Final answer:
GFP is attached to proteins through the genetic fusion of the GFP gene with the gene of the protein of interest, resulting in a combined polypeptide allowing for tracking of the protein.
Step-by-step explanation:
GFP, or Green Fluorescent Protein, is attached to proteins to serve as a label for tracking their dynamic activities by genetically fusing the GFP gene to the gene of the protein of interest. During the translation process in the cell, this fusion leads to the production of a single polypeptide chain that includes both the GFP and the target protein. The tagRFP fluorescent reporter can be advantageous because it retains its fluorescence in acidic environments, which is useful for proteins that localize to cell compartments like the plant cell wall. For instance, the At5g11420::tagRFP protein construct in N. benthamiana leaf epidermal cells generates a red fluorescent signal that can co-localize with specific cell wall markers, thus facilitating the study of protein localization even under various conditions such as plasmolysis induced by substances like glycerol or CaCl2.