different type of adhesion molecules which play important role in cell function as well as structure. main importance in cell to cell interaction.

1. CELL ADHESION
MOLECULES
MITAL CHANDEGARA
BT PREVIOUS

2. Content
 Brief Introduction
 Cell adhesion molecules
 Selectin
 Cadherin
 Ig like CAM
 Integrin

3. CELL - CELL INTERACTION
• Varying degree of interaction found in body
• 2 types:- Stable ( in tissue)
Transient ( in immune response)
IMPORTANCE
• Bidirectional transfer of information between exterior and interior
of cell
• Development and functioning of multicellular organism
• In tissue formation

4. Interaction between CAM

5. Types
4 types of cell adhesion molecules
1) Selectin
2)Cadherins
3)Ig like cell adhesion molecules
4)Integrin

7. Selectin
• Family of integral membrane glycoprotein
• Which bind with particular arrangement of sugar which project
from surface of other cell
• Calcium dependent adhesion
STRUCTURE
• Small cytoplasmic domain
• Membrane spanning domain
• Large extracellular domain ,in which outer most domain act as
lectin

8. Types
1) E selectin
2) P selectin
3) L selectin

9. Role
• Attachment of mammalian embryos to the wall of uterus
during implantation
• Selectin mediate transient interaction between circulating
leukocytes and vessels wall at site of inflammation and
clotting

10. Cadherin
• Large family of glycoprotein
• Calcium dependent adhesion
• It transmit signal from extracellular membrane to cytoplasm
• Homophilic interaction
Types
• 30 types of cadherins are known
1. E= epithelial
2. P= placental
3. N=neural
4. R= retinal
Brain express largest number of cadherins

11. Structure
• Integral membrane glycoprotein which made up from 720-750
amino acids
• Large extracellular segment which have 5 or 6 domain which have
same size and structure
• Single transmembrane domain
• Small cytosolic domain which attached with catenin family of
cytosolic protein
Role of catenin
• Tether the cadherin to cytoskeleton
• Signal transmission to cytoplasm

12. “Velcro like formation “
Key role
• in cell differentiation
• tissue morphogenesis

13. Cadherin Activation

14. Ig like CAM
• It consist polypeptide chain which composed of number of
similar domain
• Each domain contain 70-110 amino acids which organised into
tightly folded structure
• It present on wide variety of protein called “immunoglobin
superfamily”
• Members of Ig superfamily are involve in immune function
• It mediate calcium independent cell - cell interaction
• Weak adhesion & homophilic & heterophilic interaction

16. Example
1. NCAM = Neural cell adhesion molecule (CD56)
chromosome 11 , expressed on surface of neurons and skeletal
muscles . It also detect on Tc cell and dendritic cell
2. VCAM =Vascular cell adhesion molecules (CD106)
chromosome 1 , mediate adhesion of lymphocytes , monocytes ,
eosinophils , basophils to vascular endothelium
3. L1 cell adhesion molecule
Role: nervous system development ,neuronal migration and
differentiation

17. Importance of L1 in Human
• L1 syndrome is an inherited, X linked disorder occurring in male
that primarily affect the nervous system
• Mainly characterized by hydrocephalus, muscles stiffness &
difficulty in speaking
• It is generally observed in 1 in 30000 males

18. Integrin
• Calcium dependent adhesion
• Large family of integral membrane proteins which found only in
animals
• Large class of cell surface receptors
• Two major types of activities:
1. adhesion of cells to their substratum
2. transmission of signals from the external environment to the
cells interior ( outside –in)

19. Structure
• Heterodimer of alpha and beta subunit and they are non
covalently linked with each other
• In mammals ,29 integrin are known
1. 18 alpha subunit
2. 8 beta subunit
• Different combination of these alpha and beta subunit form
all 29 integrin molecules

20. • Two subunit are oriented to
form Globular extracellular
head & Pair of elongated legs
• The legs of each subunit
extend through membrane as
a single transmembrane helix
• End in small cytoplasmic
domain of about 20-70 amino
acids

21. • Beta 2 integrin mainly mediate cell – cell interaction , it bind
with specific ligand on another cell such as endothelial cell
sometimes it may be Ig superfamily.
• It enable WBC to attach firmly to endothelial cell at site of
infection & migrate out of the blood stream to the infected site
• human with genetic disease called leucocytes deficiency are
unable to synthesized beta 2 subunit
• Their WBC lack the beta 2 receptor & suffer with repeated
bacterial infection

22. Bibliography
Cell Biology - Channarayappa
Cell and Molecular Biology - Gerald Karp
Webliography
 https://www.ncbi.nlm.nih.gov/books/NBK9851/

23. Thank you