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Here is a comprehensive mind map on the topic of "Cell Junction" in Physiology:
Central Idea: Cell Junction
Main Branches:
- Types of Cell Junctions
- Structure of Cell Junctions
- Functions of Cell Junctions
- Regulation of Cell Junctions
- Diseases Associated with Cell Junctions
Sub-branches:
Types of Cell Junctions:
Tight Junctions
- Characteristics: Impermeable, occluding, and adherens junctions that seal adjacent cells together
- Functions: Prevents leakage of molecules across the epithelial or endothelial barrier, maintains cell polarity
- Examples: Blood-brain barrier, intestinal epithelium, kidney glomeruli
Adherens Junctions
- Characteristics: Mediates cell-cell adhesion, anchors actin cytoskeleton to the membrane
- Functions: Maintains tissue architecture, regulates cell migration and differentiation
- Examples: Epithelial cells, endothelial cells, fibroblasts
Desmosomes
- Characteristics: Button-like structures that hold adjacent cells together
- Functions: Provides mechanical strength, resists shear forces, and maintains tissue integrity
- Examples: Epithelial cells, cardiac muscle cells, skin cells
Gap Junctions
- Characteristics: Allows direct communication between adjacent cells, enables ion and metabolite exchange
- Functions: Coordinates cellular behavior, regulates electrical activity, and maintains tissue homeostasis
- Examples: Cardiac muscle cells, smooth muscle cells, neurons
Hemidesmosomes
- Characteristics: Half-desmosomes that anchor cells to the basement membrane
- Functions: Maintains tissue architecture, regulates cell migration and differentiation
- Examples: Epithelial cells, endothelial cells, fibroblasts
Focal Adhesions
- Characteristics: Dynamic structures that mediate cell-matrix adhesion and signaling
- Functions: Regulates cell migration, differentiation, and survival, and maintains tissue architecture
- Examples: Fibroblasts, epithelial cells, endothelial cells
Structure of Cell Junctions:
- Protein Composition
Tight Junctions
- Occludin: a transmembrane protein that forms the tight junction seal
- Claudins: a family of transmembrane proteins that regulate paracellular permeability
- Junctional adhesion molecules (JAMs): a family of transmembrane proteins that regulate cell-cell adhesion
- Zonula occludens (ZO) proteins: a family of cytosolic proteins that link occludin and claudins to the actin cytoskeleton
Adherens Junctions
- E-cadherin: a transmembrane protein that mediates cell-cell adhesion
- β-catenin: a cytosolic protein that links E-cadherin to the actin cytoskeleton
- α-catenin: a cytosolic protein that regulates the interaction between E-cadherin and β-catenin
- P120 catenin: a cytosolic protein that regulates the interaction between E-cadherin and the actin cytoskeleton
Desmosomes
- Desmogleins: a family of transmembrane proteins that mediate cell-cell adhesion
- Desmocollins: a family of transmembrane proteins that regulate desmosome assembly
- Plakoglobin: a cytosolic protein that links desmogleins and desmocollins to the intermediate filament cytoskeleton
- Plakophilins: a family of cytosolic proteins that regulate desmosome assembly and stability
Gap Junctions
- Connexins: a family of transmembrane proteins that form gap junction channels
- Connexin-43: a widely expressed connexin that forms gap junctions in many tissues
- Connexin-32: a connexin that forms gap junctions in the liver and other tissues
- Connexin-26: a connexin that forms gap junctions in the cochlea and other tissues
Hemidesmosomes
- Integrin α6β4: a transmembrane protein that mediates cell-matrix adhesion
- Plectin: a cytosolic protein that links integrin α6β4 to the intermediate filament cytoskeleton
- BP180: a transmembrane protein that regulates hemidesmosome assembly and stability
- BP230: a cytosolic protein that regulates hemidesmosome assembly and stability
Focal Adhesions
- Integrin β1: a transmembrane protein that mediates cell-matrix adhesion
- Focal adhesion kinase (FAK): a cytosolic protein that regulates focal adhesion assembly and signaling
- Paxillin: a cytosolic protein that regulates focal adhesion assembly and signaling
- Talin: a cytosolic protein that regulates focal adhesion assembly and signaling
- Lipid Composition
- Phospholipids
- Cholesterol
- Sphingolipids
- Cell Adhesion Molecules
- Cadherins
- Integrins
- Selectins
- Cytoskeleton
- Actin filaments
- Microtubules
- Intermediate filaments
Functions of Cell Junctions:
- Cell-Cell Adhesion
- Tight junctions
- Adherens junctions
- Desmosomes
- Cell Signaling
- Gap junctions
- Tight junctions
- Adherens junctions
- Barrier Function
- Tight junctions
- Adherens junctions
- Desmosomes
- Mechanical Coupling
- Desmosomes
- Adherens junctions
- Focal adhesions
Regulation of Cell Junctions:
- Signal Transduction Pathways
- MAPK pathway
- PI3K/Akt pathway
- JAK/STAT pathway
- Transcription Factors
- NF-κB
- AP-1
- NFAT
- Post-Translational Modifications
- Phosphorylation
- Ubiquitination
- Sumoylation
- MicroRNAs
- Regulation of cell junctions
- Targets of microRNAs
Diseases Associated with Cell Junctions:
- Cancer
- Tight junctions
- Adherens junctions
- Desmosomes
- Inflammatory Diseases
- Tight junctions
- Adherens junctions
- Desmosomes
- Neurological Disorders
- Gap junctions
- Tight junctions
- Adherens junctions
- Cardiovascular Diseases
- Gap junctions
- Tight junctions
- Adherens junctions
This mind map provides a comprehensive overview of cell junctions, covering their types, structure, functions, regulation, and diseases associated with them.
