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
2011 ◽  
Vol 2011 (11) ◽  
pp. pdb.top066548-pdb.top066548
Author(s):  
E. L. Snapp ◽  
P. Lajoie

1999 ◽  
Vol 112 (1) ◽  
pp. 21-33 ◽  
Author(s):  
D. Toomre ◽  
P. Keller ◽  
J. White ◽  
J.C. Olivo ◽  
K. Simons

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.


2020 ◽  
Vol 16 (12) ◽  
pp. 1361-1367 ◽  
Author(s):  
Tomonori Tamura ◽  
Alma Fujisawa ◽  
Masaki Tsuchiya ◽  
Yuying Shen ◽  
Kohjiro Nagao ◽  
...  

2003 ◽  
Vol 14 (11) ◽  
pp. 4437-4447 ◽  
Author(s):  
Howard S. Moskowitz ◽  
John Heuser ◽  
Timothy E. McGraw ◽  
Timothy A. Ryan

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.


2013 ◽  
Vol 25 (6) ◽  
pp. 1642-1659 ◽  
Author(s):  
Lei Xu ◽  
Peter Jeavons

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.


2010 ◽  
Vol 32 (3) ◽  
pp. 4-7
Author(s):  
Mark Jepson ◽  
Paul Verkade ◽  
Paul Martin ◽  
George Banting

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.


2006 ◽  
Vol 17 (01) ◽  
pp. 69-89 ◽  
Author(s):  
MATTEO CAVALIERE ◽  
VINCENZO DEUFEMIA

Membrane systems (currently called P systems) are parallel computing devices inspired by the structure and the functioning of living cells. A standard feature of P systems is that each rule is executed in exactly one time unit. Actually, in living cells different chemical reactions might take different times to be executed; moreover, it might be hard to know precisely such time of execution. For this reason, in [7] two models of P systems (time-free and clock-free P systems) have been defined and investigated, where the time of execution of the rules is arbitrary and the output produced by the system is always the same, independently of this time. Preliminary results concerning time-free and clock-free P system have been obtained in [6, 7, 8]. In this paper we continue these investigations by considering different combinations of possible ingredients. In particular, we present the universality of time-free P systems using bi-stable catalysts. Then, we prove that this result implies that is not possible to decide whether an arbitrary bi-stable catalytic P system is time-free. We present several results about time-free evolution-communication P systems, where the computation is a mixed application of evolution and symport/antiport rules. In this case we obtain the universality even by using non-cooperative evolution rules and antiports of weight one. Finally, we formulate several open problems.


2017 ◽  
Vol 112 (3) ◽  
pp. 224a
Author(s):  
Jonathan D. Nickels ◽  
Sneha Chatterjee ◽  
Christopher Stanley ◽  
Shuo Qian ◽  
Xiaolin Cheng ◽  
...  

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