucleocapsid Proteins ◽  
Content Type ◽  
Multiple Nucleopolyhedrovirus ◽  
Microtubule Transport ◽  
Infected Cells ◽  
Budded Virus

ABSTRACTThe mechanism by which nucleocapsids ofAutographa californicamultiple nucleopolyhedrovirus (AcMNPV) egress from the nucleus to the plasma membrane, leading to the formation of budded virus (BV), is not known. AC141 is a nucleocapsid-associated protein required for BV egress and has previously been shown to be associated with β-tubulin. In addition, AC141 and VP39 were previously shown by fluorescence resonance energy transfer by fluorescence lifetime imaging to interact directly with theDrosophila melanogasterkinesin-1 light chain (KLC) tetratricopeptide repeat (TPR) domain. These results suggested that microtubule transport systems may be involved in baculovirus nucleocapsid egress and BV formation. In this study, we investigated the role of lepidopteran microtubule transport using coimmunoprecipitation, colocalization, yeast two-hybrid, and small interfering RNA (siRNA) analyses. We show that nucleocapsid AC141 associates with the lepidopteranTrichoplusia niKLC and kinesin-1 heavy chain (KHC) by coimmunoprecipitation and colocalization. Kinesin-1, AC141, and microtubules colocalized predominantly at the plasma membrane. In addition, the nucleocapsid proteins VP39, FP25, and BV/ODV-C42 were also coimmunoprecipitated withT. niKLC. Direct analysis of the role ofT. nikinesin-1 by downregulation of KLC by siRNA resulted in a significant decrease in BV production. Nucleocapsids labeled with VP39 fused with three copies of the mCherry fluorescent protein also colocalized with microtubules. Yeast two-hybrid analysis showed no evidence of a direct interaction between kinesin-1 and AC141 or VP39, suggesting that either other nucleocapsid proteins or adaptor proteins may be required. These results further support the conclusion that microtubule transport is required for AcMNPV BV formation.IMPORTANCEIn two key processes of the replication cycle of the baculovirusAutographa californicamultiple nucleopolyhedrovirus (AcMNPV), nucleocapsids are transported through the cell. These include (i) entry of budded virus (BV) into the host cell and (ii) egress and budding of nucleocapsids newly produced from the plasma membrane. Prior studies have shown that the entry of nucleocapsids involves the polymerization of actin to propel nucleocapsids to nuclear pores and entry into the nucleus. For the spread of infection, progeny viruses must rapidly exit the infected cells, but the mechanism by which AcMNPV nucleocapsids traverse the cytoplasm is unknown. In this study, we examined whether nucleocapsids interact with lepidopteran kinesin-1 motor molecules and are potentially carried as cargo on microtubules to the plasma membrane in AcMNPV-infected cells. This study indicates that microtubule transport is utilized for the production of budded virus.

scholarly journals HDAC6 mediates an aggresome-like mechanism for NLRP3 and pyrin inflammasome activation

Science ◽  
2020 ◽  
Vol 369 (6510) ◽  
pp. eaas8995 ◽  
Author(s):  
Venkat Giri Magupalli ◽  
Roberto Negro ◽  
Yuzi Tian ◽  
Arthur V. Hauenstein ◽  
Giuseppe Di Caprio ◽  
...  
Keyword(s):  
Immune Surveillance ◽  
Inflammasome Activation ◽  
Histone Deacetylase 6 ◽  
Microtubule Organizing Center ◽  
Pyrin Domain ◽  
Microtubule Transport ◽  
Organizing Center ◽  
Aggresome Formation ◽  
Inflammatory Caspases

Inflammasomes are supramolecular complexes that play key roles in immune surveillance. This is accomplished by the activation of inflammatory caspases, which leads to the proteolytic maturation of interleukin 1β (IL-1β) and pyroptosis. Here, we show that nucleotide-binding domain, leucine-rich repeat, and pyrin domain–containing protein 3 (NLRP3)- and pyrin-mediated inflammasome assembly, caspase activation, and IL-1β conversion occur at the microtubule-organizing center (MTOC). Furthermore, the dynein adapter histone deacetylase 6 (HDAC6) is indispensable for the microtubule transport and assembly of these inflammasomes both in vitro and in mice. Because HDAC6 can transport ubiquitinated pathological aggregates to the MTOC for aggresome formation and autophagosomal degradation, its role in NLRP3 and pyrin inflammasome activation also provides an inherent mechanism for the down-regulation of these inflammasomes by autophagy. This work suggests an unexpected parallel between the formation of physiological and pathological aggregates.

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