Answer: There are three roles of RNA in protein. The messenger RNA carries the message of DNA from the nucleus to the cytoplasm. This message is used by the ribosomes to make proteins. Transfer RNA is a small RNA molecule that participates in protein synthesis. Ribosomal ribonucleic acid is the RNA component of ribosomes, the molecular machines that catalyze protein synthesis. These are the three functions of the three types of RNA protein synthesis.