Microscopic self-organization in living cells: a study of time matching

1995 ◽  
Vol 176 (1) ◽  
pp. 181-184 ◽  
Author(s):  
Benno Hess ◽  
Alexander Mikhailov
Keyword(s):  
Living Cells ◽  
Self Organization

Biochemical topology: From vectorial metabolism to morphogenesis

1991 ◽  
Vol 11 (6) ◽  
pp. 347-385 ◽  
Author(s):  
Franklin M. Harold
Keyword(s):  
Living Cells ◽  
Energy Transduction ◽  
Self Organization ◽  
Cellular Space ◽  
Biochemical Processes ◽  
Cellular Physiology ◽  
Cytoplasmic Transport ◽  
Fungal Hyphae ◽  
Vectorial Metabolism ◽  
Point Of Departure

In living cells, many biochemical processes are spatially organized: they have a location, and often a direction, in cellular space. In the hands of Peter Mitchell and Jennifer Moyle, the chemiosmotic formulation of this principle proved to be the key to understanding biological energy transduction and related aspects of cellular physiology. For H. E. Huxley and A. F. Huxley, it provided the basis for unravelling the mechanism of muscle contraction; and vectorial biochemistry continues to reverberate through research on cytoplasmic transport, motility and organization. The spatial deployment of biochemical processes serves here as a point of departure for an inquiry into morphogenesis and self-organization during the apical growth of fungal hyphae.

Self-organization versus Watchmaker: stochastic dynamics of cellular organization

2005 ◽  
Vol 386 (3) ◽  
pp. 247-254 ◽  
Author(s):  
Alexei Kurakin
Keyword(s):  
Experimental Evidence ◽  
Stochastic Dynamics ◽  
Molecular System ◽  
Living Cells ◽  
Integrated System ◽  
Self Organization ◽  
Cellular Organization ◽  
Time Dynamics ◽  
Design Charts ◽  
Growing Body

AbstractThe cell, as a molecular system, is often interpreted in terms of complex clockworks, and the design charts of mechanical and electrical engineering are assumed to provide adequate approximations for the description of cellular organization. However, a growing body of experimental evidence obtained through the observation and analysis of real-time dynamics of fluorescently labeled molecules inside living cells is increasingly inconsistent with the classico-mechanistic perception of the cell. An overview of recent studies favors an emerging alternative image of the cell as a dynamic integrated system of interconnected and interdependent metastable molecular organizations realized through stochasticity and self-organization.

scholarly journals Unstable Modes and Order Parameters of Bistable Signaling Pathways at Saddle-Node Bifurcations: A Theoretical Study Based on Synergetics

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Till D. Frank
Keyword(s):  
Mathematical Modeling ◽  
Signaling Pathways ◽  
Cell Fate ◽  
Theoretical Study ◽  
Living Cells ◽  
Order Parameters ◽  
Self Organization ◽  
Memory Functions ◽  
Bifurcation Points ◽  
Saddle Node

Mathematical modeling has become an indispensable part of systems biology which is a discipline that has become increasingly popular in recent years. In this context, our understanding of bistable signaling pathways in terms of mathematical modeling is of particular importance because such bistable components perform crucial functions in living cells. Bistable signaling pathways can act as switches or memory functions and can determine cell fate. In the present study, properties of mathematical models of bistable signaling pathways are examined from the perspective of synergetics, a theory of self-organization and pattern formation founded by Hermann Haken. At the heart of synergetics is the concept of so-called unstable modes or order parameters that determine the behavior of systems as a whole close to bifurcation points. How to determine these order parameters for bistable signaling pathways at saddle-node bifurcation points is shown. The procedure is outlined in general and an explicit example is worked out in detail.

scholarly journals A de novo matrix for macroscopic living materials from bacteria

2021 ◽  
Author(s):  
Sara Molinari ◽  
Robert F. Tesoriero ◽  
Dong Li ◽  
Swetha Sridhar ◽  
Rong Cai ◽  
...  
Keyword(s):  
De Novo ◽  
Caulobacter Crescentus ◽  
Living Cells ◽  
Structure And Function ◽  
Self Organization ◽  
Morphological Properties ◽  
Interacting Protein ◽  
And Function ◽  
Assembly Principles ◽  
Living Materials

Engineered living materials (ELMs) embed living cells in a biopolymer matrix to create novel materials with tailored functions. While bottom-up assembly of macroscopic ELMs with a de novo matrix would offer the greatest control over material properties, we lack the ability to genetically encode a protein matrix that leads to collective self-organization. Here we report growth of ELMs from Caulobacter crescentus cells that display and secrete a self-interacting protein. This protein formed a de novo matrix and assembled cells into centimeter-scale ELMs. Discovery of design and assembly principles allowed us to tune the mechanical, catalytic, and morphological properties of these ELMs. This work provides novel tools, design and assembly rules, and a platform for growing ELMs with control over matrix and cellular structure and function.

