One mechanism by which the activity of the replication origin is controlled is DNA methylation. 

TLS Online TPP Program

#Id: 10089

#Unit 4. Cell Communication and Cell Signaling

Integrins are involved in biological activities, includes: 

Extravasation

Cell-to-cell adhesion

Cell migration

Receptors for certain viruses

Angiogenesis

Apoptosis

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#Id: 10090

#Unit 4. Cell Communication and Cell Signaling

Integrins can mediate outside-in and inside-out signaling

TLS Online TPP Program

#Id: 10091

#Unit 4. Cell Communication and Cell Signaling

Outside-in signaling

Binding of integrins to their ligands induces conformational changes in their cytoplasmic domains, directly or indirectly altering their interactions with cytoplasmic proteins

TLS Online TPP Program

#Id: 10092

#Unit 4. Cell Communication and Cell Signaling

Inside-out signaling

intracellular signaling pathways can, via adapter proteins, modify the ability of integrins to bind

to their extracellular ligands

TLS Online TPP Program

#Id: 10093

#Unit 4. Cell Communication and Cell Signaling

Integrin exist in two conformations: 

Inactive, low-affinity, “bent” conformation  

Active, high-affinity, “extended” conformation

TLS Online TPP Program

#Id: 10094

#Unit 4. Cell Communication and Cell Signaling

Activation of integrins involves:

Conformational changes near the propeller and 

 βA domains

Separation of the transmembrane and cytoplasmic domains