text: In 1986, the N-end rule was elucidated, and it states that the identity of the amino acid at the N-terminus of the protein's amino acid sequence determines the half-life of the protein. In an effort to determine the effects of arginylation on the half-life of proteins, several studies were performed using modified yeast proteins. These studies revealed that when proteins were engineered to include N-termini which had been arginylated, the modified proteins were metabolically unstable. Furthermore, it was also discovered that protein ubiquitination and degradation become more likely to occur when a protein is arginylated. The evidence gathered from these experiments make it clear that arginylation in vivo leads to the degradation of proteins with asparagine and glutamine residues at their N-termini. 
  However, there have also been several recent studies which have shown that protein degradation may not be the prevalent function of arginylation, but that this modification may also be important for certain proteins to function correctly. For instance, when arginylation occurs on beta amyloid proteins, the proteins are guided into their proper alpha helical shape and are also prevented from misfolding and aggregating. Another protein which benefits from arginylation is calreticulin because when modified, its role during endoplasmic reticulum stress is facilitated, rather than it being removed from cells entirely. As both degradation and facilitation effects of arginylation have been identified and studied, it is clear that arginylation has an important role in protein regulation within cells.