Cell Signaling

VI. CELL SIGNALING

• Autocrine Signaling

VI. CELL SIGNALING, cont• Coordinates cell activities, development• Typically involves 3 steps:

Reception – Target cell’s detection of signal molecule due to binding of signal molecule to receptor protein in cell membrane

Transduction – Binding of signaling molecule changes receptor protein; triggers a sequence of events within cell

Response – Results in specific cellular response; for example, activation of genes, enzyme catalysis, etc.

VI. CELL SIGNALING, cont

• Reception Typically involves G Proteins

VI. CELL SIGNALING, cont• Transduction

Typically multi-step pathway Relay molecules are usually protein kinases

VI. CELL SIGNALING, cont

• Transduction Non-protein

molecule known as cAMP is often second messenger

VI. CELL SIGNALING, cont• Response

Nuclear May “turn on” or “turn off” genes

CytoplasmicMay regulate enzyme activity

ApoptosisControlled cell suicide

VI. CELL SIGNALING, cont

• Regulation