Cell signaling involves communication between cells through signaling molecules. There are four types of cell signaling: autocrine, paracrine, endocrine, and juxtacrine. Signaling molecules can be non-polar or polar. There are three main types of cell surface receptors: G protein-coupled receptors, tyrosine kinase receptors, and ion channel receptors. G protein-coupled receptors activate intracellular signaling pathways through G proteins. Tyrosine kinase receptors dimerize and phosphorylate upon ligand binding to activate intracellular signaling. Ion channel receptors open or close ion channels to change the cell's membrane potential.

1. CELL SIGNALING
1

2. Presented By:-
Arnab Banerjee
UID:- TNU2019043100010
Programme:- BSc (H) Biotechnology
Batch:- 2019 -2022 , Semester:- 6th,year:- 3rd
2

3. What is Cell signaling
Types of cell signaling
Nature of signaling molecule
Types of receptor
G Protein coupled receptor
Tyrosine Kinase receptor
Ion channel receptor
Conclusion
Reference
Acknowledgement
3

4. WHAT IS CELL SIGNALING ?
Cell signaling is about communication between
different groups of cells and tissues, how one group of
cells informs another group of cells what to do.
4

5. TYPES OF CELL SIGNALING
Cell signal are 4 types :-
1. Autocrine signal
2. Paracrine signal
3. Endocrine signal
4. Juxtracrine signal
5

6. AUTOCRINE SIGNAL:-
Cell itself release signal molecule and this signal bind on own cell
receptor and initiate signal transduction .
Example:- Immune cells :-
T Lymphocytes release interleukin -2
And this interleukin 2 bind the same T -
Lymphocytes and start cell proliferation
6

7. PARACRINE SIGNAL:-
When signal molecule release from a cell and bind to the another cell
(neighbour cell ). That called Paracrine signal.
Example:-
1. Neurotransmitter
2. Blood clotting factor etc.
7

8. ENDOCRINE SIGNAL:-
When cell release Signal molecule transfer to blood and target to
another cells which are become activate. This signal is long distance
signalling.
Example:- Pancreas :-
α cell release glucagon
β c ell release insulin
8

9. JUXTRACRINE SIGNAL:-
In this the cell have physical contact with each other without
different type of signalling molecule called juxtracrine signal.
Example :- immune cell
9

10. NATURE OF SIGNALING MOLECULE:-
Two type of signalling molecule :- 1.Non polar ,2. polar
Non polar polar
Hydrophobic signal Hydrophilic signal
Can cross plasma membrane Can not to cross plasma membrane
10

11. TYPES OF RECEPTOR:-
Receptor are 2 types:-
1. Intracellular receptor
2. Cell surface receptor
Intracellular receptor Cell surface receptor
Located in the cytosol or
nucleus
Located in the plasma membrane
Ex:- Nuclear family receptor Ex:- G protein coupled receptor, Ion
channel receptor, enzyme linked
receptor .
11

12. CELL SURFACE RECEPTOR:-
1. G protein coupled receptor ( GPCR):- It is the type of polar signalling
molecule. Here G means Guanine Nucleotide binding protein.
Structure of GPCR:- This is GPCR have two domain
Exoplasmic site another is Cytosolic site .
G protein coupled complex composed of
3 subunit that is Gα subunit, β subunit, γ subunit.
When Gα subunit associated with GDP then it
Inactive from. And When Gα subunit associated with GTP then it active
from.
12

13. ACTIVATION OF G PROTEIN:-
Signal (like glucagon, epinephrine) come and bind to the GPCR receptor
Then GDP dissociated from Gα subunit and bind GTP
and Gα subunit activated and Gα subunit dissociated from
beta and gama subunit.
This Gα subunit bind to the enzyme( like adenylyl cyclase)
and Produce CAMP by the help of ATP.
When GTPase is come and hydrolase the GTP and convert
GDP then Gα subunit bind to beta and gama subunit and
Convert into inactive from.
13

