The document discusses cell adhesion molecules which are glycoproteins located on cell surfaces that mediate cell-cell binding. There are five major classes of cell adhesion molecules: cadherins, immunoglobulin superfamily CAMs, selectins, integrins, and mucins. Cadherins are calcium-dependent and mediate homophilic binding between identical cells through intracellular signal transmission. Integrins are heterodimers that bind cells to the extracellular matrix and transmit outside-in and inside-out signals. Selectins mediate transient interactions between cells through calcium-dependent binding of their extracellular domains to sugar moieties on other cells.

1. CRANIOFACIAL BIOLOGY, CELL ADHESION
MOLECUES AND MECHANISM OF ADHESION

2. DEVELOPMENT OF FACE:
• The development of face begins by the 4th week of intrauterine life.
• Stomatodeum- separating the future brain and pericardium.
• Buccopharyngeal membrane – separated the future oral cavity and the gut.

3. • Neck is formed by the elongation of regions between the Stomatodeum and
pericardium.
• 6 pharyngeal arches and 5 pharyngeal pouches

6. DEVELOPMENT OF THE EXTERNAL FACE:

7. DEVELOPMENT OF THE PALATE:

8. DEVELOPMENT OF THE TONGUE:

9. • The connection between the cell or the contact between the cell and the extracellular
matrix is called cell junction.
• also called membrane junction.
• Classified into :
- Occluding junction
- Communicating junction
- Anchoring junction
DEFINITION & CLASSIFICATION:
CELL ADHESION MOLECUES AND MECHANISM OF ADHESION

11. • Cell adhesion molecules are glycoproteins that is located on the cell surface.
• These proteins are typically trans-membrane receptors and are composed of three domain:
- intracellular domain
- transmembrane domain
- extracellular domain
CELL ADHESION MOLECLES:

12. • Homophilic binding: If the cell adhesion molecules between two neighboring cells are
the identical. (Cadherin-Cadherin)
• Hetrophilic binding: If the cell adhesion molecules between two neighboring cell are
not identical. (Selectin-Mucin)
TYPES OF CELL ADHESION MOLECULES BINDING:

13. CLASSIFICATION OF CELL ADHESION MOLECULES (CAMs):
Cell adhesion molecules (CAMs) belong to five major protein families :
• Cadherin
• Ig super family CAMs
• Selectins
• Integrin
• Mucins

14. • Large family of glycoprotein
• Calcium dependent adhesion
• It transmit signal from extracellular membrane to cytoplasm
• Homophilic interaction
TYPES:
• 30 types of cadherin are known
1. E= epithelial
2. P= placental
3. N=neural
4. R= retinal
Brain express largest number of cadherin
CADHERINS:
• Role of cadherin
• Signal transmission to cytoplasm
• Tissue morphogenesis
• In cell differentiation

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

16. • 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 to inside)
INTEGRIN:

17. • 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

18. • Family of integral membrane glycoprotein
• Binds 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
SELECTIN:

19. Types :
1) E selectin
2) P selectin
3) L selectin
Role:
• Attachment of mammalian embryos to
the wall of uterus during implantation
• Selectin mediate transient interaction
between circulating leukocytes and vessel
wall at site of inflammation and clotting

20. • The Mucins are the group of serine and threonine-rich protein and hydroxyproline
enabling post-translational O-glycosylation.
• Their extended structure allows them to present sulfated carbohydrate moieties as
binding site for selectins
MUCIN: