What role do phosphatases play in signal transduction pathways?

They inactivate protein kinases to turn off signal transduction.

They activate protein kinases by phosphorylation.

They transfer a phosphate group from one protein in the pathway to the next molecule in the series.

They amplify the second messenger cAMP.

Ans.

The phosphatases are enzyme molecules that remove phosphate groups from their substrates. In signal transduction pathways, phosphatases deactivate protein kinases by breakdown of phosphoric acid mono esters into free hydroxyl group and a phosphate ion. It causes termination of signal transduction as protein kinases are no longer active to transmit signals.

Thus, the correct answer is 'they inactivate protein kinases to turn off signal transduction.'