Cell adhesion molecules are proteins located on cell surfaces that bind cells together and to the extracellular matrix. They can be classified into families including cadherins, integrins, immunoglobulin superfamily CAMs, and selectins. CAMs help mediate processes like tissue development, wound healing, and immune cell migration through homophilic or heterophilic binding of extracellular domains.

1. CELLADHESIONMOLECULES
SUBMITTED BY:
PAKEEZA NAQVI
G1F17BSZL0053

2. “Celladhesionmolecules(CAMs)areasubsetofcelladhesionproteinslocatedon
thecellsurfaceinvolvedinbindingwithothercellsorwiththeextracellularmatrix
(ECM)intheprocesscalledcelladhesion.Inessence,celladhesionmoleculeshelp
cellssticktoeachotherandtotheirsurroundings.”
DEFINITION

3. INTRODUCTION
o Cell adhesion molecules mediate, through their
extracellular domains, adhesive interactions between
cells of the same type (homotypic adhesion) or
between cells of different types (heterotypic adhesion).
o A CAM on one cell can directly bind to the same kind
of CAM on an adjacent cell (homophilic binding) or to a
different class of CAM or ECM (heterophilic binding).
o Cell-cell adhesions can be tight and long lasting or
relatively weak and transient.

4. CAM’s
o CAMs are proteins located on the cell surface
involved in binding with other cells or with the
ECM in the process called cell adhesion.
o Can be classified into four families
 CADHERINS
 INTEGRINS
 IMMUNOGLOBULIN SUPERFAMILY(IgSF)
 SELECTINS

6. CAM’sdomain
Cams are typically transmembrane receptors And are composed
of three domains:
INTRACELLULAR DOMAIN- interacts with
cytoskeleton and intracellular signaling
molecules.
TRANSMEMBRANE DOMAIN
EXTRACELLULAR DOMAIN- interacts with
other CAMs or ECM.

8. CAMplayrole
in:
 Cell-cell interactions.
• Embryogenesis.
• Immunity(migration of immune cells to the inflamation
center).
• Cell-tissue-organ development.
• wound healing.
• Cancer metastasis.

9. Cadherin
The primary CAMs in adherens junctions and
desmosomes belong to the cadherin family.
The role of cadherins is not limited to mechanical
adhesion between cells. Rather, cadherin function
extends to multiple aspects of:
 tissue morphogenesis,including cell recognition and
sorting,
 boundary formation and maintenance
 coordinated cell movements and the induction
 maintenance of structural and functional cell and
tissue polarity.

10. CONTI…
 Cadherins have been implicated in the formation and
maintenance of diverse tissues and organs ranging from
polarization of simple epithelia to mechanically linking
hair cells in the cochlea to providing an adhesion code for
neural circuit formation during wiring of the brain.
 The diversity of cadherins arises from the presence of
multiple cadherin genes and alternative RNA splicing.

12. DEVELOPMENT
ALROLESOF
CADHERINS
E-cadherin is the first cadherin expressed during
mammalian development. It helps to cause compaction,
an important morphological change that occurs at the
eight-cell stage of embryo development.
• Differential expression of cadherins (either by
modulating subtype or expression level) induces sorting
out of mixed cell populations.
• Cadherin subtype switching occurs during coordinated
cell movements such as neurulation,where the
invaginating neural plate expresses N-cadherin, while
the overlying ectoderm expresses E-cadherin.

14. INTEGRINS
 Integrins are a large family of type I
transmembrane heterodimeric glycoprotein
receptors that function as the major metazoan
receptors for cell adhesion and connect the
intracellular and extracellular environments.
 Integrins can bind to extracellular matrix (ECM)
glycoproteins including collagens, fibronectins,
laminins,and cellular receptors such as vascular cell
adhesion molecule-1 (VCAM-1) and the intercellular
cell adhesion molecule (ICAM) family.

15. CONTI…
• Integrins also play key roles in the assembly of the
actin cytoskeleton as well as in modulating signal
transduction pathways that control biological and
cellular functions including cell adhesion, migration,
proliferation, cell differentiation,and apoptosis.

16. ROLEOFFEW
IMPORTANT
INTEGRINS

17. ROLEOF
INTEGRINS
 Attachment of cell to ECM
 Signal transduction from ECM to cell have
relation to-
-cell growth
-cell division
-cell survival
-cellular differentiation
-apoptosis
-cell migration during embryogenesis ,
thrombosis, haemostasis,wound healing etc.

18. IMMUNOGLOBUL
INSUPERFAMILY
CAM
(IgSF-CAM)
IgSF cell adhesion molecules are calcium-independent
transmembrane glycoproteins.
 Each IgSF CAM has an extracellular domain, which
contains several Ig- like intra-chain disulfide-bonded
loops with conserved cysteine residues, a
transmembrane domain, and an intracellular domain
that interacts with the cytoskeleton.
 They are either homophilic or heterophilic and bind
integrins or different IgSF CAMs.

20. SELECTINS
 Selectins are a unique family of 3 adhesion molecules
that are expressed and function only on cells in the
vasculature.
 The term selectin was originally proposed to highlight
the presence of the lectin domain, as well as to
emphasize the selective nature of the expression and
function of these molecules.
 Selectins mediate the first step required for emigration
of leukocytes from the bloodstream, tethering of a
leukocyte in flow.

21. Typesof selectin
 E-selectin (in endothelial cells)
 L-selectin (in leukocytes)
 P-selectin (in platelets and endothelial cells)

22. Conclusion
 Cell adhesion and adhesion molecules have been shown to
contribute to the pathogenesis of a large number of
common human disorders and tumor cell metastasis in
cancer.
 Recent studies have demostrated that CAM are involved
in signal transduction pathways.
 These molecules transmit signals from the extracellular
matrix to the cell interior (outside-in) and from the inside
of the cell to the outside (inside-out) similar to those
transduced by growth factors, hormones and cytokines.
 These results are extremely significant in metastatic
spread and the treatment of a large number of human
disorders.