Activating Photoactivatable Proteins with Laser Light to Visualize Membrane Systems and Membrane Traffic in Living Cells

2011 ◽  
Vol 2011 (11) ◽  
pp. pdb.prot066571-pdb.prot066571
Author(s):  
E. L. Snapp ◽  
P. Lajoie
Keyword(s):  
Laser Light ◽  
Membrane Traffic ◽  
Living Cells ◽  
Membrane Systems ◽  
Photoactivatable Proteins

Imaging of Organelle Membrane Systems and Membrane Traffic in Living Cells

2006 ◽  
Vol 2006 (6) ◽  
pp. pdb.prot4603-pdb.prot4603
Author(s):  
J. Lippincott-Schwartz ◽  
E. L. Snapp
Keyword(s):  
Membrane Traffic ◽  
Living Cells ◽  
Membrane Systems ◽  
Organelle Membrane

scholarly journals Imaging of Membrane Systems and Membrane Traffic in Living Cells

2011 ◽  
Vol 2011 (11) ◽  
pp. pdb.top066548-pdb.top066548
Author(s):  
E. L. Snapp ◽  
P. Lajoie
Keyword(s):  
Membrane Traffic ◽  
Living Cells ◽  
Membrane Systems

Dual-color visualization of trans-Golgi network to plasma membrane traffic along microtubules in living cells

1999 ◽  
Vol 112 (1) ◽  
pp. 21-33 ◽  
Author(s):  
D. Toomre ◽  
P. Keller ◽  
J. White ◽  
J.C. Olivo ◽  
K. Simons
Keyword(s):  
Plasma Membrane ◽  
Protein Trafficking ◽  
Membrane Traffic ◽  
Living Cells ◽  
Tubular Structures ◽  
Trans Golgi Network ◽  
Vesicular Stomatitis ◽  
Golgi Network ◽  
Color Visualization

The mechanisms and carriers responsible for exocytic protein trafficking between the trans-Golgi network (TGN) and the plasma membrane remain unclear. To investigate the dynamics of TGN-to-plasma membrane traffic and role of the cytoskeleton in these processes we transfected cells with a GFP-fusion protein, vesicular stomatitis virus G protein tagged with GFP (VSVG3-GFP). After using temperature shifts to block VSVG3-GFP in the endoplasmic reticulum and subsequently accumulate it in the TGN, dynamics of TGN-to-plasma membrane transport were visualized in real time by confocal and video microscopy. Both small vesicles (<250 nm) and larger vesicular-tubular structures (>1.5 microm long) are used as transport containers (TCs). These TCs rapidly moved out of the Golgi along curvilinear paths with average speeds of approximately 0.7 micrometer/second. Automatic computer tracking objectively determined the dynamics of different carriers. Fission and fusion of TCs were observed, suggesting that these late exocytic processes are highly interactive. To directly determine the role of microtubules in post-Golgi traffic, rhodamine-tubulin was microinjected and both labeled cargo and microtubules were simultaneously visualized in living cells. These studies demonstrated that exocytic cargo moves along microtubule tracks and reveals that carriers are capable of switching between tracks.

Optical 3D Manipulation and Observation in Real-Time

2006 ◽  
Vol 18 (6) ◽  
pp. 692-697 ◽  
Author(s):  
Jesper Glückstad ◽  
◽  
Peter John Rodrigo ◽  
Ivan Perch-Nielsen
Keyword(s):  
Real Time ◽  
Phase Contrast ◽  
Spatial Light Modulator ◽  
Laser Light ◽  
National Laboratory ◽  
Three Dimensional ◽  
Living Cells ◽  
Promising Technique ◽  
Light Modulator ◽  
3D Manipulation

Three-dimensional light structures can be created by modulating the spatial phase and polarization properties of the laser light. A particularly promising technique is the Generalized Phase Contrast (GPC) method invented and patented at Risø National Laboratory. Based on the combination of programmable spatial light modulator devices and an advanced graphical user-interface the GPC method enables real-time, interactive and arbitrary control over the dynamics and geometry of synthesized light patterns. Recent experiments have shown that GPC-driven micro-manipulation provides a unique technology platform for fully user-guided assembly of a plurality of particles in a plane, control of particle stacking along the beam axis, manipulation of multiple hollow beads, and the organization of living cells into three-dimensional colloidal structures. These demonstrations illustrate that GPC-driven micro-manipulation can be utilized not only for the improved synthesis of functional microstructures but also for non-contact and parallel actuation crucial for sophisticated opto- and micro-fluidic based lab-on-a-chip systems.

