Potassium restriction boosts vacuolar acidity and extends lifespan in yeast.

Lysosome function is compromised during aging and in many disease states. Interventions that promote lysosomal activity and acidification are thus of prime interest as treatments for longevity and health. Intracellular pH can be controlled by the exchange of protons for inorganic ions, and in cells from microbes to man, when potassium is restricted in the growth medium, the cytoplasm becomes acidified.

Mutations in the chromodomain-like insertion of translation elongation factor 3 compromise protein synthesis through reduced ATPase activity.

Translation elongation is mediated by ribosomes and multiple soluble factors, many of which are conserved across bacteria and eukaryotes. During elongation, eukaryotic elongation factor 1A (eEF1A; EF-Tu in bacteria) delivers aminoacylated-tRNA to the A-site of the ribosome, whereas eEF2 (EF-G in bacteria) translocates the ribosome along the mRNA. Fungal translation elongation is striking in its absolute requirement for a third factor, the ATPase eEF3.

The many roles of the eukaryotic elongation factor 1 complex.

The vast majority of proteins are believed to have one specific function. Throughout the course of evolution, however, some proteins have acquired additional functions to meet the demands of a complex cellular milieu. In some cases, changes in RNA or protein processing allow the cell to make the most of what is already encoded in the genome to produce slightly different forms.

Eukaryotic polyribosome profile analysis.

Protein synthesis is a complex cellular process that is regulated at many levels. For example, global translation can be inhibited at the initiation phase or the elongation phase by a variety of cellular stresses such as amino acid starvation or growth factor withdrawal. Alternatively, translation of individual mRNAs can be regulated by mRNA localization or the presence of cognate microRNAs.