Best Ppt For Students

1. PRESENTED
BY
SAJAD ALVI
L1F19BSBT0063
ABDUL REHMAN
DAR
L1F19BSBT0048

2. CELL SIGNALING
 INTRODUCTION:
o regulate virtually all aspects of cell behavior
- cell proliferation, Metabolism, Organellar and cell movement.

3. MODES OF CELL SIGNALING
 Direct cell-cell signaling
 Signaling by secreted molecules
 Signaling molecules

4. WHY DO CELL COMMUNICATE?
Here are few reasons;
 Regulation
 Environmental stimuli
 Maintenance
 Control

5. INTRACELLULAR SIGNALING
 The transfer of information from one cell to another cell.
 Important for cell to grow, and work normally.
 Take place between the cell in the extracellular matrix.

6. TYPES OF INTERCELLULAR
SIGNALING PATHWAY:
 Autocrine signaling
 Paracrine signaling
 Endocrine signaling
 Juxtacrine signaling

7. Receptors
 Receptors are proteins
associated with cell
membrane or located within
the cell.
 Recognize Signaling
 Changes Cell Behavior

8.  An agent which activates receptor
 Inverse Agonist : Activate receptor
to produce effect in opposite direction
to that of agonist.
 Antagonist: Prevents the action of
an agonist.
 Partial Agonist: Activate receptor to
produce submaximal effect.
Agonist

10.  To propagate regulatory signals
 To amplify the signal
 To integrate various extracellular
and intracellular regulatory signal
 To adapt changes and maintain
homeostasis
 To facilitate gene expression
Function of Receptors

11. G protein-coupled Receptor
• also known as seven-(pass)-transmembrane domain receptors
• constitute a large protein family of receptors that
detect molecules outside the cell and activate internal signal
transduction pathways and, ultimately, cellular responses
• G protein-coupled receptors are found only in eukaryotes,
including yeast, choanoflagellates and animals

13. Structure & Function

14. Kinase-linked Receptors
 A kinase-linked receptor (KLR) is a transmembrane receptor, which uses second
messenger signaling that triggers a cascade of cellular events.
 Ligands bind to the receptor-binding site at the extracellular domain, which
causes phosphorylation of amino acids, mainly tyrosine, within the intracellular
domain.
 Phosphorylation initiates the signaling cascade which leads to gene transcription
and changes in expression of target genes resulting in altered cell function.

15. Types of KLR
1. Receptor tyrosine kinase or
RTKs
2. Receptor serine/threonine
kinases (RSTK)
3. Receptor guanylyl cyclases

16. Structure &Function

17.  It is commonly known as ionotropic receptors, are a group of
transmembrane ion channel proteins which open to allow ions such
as Na+, k+, Ca²+ and Cl¯ to pass through membrane in response to
the binding of a chemical messenger such as a neurotransmitter.
 When a presynaptic neuron is excited, it releases neurotransmitter
from vesicles into the synaptic cleft.
 The neurotransmitter then binds to receptors located on the
postsynaptic neuron. If these receptors are ligand - gated ion
channels, a resulting conformational change opens the ion channels,
which leads to a flow of ions across the cell membrane
Ligand-Gated Ion Channels

18.  This, in turn, results in either a
depolarization, for an
excitatory receptor response, or
hyperpolarization, for an
inhibitory response

19. These proteins are typically
composed of at least two different
domains: a transmembrane
domain which includes the ion
pore, and an extracellular domain
which includes the ligand binding
location.
Structure of Ligand