Gap junctions are specialized protein channels that connect adjacent cells and allow communication between them. They are composed of connexin proteins that span the cell membranes and join to form channels between cells. Gap junctions allow small molecules and ions to pass directly between cells to coordinate electrical signaling and metabolic cooperation. They play important roles in tissues like muscle, brain, and heart by facilitating coordinated cell responses.

1. Gap junction and
connexius
By subhrajyoti sahoo

2. introduction
specialised junction are found in all animals tissue
among cells of tissue between cells and is ECM to
allow for cell cell and cell matrix contacts.
Cell junction also found in plants and describe their
is plasmadesmata.
There is three type of cell junction first one is
occulading junction next anchoring junction and last
one is communicating junction.
• The gap junction is included in the communicating
junction

3. Definition
• Gap junction are type of cell junction in which
adjacent cell are connected through protein
channels.
• in cell cell attachments and communication are also
facilitated by certain proteins and which is 2nm to
4nm wide gap is known as gap junction.

4. History
• In 1953 first time the Gap junction is shown by the
transmission electrons microscope (TEM).
• The term gap junction appeared to be coined about
16 years later "circa" 1969 from the 1953 first
scene.

5. Structure of GAP junction
• Structurally gap junction consists of all channels
found which series of 6 proteins subunits are located.
• The channel diameter is about 1.5 to 2nm .
• it forms intracellular pipes through which exchange
certain substance between two adjacent cell takes
place.
• Gap junction on channels formed from two identical
Hemichannels are called hometypic while those with
different channels are heterotypic.
•

6. • Groups of six connexins from a connexon, and two
connexons are put together to form a channels that
molecules can pass through
• Hundred of channels are found together at the site
of gap junction in what is known as gap junction
plaque.

7. Figure:-

8. Fig:-

9. Working mechanism of GAP
junction
• Amp and ca++ can also pass through gap junction to
allow propagation of response to extracellular signals.
• the channels formed by gep junction do not allowed
remain open and that the opening of the pore is
regulated by changes in pH and calcium + + ion
concentration.
• For this cause became gap junction a dynamic in
structure like ion channels.
• During embryogenesis cells are electrical component
due to pass of iron through gap junction

10. Diagram

11. Functions of GAP junction
• The skeletal muscle cells and blood cells in animal tissue
are in communication with their neighbour via gap
junction.
• it is responsible for the transmission of signal required for
the drugs to heav an effect and conversely some drugs
were shown to block gap junction channels.
• In the brain they are concentrated in the cerebellum which
is involved in coordinating rapid nuclear activities.
• In the heart tissue for example gap junction facilitated the
flow of electrical current that causes the heart to beat.

12. About connexius
• One connexin protein has four transmembrane
dominance.
• 6 connexins create one connexon.
• when different connexin s in join together to form one
connexon it is called a heteromeric connection.
• when two identical connexons come together to form
a gap junction channel it is called homotypicgap
junction channel.
• when a connexons comes in contact with a similar
channels form and adjoining cell it forms a gap
junction providing communication between cytoplasm
of the two cells

13. Diagram

14. Diagram

15. The end