Chapter 15, Problem 12P

Summary Introduction

To discuss:  The properties of two types of organization of kinases (held in a signaling complex by a scaffolding protein and the other kinases are freely diffusible) in terms of signal amplification, speed, and potential for cross-talk between signaling pathways.

Introduction:

In cell signaling pathways, the signaling proteins act as molecular switches. These are activated (ON) or deactivated (OFF) by phopshorylation/ dephosphorylation. The protein kinases add phosphate groups to amino acid residues on signaling proteins and protein phosphatases remove phosphate groups. These works in signaling cascade, that is, one activated kinase relays the signal and phosphorylate the next kinases.