This document is a certificate and report for a seminar presented by Dharti Baleshwar Bandarwar on the topic of "Cell Communication & Cell Signaling". The seminar was guided by Dr. Swati Kaushik and submitted in partial fulfillment of a Master's degree in Zoology from Rashtrasant Tukdogi Maharaj Nagpur University. The report defines cell communication and signaling, describes the types and components of signaling pathways, and discusses the significance of cell signaling and its role in disease.

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INSTITUTE OF SCIENCE, NAGPUR [RTMN
UNIVERSITY] (2021-2022)
SEMINAR TOPIC :- CELL COMUNICATION & CELL SIGNALING
MSC 1ST YR.
DEPARTMENT OF ZOOLOGY
PREENTED BY,
DHARTI BALESHWAR BANDARWAR
GUIDED BY :- DR. SWATI KAUSHIK
CERTIFICATE
This is to certify that, miss. Dharti Baleshwar
Bandarwar M.Sc. – Sem III (Zoology) has prepare and
submitted her seminar report on Topic :- “CELL
COMMUNICATION & CELL SIGNALING” under the supervision
of Dr. SWATI KAUSHIK associate professor, as per curriculum
of Rashtrasant Tukdogi Maharaj Nagpur University for the
award of degree of master of science in zoology.
Seminar guide-
Dr. Swati Kaushik
Aso. Prof.
Dept. of zoology
Dr. Anjali M. Rahatgaonkar
Head of department
zoology

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AKNOWLEDGEMENT
I wish to express my deep regards to Dr. Anjali M.
Rahatgaonkar, Director of Institute of science, Nagpur for providing
the facilities for our studies.
I am heartly thankful to Dr. Archana Nerkar, Head Department
of zoology, for her constant encouragement and support for the
seminar.
I wish to give my sincere thanks to Dr. Swati Kaushik for her
guidance and co-operation during the preparation of the seminar
topic.
Lastly, I thank the person who helped me in directing the
information mentioned in this project. I am really thankful to all my
professor and friends for the valuable co-operation, moral support
and constant encouragement during preparation of my seminar.
Miss. Dharti B. Bandarwar
M.Sc. Sem III (Zoology)

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Contents
• Introduction (Cell communication)
• Types of communication
• Sell signaling (definition)
• Introduction
• Classification
• Properties of cell signaling
• Phases of cell signaling
• Cell signaling component
• Classification of cell signaling
• Significance of cell signaling
• Diseases and cell signaling
• Future of cell signaling
• References

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Cell communication
Introduction
• Cell communication is most important for the
multicellular organism for the normal activity in a daily
life.
• Cell communication occurs by electrochemical
communications.
• All the communication system involve receive,
collection, and responding to appropriate information
according to the cell signaling molecules (Internal or
External communication)
• Cellular Response depends upon the signaling molecule
and cell type.

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Types of communication
• Internal communication mainly involves the nervous
and endocrine system, these are important for he
homeostasis an regulation of the vital body function.
• It is he communication which generates inside the body
and self regulate.
• Signaling molecules:- neurotransmitters and Hormones
Internal signaling
molecules
External signaling
molecules
Which are already present
in the body
We take comes from
external environment
Hormones Any drugs or Medicine
Neuro transmitter
Local hormones
ions
All are internal signaling
molecules which helps in
regulation of body
function
These work like an internal
molecules
Molecule- receptor- cellular
response

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External communication we get message or information
from environment like test, smell, sound, and optic
vision which are the part of external communication,
nervous system also plays the important role on it,
Example – Eye
• Eye gets optic signals (message)
• Message transmitted to the
brain through neuron
• On the basis of message brain get activated
• Then interrupted on the system
to convert vision to visualization
effect, what was Infront of us,
• we capture it. ( i.e. laptop, mobile..)

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Cell signaling
Definitions
Signaling :-
Is the fundamental process by which specific information
is transfer from the cell surface to the cytosol and ultimately
to the nucleus.
Signal transduction:-
It is the process by which a cell responds to substances
outside the cell through signaling molecules found on the
surface of and inside the cell, it is important for cell to grow
and work normally.
Legend:-
Any molecule or matter that binds irreversibly to a receiving
protein molecules (receptors)
Receptors:-
A cell or group of cells that receives stimulae, binds to
specific ligan. Transmit signals to intracellular targets.
Different receptors can respond differently to the same
ligand.

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Introduction
Cell signaling :-
A biological mechanism that occurs in cells which
gives cell an ability to receive or generate the signals in
response to their surrounding environment.
Diagram explain:- The signaling molecules which are binds to any
receptor present on cell surface or cytosol after binding they get
activated to the cell signaling pathway and produce responds inside
the cells.
Cell signaling depends on three factor,
• Signaling molecule
• Signaling transduction pathway
• Cell type

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Signal transduction:-
A signal- transduction pathway is series of step by which a
signal on a cell’s surface or nucleus is converted into a
specific cellular response within the cell.
Cellular responses:- depending upon signaling molecule, cell
type and signaling pathway
Classification
Intracellular:-
In most cases a chain of reaction transmitted signals
from the cell surface to a variety of intracellular targets- a
process called intracellular signal transduction… intracellular

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signaling pathways thus connect to cell surface to the
nucleus, leading to changes in gene expression in response to
extracellular stimuli.
Intercellular :-
& it I communication between cells… the major method
of intercellular communication employs messenger
substances (Hormones) that are secreted by signal-
producing cells and registered by target cells. All cells
produce and receive multiple, diverse signal.
Properties of cell signaling
Specificity:-
Cell specificity results from the existence in any cell
type from the existence in any cell type of a unique set of
protein and there isoform at each level of signal transduction
cascades.
Affinity:-
It shows affinity between legend and the binding site
on the receptor.
Cooperativity:-
It is a type of behavior where a number of seemingly
independent component of a system act collectively in

