This Presentation Deals With What Is A Cell Signalling, The Components, Its Stages, Main Events Involved, Autocrine Signalling, Paracrine Signalling, Endocrine Signalling And The References Respectively.

1. TYPES OF CELL
SIGNALLING
Submitted By,
LOGESWARAN KA
P20BIT1013
I-MSC.BIOTECHNOLOGY
PERIYAR UNIVERSITY.

2. Contents
• What Is Cell Signalling?
• Components of Cell Signalling
• Stages of Cell Signalling
• General Events Of Signalling
• Types of Cell Signalling
1. Autocrine Signalling
2. Paracrine Signalling
3. Endocrine Signalling
• References

3. What Is Cell Signalling?
• Fundamental Process Of All Organisms.
• Cell Signalling – Initiation Of Biological
Response In The Target Cell Results From
The Release And Interaction of Chemical
Compounds Called Signalling Molecules
Produced By The Host Cell.
• Very Important For Critical Cell Decisions.
Signalling
Ligands + Receptors  Response
(Host Cell) (Target cell) (On Target
Cell)

4. Components Of Cell Signalling
• Host Cell - The Cell Producing Ligands.
• Ligands - Contains Information
Responsible For The Response - Produced
By The Host Cell.
• Receptors - Surface Proteins Of Target
Cell - Ligands Binding Site - Key proteins
Mediates The Cell Signalling Events.
• Intracellular Messengers - Secondary
Messengers - Intermediate Compounds
Carries The Cell Signal To The Intracellular
Sensors.
• Target Cell - The Receipient Cell And
Where The Biological Response Will Be

5. Stages Of Cell Signalling
• Reception - Detection Of Ligands By The
Target Cell When Ligands Binds To
Receptors Present On The Surface.
• Transduction - Signal Cascade Process
(Series Of Reactions) - Activated After The
Completion Of Reception – Production Of
Final Molecule (Has Ability For Triggering
Biological Response) As A End Product.
• Response - Initiation Of Biological
Response By The Final Molecule On The
Target Cell.

6. General Events Of
Signalling
• The Common Steps For All Types Of Cell
Signalling Includes,
1) Production And Release Of Ligands By The
Host Cell.
2) Travel Of Ligands To The Receptors Site.
3) Binding Of Ligands To The Receptors.
4) Production Of Ligand-Receptor Complex.
5) Signal Cascade Events (Series Of
Reactions).
6) Production Of Final Signalling Molecule
After Signal Cascade Events.
7) Initiation Of Biological Response On The
Target Cell.

7. Types Of Cell Signalling
• There Are 3 Types Of Cell Signalling
Events.
1) Autocrine Signalling
2) Paracrine Signalling
3) Endocrine Signalling

8. 1) Autocrine Signalling
• Definition – Release Of Ligands By A Host
Cell And Then Binding Of Ligands To The
Receptors Of Same Cell To Initiate Biological
Response.
• Host And Target Cell Is Same.
Biological Roles
• The Early Development Of Organisms. i.e.
Cells And Tissue Function.
• Regulation Of Pain Sensation.
• Regulation Of Inflammatory Response.
• Apoptosis During Viral Infections.
• Regulation Of Embryo Development.

9. 2) Paracrine Signalling
• Definition - Release Of Ligands By A
Host Cell And Then Binding Of Ligands
To The Receptors Of Nearby Target
Cells.
• Localized Chemical Responses And The
Chemical Signal Duration Is Short.
• Movement Of Paracrine Signals To
Nearby Cells Is Performed By Diffusion
Through Extracellular Matrix (ECM).
• Example - Synaptic Signalling Where
Neurotransmitters Transfered Between
Nerve Cells As Electric Impulses.

10. Biological Roles
• Localized Cell Activities With Nearby
Cells.
• Maximization Of Cellular Response
Fidelity In Wound Signalling.
• Mammary Gland Development And
Function.
• Study Of Various Types Of Cancers
And Intratumoral Heterogeneity.

11. 3) Endocrine Signalling
• Definition - Release Of Ligands By A
Host Cell And Binding Of Ligands To The
Receptors Of Distant Cells To Initiate
Biological Response.
• Endocrine Signals Transmitted Over
Long Distances Through The
Bloodstream.
• Endocrine Signals Are Produced By
Endocrine Glands And The Ligands Are
Called As Hormones. Eg. Thyroid
Glands.
• Slower Response Due To Travel Via

12. Biological Roles
• Metabolic Activities.
• Control And Coordination Of Biological
Activities Throughout The Body.
• Cell Growth And Development.
• Reproduction And Sexual
Characteristics.
• Maintenance Of Sugars, Salts And
Body Fluid Levels.

14. Overview Of Synaptic Signalling

15. References
1. Alberts.B, Molecular Biology Of The Cell,
Garland Science Taylor&Francis Group, 5th
Edition, Pg 882.
2. Karp, Cell And Molecular Biology, Concepts
And Experiments, Wiley Publications, 8th
Edition, Pg 583.
3. https://bio.libretexts.org/Bookshelves/Introducto
ry_and_General_Biology/Book%3A_General_B
iology_(Boundless)/9%3A_Cell_Communicatio
n/9.1%3A_Signaling_Molecules_and_Cellular_
Receptors/9.1B%3A_Forms_of_Signaling
4. https://www.khanacademy.org/science/biology/c
ell-signaling/mechanisms-of-cell-
signaling/a/introduction-to-cell-
signaling?modal=1

16. THANKS FOR WATCHING…