Enzymes that catalyze the removal of phosphate groups from phosphorylated proteins are called: Phosphotransferases.
Kinases.
Phosphatases.
Dephosphatases.
Pyrophosphatases.
The correct answer and explanation is:
Correct Answer: Phosphatases
Phosphatases are enzymes that catalyze the removal of phosphate groups from molecules, particularly from phosphorylated proteins. This process is known as dephosphorylation. Phosphorylation and dephosphorylation are essential biochemical modifications that regulate protein function, activity, location, and interaction with other molecules.
In many cellular pathways, kinases first add phosphate groups to proteins, a process called phosphorylation. This typically occurs on amino acids like serine, threonine, or tyrosine. The addition of a phosphate group can activate or inactivate the protein or alter its interaction with other molecules. To reverse this process, phosphatases remove the phosphate group, returning the protein to its original state or modifying its function further.
Phosphatases are classified based on the type of amino acid residue they target. For example, protein tyrosine phosphatases remove phosphate groups from tyrosine residues, while serine/threonine phosphatases act on serine or threonine residues. These enzymes play a critical role in regulating signal transduction pathways such as those involved in cell growth, division, and apoptosis.
Disruption in the balance between kinase and phosphatase activity can lead to various diseases, including cancer, diabetes, and neurodegenerative disorders. Overactive kinases or underactive phosphatases may result in prolonged signaling that drives abnormal cell behavior.
Unlike kinases, which require ATP to transfer phosphate groups, phosphatases use hydrolysis to cleave the phosphate bond, releasing inorganic phosphate. This makes phosphatases essential counter-regulators of kinase-mediated phosphorylation.
The other options are incorrect:
- Phosphotransferases transfer phosphate groups but do not remove them.
- Kinases add phosphate groups.
- Dephosphatases is not a standard scientific term.
- Pyrophosphatases hydrolyze pyrophosphate but are not involved in protein dephosphorylation.
Therefore, phosphatases are the correct enzymes responsible for removing phosphate groups from proteins.