Self-organization in living cells

Science ◽  
1994 ◽  
Vol 264 (5156) ◽  
pp. 223-224 ◽  
Author(s):  
B Hess ◽  
A Mikhailov
Keyword(s):  
Living Cells ◽  
Self Organization

Self-organization in living cells

1994 ◽  
Vol 98 (9) ◽  
pp. 1198-1201 ◽  
Author(s):  
B. Hess ◽  
A. Mikhailov
Keyword(s):  
Living Cells ◽  
Self Organization

scholarly journals Reversal of contractility as a signature of self-organization in cytoskeletal bundles

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Martin Lenz
Keyword(s):  
Molecular Motors ◽  
Mitotic Spindle ◽  
Living Cells ◽  
Self Organization ◽  
Theoretical Treatment ◽  
Disordered Structures ◽  
Filament Assembly ◽  
Internal Structures ◽  
Microtubule Motor

Bundles of cytoskeletal filaments and molecular motors generate motion in living cells, and have internal structures ranging from very organized to apparently disordered. The mechanisms powering the disordered structures are debated, and existing models predominantly predict that they are contractile. We reexamine this prediction through a theoretical treatment of the interplay between three well-characterized internal dynamical processes in cytoskeletal bundles: filament assembly and disassembly, the attachement-detachment dynamics of motors and that of crosslinking proteins. The resulting self-organization is easily understood in terms of motor and crosslink localization, and allows for an extensive control of the active bundle mechanics, including reversals of the filaments’ apparent velocities and the possibility of generating extension instead of contraction. This reversal mirrors some recent experimental observations, and provides a robust criterion to experimentally elucidate the underpinnings of both actomyosin activity and the dynamics of microtubule/motor assemblies in vitro as well as in diverse intracellular structures ranging from contractile bundles to the mitotic spindle.

Fluorescence ratio imaging of dynamic intracellular ionic signals

1988 ◽  
Vol 46 ◽  
pp. 42-43
Author(s):  
R. Y. Tsien ◽  
A. Minta ◽  
M. Poenie ◽  
J.P.Y. Kao ◽  
A. Harootunian
Keyword(s):  
Binding Sites ◽  
Living Cells ◽  
Molecular Engineering ◽  
Ph Indicators ◽  
Highly Sensitive ◽  
Fluorescence Ratio Imaging ◽  
Ratio Imaging ◽  
Technical Advances ◽  
Indicator Dyes ◽  
Fluorescein Dyes

Recent technical advances now enable the continuous imaging of important ionic signals inside individual living cells with micron spatial resolution and subsecond time resolution. This methodology relies on the molecular engineering of indicator dyes whose fluorescence is strong and highly sensitive to ions such as Ca2+, H+, or Na+, or Mg2+. The Ca2+ indicators, exemplified by fura-2 and indo-1, derive their high affinity (Kd near 200 nM) and selectivity for Ca2+ to a versatile tetracarboxylate binding site3 modeled on and isosteric with the well known chelator EGTA. The most commonly used pH indicators are fluorescein dyes (such as BCECF) modified to adjust their pKa's and improve their retention inside cells. Na+ indicators are crown ethers with cavity sizes chosen to select Na+ over K+: Mg2+ indicators use tricarboxylate binding sites truncated from those of the Ca2+ chelators, resulting in a more compact arrangement of carboxylates to suit the smaller ion.

Application of FRAP and digitized fluorescence microscopy to problems in cell membrane dynamics

1988 ◽  
Vol 46 ◽  
pp. 118-119
Author(s):  
K. Jacobson ◽  
A. Ishihara ◽  
B. Holifield ◽  
F. Zhang
Keyword(s):  
Fluorescence Microscopy ◽  
Cell Biology ◽  
Extended Period ◽  
Dynamic Structure ◽  
Living Cells ◽  
Membrane Dynamics ◽  
Molecular Cell Biology ◽  
Image Averaging ◽  
Single Living Cells ◽  
Single Living

Our laboratory is concerned with understanding the dynamic structure of the plasma membrane with particular reference to the movement of membrane constituents during cell locomotion. In addition to the standard tools of molecular cell biology, we employ both fluorescence recovery after photo- bleaching (FRAP) and digitized fluorescence microscopy (DFM) to investigate individual cells. FRAP allows the measurement of translational mobility of membrane and cytoplasmic molecules in small regions of single, living cells. DFM is really a new form of light microscopy in that the distribution of individual classes of ions, molecules, and macromolecules can be followed in single, living cells. By employing fluorescent antibodies to defined antigens or fluorescent analogs of cellular constituents as well as ultrasensitive, electronic image detectors and video image averaging to improve signal to noise, fluorescent images of living cells can be acquired over an extended period without significant fading and loss of cell viability.

Multimode light microscopy and fluorescence-based reagents as tools for the study of chemical and molecular dynamics of living cells and tissues

1992 ◽  
Vol 50 (1) ◽  
pp. 418-419
Author(s):  
D. L. Taylor
Keyword(s):  
Living Cells ◽  
Cellular Level ◽  
Molecular Techniques ◽  
Cellular Functions ◽  
Macromolecular Assemblies ◽  
Cell Functions ◽  
Molecular Events ◽  
Yield Information ◽  
Full Knowledge ◽  
Structural Methods

Cells function through the complex temporal and spatial interplay of ions, metabolites, macromolecules and macromolecular assemblies. Biochemical approaches allow the investigator to define the components and the solution chemical reactions that might be involved in cellular functions. Static structural methods can yield information concerning the 2- and 3-D organization of known and unknown cellular constituents. Genetic and molecular techniques are powerful approaches that can alter specific functions through the manipulation of gene products and thus identify necessary components and sequences of molecular events. However, full knowledge of the mechanism of particular cell functions will require direct measurement of the interplay of cellular constituents. Therefore, there has been a need to develop methods that can yield chemical and molecular information in time and space in living cells, while allowing the integration of information from biochemical, molecular and genetic approaches at the cellular level.

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