Grieneisen_DynamicalCell_Lecture2024
Biology Notes
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Speaker: Verônica A. Grieneisen from Cardiff University, UK
Topic: Systems Biology of the Cell
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Cells need to:
Divide and know when to stop
Move to other places and stay put
Differentiate into the appropriate cell type
Function physiologically and biophysically
To achieve the above, cells need to communicate, stick together, and become polar.
auto-organisation and regeneration
the hydra species can regeneration
it is very simple as well as it has an outer and inner cell layer.
auto-organisation
page 6???
how can we understand the auto-organisation and cell sorting
cell have adhesion they can exhibit differential adhesion.
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Differential Adhesion Hypothesis:
Proposed by Steinberg in 1963 that cell sorting could be explained as driven by differential adhesion cell type within tissue.
Cell sorting is driven by differential adhesion between cell types in a tissue
Cells with higher adhesion form tissues with higher surface tension
bekijk de bladzijde tien nog een keer want je begrijpt het niet
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In silico Cell Modelling:
Using computer models to test hypotheses
Cellular Potts Model invented by Graner & Glaziar in 1992
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green arrow represents the adhesion drive
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In Silico Cells:
Non-polar with small membrane fluctuations
Cells round up alone but form honey-comb lattice shapes when in contact with others
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Adhesion Mechanisms:
Mediated by cadherins expressed on cell membranes
Two-tiered mechanism for stabilization and immobilization of E-cadherin
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Key Messages:
adhesion differences between different cell types will lead to tissue seperating or “auto-organising“
Computer models can test hypotheses
Auto-organisation follows simple rules driven by adhesion differences
complex plant morphology
gene regulatory
plant-soil interaction
environmental condition
ecological interaction
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Auxin:
Indole-3-acetic acid
Regulates cell division, differentiation, and elongation
auxin move through specialised membrane transporter
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Auxin Gradients:
Instructive for development
Stable growth due to dynamic auxin flows
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Learnings:
Coordinated transporter direction organizes roots
Dynamic auxin flows lead to stable growth and provide instructions
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Complexity of Cells:
Cells are more complex than simple rules suggest
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Keratocyte:
A single moving cell discussed
Conclusion
The study of cell dynamics, adhesion, and modeling plays a crucial role in understanding cell behavior and organization.
Biology Notes
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Main Ideas:
Actin cytoskeleton in animal cells plays a role in cell deformation and motility.
Involvement of G-actin, F-actin, and sidebranching by Arp2/3.
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Main Ideas:
Core internal cell dynamics in animal cells involve Cdc42, Rac, Rho, WASp, WAVE, PIP2, ROCK, Arp2/3, capping, and contraction protein.
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Main Ideas:
Continuation of core internal cell dynamics in animal cells with a focus on front and back dynamics involving Cdc42, Rac, Rho, WASp, WAVE, PIP2, ROCK, Arp2/3, capping, and contraction protein.
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Main Ideas:
Small G-proteins act as molecular switches with GTP and GDP.
Involvement of GEF, Rho, Rho GDP, GTP, GDI, GAP, and effectors in G-protein signalling.
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Main Ideas:
Polarity in animal cells with Rac and Cdc42 at the front and Rho at the back.
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Main Ideas:
Systems biology approach to understanding cell dynamics.
Crosstalk between G-proteins through GEFs and the role of GTP and GDP in signaling pathways.
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Main Ideas:
Small G-protein interactions contribute to polarity in cells.
Importance of fast cytosolic diffusion and slow membrane diffusion.
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Main Ideas:
Cells exhibit movement due to reactions between proteins and differential diffusion.
Patterns can emerge without external cues based on protein interactions.
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Main Ideas:
Steering of the cytoskeleton by small G-proteins like Rho, Rac, and Cdc42.
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Main Ideas:
Dynamic spatial settings in cell biology research.
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Main Ideas:
Integration of systems biology in understanding cell dynamics in a dynamic spatial setting.
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Main Ideas:
Evaluation of the effectiveness of biological models in learning new insights.
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Main Ideas:
Learning from cellular processes that deviate from the norm, such as interactions when cells encounter obstacles.
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Main Ideas:
Exploration of conflicts and resolutions involving small G-proteins like Cdc42, Rac, and Rho.
Involvement of cytoskeleton components like Arp2/3, capping, and contraction in cell dynamics.
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Main Ideas:
Utilizing cell biochemistry to understand cell shape, movement, sensitivity, and conflict resolution.
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Main Ideas:
Individual cell behavior in the context of cellular models.
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Main Ideas:
Collective behavior of multiple model cells influenced by spatial constraints rather than signaling pathways.
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Main Ideas:
Cells organize through properties like adhesion, polarity, and communication.
Use of models to explore interactions between different levels in biology.
Examples of cell sorting, plant morphogenesis, and shared mechanisms in animal and plant cells.
Importance of imaging and systems biology thinking in understanding cellular processes.
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Main Ideas:
Plant cells also exhibit polarity and steering mechanisms similar to animal cells.
Studies