14. CLASSIFICATION OF G(ALPHA)
SUBUNIT :-
4 types of subunit :- 1. Gs subunit, 2.Gαi subunit,3.Gαq subunit,4. Gαt subunit.
1. Gs subunit:- it activation of Adenylyl cyclase
2. Gαi subunit:- Inhibits adenylyl cyclase
3. Gαq :- activation of phospholipase C-β
4. Gαt :- activation of Rhodopsin cell and stimulate of Phosphodiesterase
14

15. ENZYME LINKED
RECEPTOR:-
1. Tyrosine kinase receptor:-
Structure:- This receptor composed
of one monomeric subunit but when
ligand is bind the receptor then the
monomeric subunit from into dimeric
from.
15

16. Stimulate of cell growth or proliferation
Metabolic regulation
Inhibition of Apoptosis
Signals of Tyrosine Kinase Receptor:-
1.Stimulate of cell growth or proliferation:-
EGF:- Epidermal Growth Factor
FNG:- Fibroblast Growth Factor
NGF:- Nerve Growth Factor
PDGF:- Platelet Derived Growth Factor
2. Metabolic regulation:-
Insulin 16

17. ACTIVATION OF RECEPTOR TYROSINE
KINASE:-
Signal come and bind to the two monomeric subunit of the receptor tyrosine kinase
The conformational change of monomeric subunit and come close each other and from dimeric subunit
and it active
When dimeric subunit are from two kinase domain become in close proximet with each other
It result one subunit first phosphorylate then phosphorylated tyrosine residues of other subunit is
called trans phosphorylate.
17

18. ION CHANNEL RECEPTOR:-
Ion channel other names ionotropic receptor .
Example of ion channel linked receptor is Acetylcholine receptor
Function:- Synaptic signalling between electrically cells
Ligand:- Acetylcholine
1. Ligand Gated Ion Channel:- Na+ and k+ Pumps
Resting Potential :- Membrane potential of resting neuron when the neuron is not any receving any
impuse is the resting potential.
Depolarization:- During the stimulate the Na+ voltage gated channel open and Na+ influx occurs.
Repolarization:- K+ channel will be open after depolarization .this leads to efflux of K+ and
repolarization
Hyperpolarization:- Due to the delay of K+ channel the K+ efflux will be more and hyperpolarization
of occur.
18

19. OTHER TYPE OF
RECEPTOR:-
1. Serin-Threonine kinase receptor
2. Frizzeld receptor
3. Patched receptor
4. TNF family receptor
19

20. CONCLUSION:-
Lastly we conclude that Cells typically receive signals
in chemical form via various signaling molecules. When
a signaling molecule joins with an appropriate receptor
on a cell surface, and cell is active and do metabolic
work.
20

21. ACKNOWLEDGMENT:-
I would like to express my thanks of gratitude to our Payal
Paul mam and as well as the department of biotechnology of
The Neotia University who gave the golden opportunity to do
this wonderful presentation on the topic of: Cell Signaling .
I also thankful to my friend who helps me the complete
this presentation within a time period.
I am very thankful of them
21

22.  https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.britannica.com%2Fscience%2FG-
protein-coupled-
receptor&psig=AOvVaw1dcX2ynhuaVL9hcZsgZNhw&ust=1652195941234000&source=images&c
d=vfe&ved=2ahUKEwidqdfS29L3AhUF_TgGHS4aBe4Qr4kDegUIARDWAQ
 https://www.google.com/url?sa=i&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FReceptor_t
yrosine_kinase&psig=AOvVaw3IxCnZSJWRMFJbbJ2G4v-
e&ust=1652196003687000&source=images&cd=vfe&ved=2ahUKEwj9l7vw29L3AhUi4XMBHQsT
CtMQr4kDegUIARDJAQ
 https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.jbc.org%2Farticle%2FS0021-
9258(20)76746-
3%2Ffulltext&psig=AOvVaw21EJnuwlyaM7fcibq2FDpJ&ust=1652196041348000&source=image
s&cd=vfe&ved=2ahUKEwj557WC3NL3AhUi4XMBHQsTCtMQr4kDegUIARDoAQ
22

23. 23