Final answer:
One general translation unit inactivated by phosphorylation is the protein serine/threonine phosphatase. Phosphorylation can lead to the inactivation of certain proteins, and it plays a significant role in various cellular processes including the cell's response to stress and energy metabolism.
Step-by-step explanation:
Phosphorylation and Its Effects on Proteins
Phosphorylation is a critical post-translational modification that can regulate the activity of proteins within the cell. It involves the addition of a phosphate group, typically to the serine, threonine, or tyrosine residues of proteins, which can lead to changes in the protein's function. The transfer of the phosphate group is typically catalyzed by an enzyme known as a kinase. Conversely, the removal of the phosphate group, known as dephosphorylation, is catalyzed by phosphatases. Protein serine/threonine phosphatases, which remove phosphate groups from serine or threonine amino acids, play an important role in regulating cellular processes and can deactivate certain proteins when they are phosphorylated.
For instance, phosphorylation has been implicated in the response of plants to aluminum stress, with certain kinases and phosphatases being differentially regulated in this condition. In some cases, the phosphorylation of a protein can inactivate it, as is suggested in the relationship between serine/threonine kinases and protein phosphatases in apoptotic pathways. Similarly, the phosphoenolpyruvate (PEP)-dependent phosphotransferase system (PTS) is affected by phosphorylation, impacting the availability of glucose and lactose transport within the cell.