In interphase nuclei, this underlying proteinaceous structure changes its organization to occupy the entire nucleus; during interphase the structure is referred to as the matrix rather than the scaffold.

TLS Online TPP Program

#Id: 6539

#Unit 7. System Physiology – Animal

The insulin receptor is a combination of four subunits held together by disulfide linkages: 

Two alpha subunits 

Two beta subunits

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#Id: 6540

#Unit 7. System Physiology – Animal

The binding of insulin is communicated through the single TM helix of each beta subunit to the paired Tyr kinase domains inside the cell, activating them to phosphorylate each other on three Tyr residues (Tyr1158, Tyr1162, Tyr1163)

TLS Online TPP Program

#Id: 6541

#Unit 7. System Physiology – Animal

TLS Online TPP Program

#Id: 6542

#Unit 7. System Physiology – Animal

Fat and muscle cells express large amounts of the insulin-responsive glucose transporter GLUT4

TLS Online TPP Program

#Id: 6543

#Unit 7. System Physiology – Animal

In resting cells, virtually all of the GLUT4 is localized to small vesicles in the cytosol While some GLUT4 is in endosomes, most is in a unique small organelle termed the GLUT4 storage vesicle (GSV)

TLS Online TPP Program

#Id: 6544

#Unit 7. System Physiology – Animal

In GSV, much of the GLUT4 is tethered to the Golgi matrix, a network of coiled-coil proteins surrounding the Golgi complex,  by a TUG protein