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unison or near a unison. But cooperativity is also important in
cell-cell signaling transduction regulation and more complex
processes governing of cells.
Sensitization:-
It is an important property that they sensitize,[ is their
excitability can be increase]
Amplification:-
A major advantage of such a chemical signaling
schemes is signal amplification.. amplification occurs because
individual signaling reaction can produce a large number of
products.
Integration:-
They are intimately liked at multiple levels by signal
transduction.
Phases of cell signaling
According to Arl w Sutherland there are three phases [ basic
phases]
Signal recognition:-
Ligand binding; cell contact

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Signal transduction:-
• Transfer of signal to cell interior
• Modulate the activity of protein kinase and
phosphatases
Response:-
• Phosphorylate on state of targets
• Modulation of effector activity
• Reversibility of response
Cell signaling component
Signaling molecules
1. Hormones
2. Neurotransmitter
3. Cytokines

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Chemical classes
1. Amino acid
2. Lipid
3. Phospholipid
4. Monoamines
5. Proteins
6. Glycolipids
Signaling receptors
1. Ligand gated ion channel [LGIC]- fastest
2. G-protein coupled receptor [GPCR]
3. Enzyme linked receptor
4. Nuclear tyrosine kinase- slowest
5. Receptor tyrosine kinase
6. Adhesion receptor
7. Steroid receptor

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Intracellular signaling pathway activated by
extracellular signaling molecules
Signaling
molecules
Target
proteins
Intracellular
signaling
pathway
Responses
Acetylcholine LGIC
[Nm recep.]
Na+
conduction Skeletal muscle
contraction
Acetylcholine GPCR
[M2-
recep.]
(-)cAMP/ PK-A
pathway
Inhibition of
cardiac activity
Adrenaline GPCR
[Beta-
1recep]
(+)cAMP/ PK-A
pathway
Increase the
cardiac activity
Non-
adrenaline
GPCR
[Alfa-
1recep]
(+)Ip3/ca2+
pathway
Vasoconstriction
Growth
factor
Tyrosine
kinase
linked
receptor
(+)Ras/Raf/MAPL Protein synthesis
for growth
Nitric oxide Cytoplastic
guanylyl
cyclase
enzyme
(+) Cgmp
pathway
vasodilation
Secondary messenger

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• Secondary messenger are intracellular signaling
molecules released by the cell in response to exposure
to extracellular signaling molecules.
• Secondary messengers are small molecules and ions
that relay singles received by cell surface receptors to
effector proteins… these messengers then diffuse
rapidly from the source and bind to target proteins to
alter their properties (activity, localization, stability ,etc.)
to propagate signaling.
Examples:- cyclic AMP, cyclic GMP, inositol triphosphate,
diacylglycerol, and calcium.
Classification of signaling pathway
Autocrine:-
Autocrine signaling is a form of cell signaling in which a cell
secretes a hormones or chemical messenger ( autocrine
agent) that binds to autocrine receptor on that same cell,
leading to change in a cell .
Ex:- the monocyte produce cytokines that effect
themselves.

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Paracrine:- [local action]
Paracrine signaling is a form of signaling a type of cellular
communication in which a cell produces a signal to induce
change In nearby cell (adjacent cell)
Ex:- response of histamine, serotonin and prostaglandins
Endocrine:- [long distance action]
• Cell hormones travels through a blood to the responding
cell
• In which a hormones are chemical controlled by your
endocrine glands that helps coordinate and control
many of our body activity.
• In vertebrates, the hypothalamus is the neural control
center for all endocrine system.
Ex:- Response of endocrine hormones

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Juxtracrine:-
Juxtracrine signaling is a type of cell-cell or cell
extracellular matrix signaling in multicellular organisms that
required close contact.
[Difference between [pracrine & juxtracrine]
The key differnce btween paracrine and juxtracrine is
that, the pracrine signaling requires the releas of signaling
molecules into externacellular space and the diffusion of
them in the space. While juxtracrine signaling requires
requires close contact of cell, cells use these chemical signal
to communicate.

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Synaptic:-
One unique example of paracrine signaling is synaptic
signaling, in which nerve cells transmission signals this
process is named for synapse, the junction between two
nerve cell where signal transmissin occurs.
Neurotransmission is released from vesicles at the end
of the axon of the sending cell.
Significance of cell signaling
➢ Cell signaling is basis of prokaryote and eukaryote life
➢ For normal function coordination of every signaling
pathway is necessary
➢ Altered signaling pathway may lead to diseases
➢ Defect can be in any component of signaling ultimately
leading to the disease development
➢ Cell signaling has been identified in cancer,
cardiovascular disease, Alzheimer’s disease and many
other disorders
➢ Cell signaling- an important area of research for drug
discovery

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Diseases and cell signaling
▪ Cancer
▪ Alzheimer’s diseases
▪ Diabetes
▪ Epilepsy
▪ Heart disease
▪ Hypertension
▪ Metabolic syndrome
Future of cell signaling
• With advances in separation methodology, mass
spectrometry, and hybridization, complex protein
interaction in cellular signaling networks should become
clear.
• Future cell signaling studies would involve integration of
genomic ,transcriptomic, proteomic and metabolomic,
data that will provide complete picture of cellular
mechanisms and their responses.
References
The cell – Albert
Life science – Pranav Kumar/ Usha Mina
Cell- Lewis
Biochemistry- Lehniger