Dr. Zhang’s group have a long-term interest in understanding the role of protein modification in the mechanism of diseases. Particularly, they are interested in arginylation, which is a posttranslational addition of one extra arginine to the protein. Arginylation usually leads to the rapid degradation of the target protein. It may also change the structure/function of the protein by changing the surface charge. Based on sequence-based prediction, at least 20% of any given proteome is expected to affected by arginylation. Arginylation is an emerging topic studied by less than 20 total in the world.
Arginylation in mammalian cells is mediated by a single enzyme, arginyltransferase1 (Ate1). Ate1 is conserved from yeast to human, with an evolutionary root potentially from in alpha-proteobacteria, the ancestor of mitochondria. They are studying the role of Ate1-mediated arginylation from a very broad perspective.