Phosphatases

Definition

Phosphatases are enzymes that remove phosphate groups from proteins or other molecules, a process known as dephosphorylation. They play a critical role in regulating cellular activities by reversing the actions of kinases.

5 Must Know Facts For Your Next Test

1. Phosphatases counteract the activity of kinases by removing phosphate groups from target proteins.
2. These enzymes are crucial in turning off signal transduction pathways once a signal has been received and processed.
3. There are two main classes: protein tyrosine phosphatases (PTPs) and serine/threonine phosphatases, each specific to different amino acids.
4. Phosphatase activity is essential for maintaining cellular homeostasis and controlling cell cycle progression.
5. Mutations or dysregulation of phosphatases are often associated with diseases such as cancer and diabetes.

Review Questions

• What is the primary function of phosphatases in cellular signaling?
• How do phosphatases interact with kinases within signal transduction pathways?
• Name two main classes of phosphatases and indicate their specificity towards amino acids.

Related terms

Kinase: Enzymes that add phosphate groups to proteins or other molecules, typically activating them.

Signal Transduction Pathway: A series of molecular events and chemical reactions that lead to a cellular response after the reception of an external signal.

Dephosphorylation:

The removal of a phosphate group from an organic compound by the action of phosphatases.