There are three main types of intercellular junctions: gap junctions, tight junctions, and anchoring junctions. Gap junctions allow communication between cells through channels that connect adjacent cell membranes. Tight junctions form a continuous seal around cells to prevent fluid leakage between them. Anchoring junctions attach cells to each other and to extracellular matrices through proteins like cadherins, integrins, and intermediate filaments. The three types of anchoring junctions are desmosomes, hemidesmosomes, and adherens junctions.

1. Intercellular Junction
Presented By:
14-ARID-2022
FAISAL SHAHZAD SOMROO
Presented To:
Dr. Riaz Hussain Pasha

2. Intercellular junctions
• A cell junction is a type of structure that exists
within the tissue of some multicellular organisms.
• specializations of the cellular margins that
contribute to the adhesion or allow for
communication between cells.
• Mostly found in epithelial tissues.

3. CONT…
There are three main types:
• Gap junction (nexus).
• Tight junction (zonula occludens)
• Anchoring junction
-Desmosome (macula adherens)
-Hemidesmosome
-Adheren (zonula adherens)

5. Gap Junction:
• It is a communicating junction.
• Gap junctions consist of intercellular channels in
the plasma membrane of adjacent cells.
• Consist of six connexon proteins arranged to form
a doughnut shape structure.
• Play role in cardiac muscle contraction.

6. Cont…
• Helps in signal transfer in brain.
• Their size vary in different cells.

8. Tight Junction:
• The borders of two cells are fused together, often around the
whole perimeter of each cell, forming a continuous belt like
junction known as a tight junction or zonula occludens (zonula =
latin for belt).
• ZO-1 & ZO-2 Link transmembrane proteins (Occludin and
Clauding) with Spectrin.
• Prevent leakage of fluid.
• Found in the apical region around the cell's circumference.

9. Cont…
• It prevent mobility of transmembrane proteins.
• It regulate the movement of water and solutes
between epithelial layer.
• Lines the gastrointestinal tract.

12. Anchoring Junction:
• Cells within tissues anchor to one another and
to extracellular fluid.
• There are following three types:
1. Desmosomes Junction
2. Hemidesmosomes Junction
3. Adherens Juntion

13. Cont..
Junction Cytoskeletal
Anchor
Transmembrane
Linker
Ties cell to
Desmosomes Intermediate
Filaments
Cadherin Cell
Hemidesmosome Intermediate
Filaments
Integrins ECF
Adherens
Junction
Actin Filaments Cadherin/Integri
ns
Cell/ECF

14. Desmosomes:
• Form cell to cell junction.
• Known as Maculae adherens.
• Intracellular adaptor proteins connect to
intermediate filament and form cytoplasmic
plaque.
• Cadherin joins the cytoplasmic plaques of two
cells.

15. Cont…
• The gap b/w this junction is 30nm
• Found in epidermis of skin and muscle tissues.
• Blistering diseases.
• Pemphigus.
• Hailey-Hailey disease.

17. Hemidesmosomes:
• Connect cell to extracellular fluid.
• Connect epithelial cells to basement
membrane.
• Integrins are the linking proteins.
• Present in epidermis of skin.
• Epidermolysis bullosa.

19. Adheren Junction:
• Junctions which form junction b/w cell to cell.
• Also known as Zonulae adherens.
• Lies basal to tight junction.
• Microfilaments of two cells are connected by cadherins.
• Cytoplasmic face is linked to actin cytoskeleton.
• Actin myosin interaction can change the shape of the
epithelium.