adhesion molecules Flashcards
name the main adhesion molecules
cadherins
integrins
Ig superfamily
selectins
Claudins
occludins
What is the structure and role of cadherins?
they are Ca dependent glycoproteins with an extracellular domain and linked intracellularly to actin filaments via catenins
role is to Mediate homophilic binding in adherens junctions and desmosomes, maintaining tissue integrity.
Which adhesion molecules mediate cell-ECM interactions?
integrins via heterodimeric α and β subunits binding to ECM proteins like fibronectin and laminin.
What is the role of selectins?
Mediate transient cell-cell adhesion during processes like leukocyte rolling in inflammation
What are tight junction proteins, and their function?
Claudins and occludins; they form barriers regulating paracellular transport in epithelial tissues
How do focal adhesions function?
Anchor cells to ECM, transmit mechanical forces, and serve as signaling hubs via integrins
What cytoskeletal components link to cadherins and integrins?
Cadherins: Actin filaments via catenins.
Integrins: Actin (focal adhesions) or intermediate filaments (hemidesmosomes)
Name an example of an adhesion structure that provides mechanical strength
Desmosomes, using desmogleins and desmocollins linked to intermediate filaments
What is the difference between homophilic and heterophilic adhesion?
homophobic between same molecules
heterophilic between different molecules
give an example of homophobic adhesion
cadherins
give an example of heterophilic adhesion
integrins to ECM proteins
How do tight junctions function as barriers?
restrict solute and ion passage
Which adhesion molecules play a role in immune cell adhesion?
Ig superfamily
ICAMs VCAMs
What happens when E-cadherin is lost in cancer cells?
loss of adhesion leads to increase in metastasis
What junction type regulates paracellular transport?
Tight junctions, through claudins and occludins.
