The AAUAAA is needed for cleavage and polyadenylation because deletion or mutation of the AAUAAA hexamer prevents generation of the polyadenylated 3’ end

TLS Online TPP Program

#Id: 9328

#Unit 4. Cell Communication and Cell Signaling

Arrestin binds tightly to rhodopsin only when rhodopsin kinase has phosphorylated a sufficient number of C-terminal serines and threonines.

TLS Online TPP Program

#Id: 9329

#Unit 4. Cell Communication and Cell Signaling

The entire process of rhodopsin phosphorylation and its inactivation by arrestin is fast completed within 50ms. 

TLS Online TPP Program

#Id: 9330

#Unit 4. Cell Communication and Cell Signaling

Phosphorylated rhodopsin is restored to its light-sensitive state (R) during dark adaptation by a specific rhodopsin phosphatase

TLS Online TPP Program

#Id: 9331

#Unit 4. Cell Communication and Cell Signaling

In the dark, most transducin is localized to the outer segment, while most arrestin is found in other parts of the cell; in this condition, vision is most sensitive to very low light levels.

TLS Online TPP Program

#Id: 9332

#Unit 4. Cell Communication and Cell Signaling

In bright light, little transducin is found in the outer segment, and abundant arrestin is found there; in this condition,vision is relatively insensitive to small changes in light.

TLS Online TPP Program

#Id: 9333

#Unit 4. Cell Communication and Cell Signaling

An evolutionarily conserved family of receptor serine kinases - TGF-β receptor family