If this ratio R is equal to 1, then the population is randomly dispersed.

If R is significantly greater than 1, the population is evenly dispersed

If R is significantly less than 1, the population is clumped

TLS Online TPP Program

#Id: 9613

#XL - T Zoology

In the absence of insulin, the extracellular domain adopts a symmetric inverted U-shaped conformation. 

TLS Online TPP Program

#Id: 9614

#XL - T Zoology

Upon insulin binding, the extracellular domain is converted into a T-shaped conformation that brings the transmembrane domains together.

TLS Online TPP Program

#Id: 9615

#XL - T Zoology

Four related EGF receptors participate in signaling by the many members of EGF family :

In the mouse - Erb-B1, 2, 3, and 4

In humans - HER 1, 2, 3, and 4

TLS Online TPP Program

#Id: 9616

#XL - T Zoology

Homodimerization

HER1 directly binds EGF which leads to formation of a homodimer of the HER1 extracellular domain

TLS Online TPP Program

#Id: 9617

#XL - T Zoology

TLS Online TPP Program

#Id: 9618

#XL - T Zoology

Neuregulins 1, 2, 3, and 4, bind to HER4 that, like HER1, can also form homodimers.