Question

What are the 2 major activities performed by integrins? How are integrins activated?

Answer 1

Answer:

Integrins are transmembrane integeral membrane protein receptors composed of heterodimers with α and β subunits. Major activities performed by integrins are:

1) Adhension to substrate: Integrins play a active role in the attachment of the cells to the extracellular matrix (ECM)

2) Signal transduction: Integrins are involved in signal transduction from the extracellular matrix to the cell and cell migration. Integrins also regulate platelet aggregation process at the wound site

Integrin activation involves following steps:

• Intracellular signals act on the integrin cytoplasmic domains
• This induces conformational changes in the integrin extracellular domain.
• As a result, the affinity of the integrin receptors for ligand binding increases.
• The ligands that activate integrin are: chemokines in leukocytes, thrombin in platelets