Smooth muscle contraction is regulated by the cycling of myosin II between on and off states.

     OR

Smooth muscle contraction is regulated by myosin regulatory light chain associated with the myosin II neck domain.

TLS Online TPP Program

#Id: 1355

#Unit 4. Cell Communication and Cell Signaling

MEK, a dual-specificity protein kinase

TLS Online TPP Program

#Id: 9032

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 9033

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 9034

#Unit 4. Cell Communication and Cell Signaling

Ligand binding depends on: 

Multiple weak, noncovalent forces

Molecular complementarity

TLS Online TPP Program

#Id: 9035

#Unit 4. Cell Communication and Cell Signaling

Binding of the ligand to the receptor causes the receptor to change from an inactive conformation (R) to an active conformation (R*). Only the active R* conformation of the receptor can trigger the signal transduction pathway.

TLS Online TPP Program

#Id: 9036

#Unit 4. Cell Communication and Cell Signaling

The affinity of a signal molecule’s binding to its receptor is quantified by the dissociation constant for binding (Kd).