Hidden Enzymes in Proteins: Secret Signalers in Cells

Scientists have found tiny, active enzymes, called guanylate cyclases (GCs) and adenylate cyclases (ACs), hidden inside bigger proteins in both simple and complex life forms. These enzymes can do jobs like helping cells talk to each other or detect changes in their environment. For instance, in the phytosulfokine receptor (PSKR), these enzymes help control how the protein works within a cell. In plants like Arabidopsis thaliana, a protein called AtKUP5 has both AC and phosphodiesterase (PDE) activities, which can sense and regulate potassium flow and hormone responses. Researchers are now looking for more of these hidden enzymes by searching for specific patterns in proteins. This method might help us find old, hidden functions in different living things, like how cells sense hormones or gases.