Behaviour of kinetochore fibres in Haemanthus katherinae during anaphase movements of chromosomes

1977 ◽  
Vol 27 (1) ◽  
pp. 47-56
Author(s):  
R. Hard ◽  
R.D. Allen
Keyword(s):  
Light Source ◽  
Laser Light ◽  
Living Cells ◽  
Differential Interference Contrast ◽  
Chromosome Movement ◽  
Lateral Interactions ◽  
Parallel Orientation ◽  
Early Anaphase ◽  
Laser Light Source ◽  
Dic Microscopy

A laser light source along with a new method of preparing endosperm cells of Haemanthus katherinae for differential interference contrast (DIC) microscopy has led to increased visibility of kinetochore fibres. Little information is available concerning the behaviour of these fibres during anaphase in living cells. In metaphase, kinetochore fibres are seen as distinct bundles of microtubules, here referred to as ‘filaments’, extending from the kinetochore to the ‘diffuse’ pole. They possess an apparent globular substructure which corresponds to the moving ‘particles or states’ described previously from cine films. In early anaphase, the filaments of each kinetochore fibre lose their parallel orientation characteristic of metaphase and splay out so that the more peripheral filaments intermingle with those of other kinetochore fibres. This process begins at the poles and proceeds as a wave toward the kinetochores as chromosomal movement progresses. This behaviour has been examined in relation to a number of proposed models for the mechanism of chromosome movement and has been found to place some constraints on some models but to be consistent with any model that hypothesizes that chromosomes move as a consequence of cumulative cohesive lateral interactions of microtubules.

scholarly journals Targeted Chemical Disruption of Clathrin Function in Living Cells

2003 ◽  
Vol 14 (11) ◽  
pp. 4437-4447 ◽  
Author(s):  
Howard S. Moskowitz ◽  
John Heuser ◽  
Timothy E. McGraw ◽  
Timothy A. Ryan
Keyword(s):  
Gene Expression ◽  
Fusion Protein ◽  
Time Scales ◽  
Membrane Traffic ◽  
Living Cells ◽  
Normal Function ◽  
Fk506 Binding Protein ◽  
Important Protein ◽  
Cross Linker ◽  
Specific Inhibitors

The accurate assignment of molecular roles in membrane traffic is frequently complicated by the lack of specific inhibitors that can work on rapid time scales. Such inhibition schemes would potentially avoid the complications arising from either compensatory gene expression or the complex downstream consequences of inhibition of an important protein over long periods (>12 h). Here, we developed a novel chemical tool to disrupt clathrin function in living cells. We engineered a cross-linkable form of clathrin by using an FK506-binding protein 12 (FKBP)-clathrin fusion protein that is specifically oligomerized upon addition of the cell-permeant cross-linker FK1012-A. This approach interrupts the normal assembly-disassembly cycle of clathrin lattices and results in a specific, rapid, and reversible ∼70% inhibition of clathrin function. This approach should be applicable to a number of proteins that must go through an assembly-disassembly cycle for normal function.

Simple Neural-Like P Systems for Maximal Independent Set Selection

2013 ◽  
Vol 25 (6) ◽  
pp. 1642-1659 ◽  
Author(s):  
Lei Xu ◽  
Peter Jeavons
Keyword(s):  
Distributed Computing ◽  
Membrane Computing ◽  
Independent Set ◽  
Living Cells ◽  
P Systems ◽  
Maximal Independent Set ◽  
Membrane Systems ◽  
New Class ◽  
The Individual ◽  
Computing Models

Membrane systems (P systems) are distributed computing models inspired by living cells where a collection of processors jointly achieves a computing task. The problem of maximal independent set (MIS) selection in a graph is to choose a set of nonadjacent nodes to which no further nodes can be added. In this letter, we design a class of simple neural-like P systems to solve the MIS selection problem efficiently in a distributed way. This new class of systems possesses two features that are attractive for both distributed computing and membrane computing: first, the individual processors do not need any information about the overall size of the graph; second, they communicate using only one-bit messages.

scholarly journals The dynamic cell: Livecell imaging and membrane traffic pathways

2010 ◽  
Vol 32 (3) ◽  
pp. 4-7
Author(s):  
Mark Jepson ◽  
Paul Verkade ◽  
Paul Martin ◽  
George Banting
Keyword(s):  
Mammalian Cell ◽  
Nuclear Architecture ◽  
Membrane Traffic ◽  
Living Cells ◽  
Cellular Organization ◽  
Subcellular Organelles ◽  
Dynamic Cell ◽  
Static Images

Text books published 15 or more years ago presented lovely cartoons to illustrate the organization of a mammalian cell, highlighting the different subcellular organelles, the cytoskeletal components and the nuclear architecture. Many still do, but the better ones complement these static images with animations and/or movies from imaging of living cells (see Figure 1). The cartoons provide a reason able overview of cellular organization, but they cannot capture the fact that cells are highly dynamic entities with ongoing constitutive and regulated movement between compartments.

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