Final answer:
The statement that GTPases dephosphorylate phospho-tyrosine is false because this function is carried out by phosphatases. GTPases are involved in the hydrolysis of GTP to GDP.
Step-by-step explanation:
The answer to the student's question is false. GTPases do not dephosphorylate phospho-tyrosine; this function is performed by enzymes called phosphatases. GTPases, on the other hand, are involved in hydrolyzing GTP (guanosine triphosphate) to GDP (guanosine diphosphate), thus playing an important role in signaling pathways, but not directly in dephosphorylation processes.
Phosphatases, such as Protein Tyrosine Phosphatases (PTPs), are the enzymes responsible for the removal of phosphate groups from phosphorylated amino acid residues, including phospho-tyrosine. Phosphorylation and dephosphorylation of proteins, including those involving tyrosine residues, can have various effects on the cell, such as altering DNA replication, cell division, pathogen recognition, RNA stability, and post-translational modifications, highlighting the critical role these processes play in cell signaling and regulation.