It's our great honor to invite Dr Fangliang Zhang from the University of Pennsylvania School of Veterinary to give a PSF series talk on "How is the nucleotide coding sequence related to a posttranslational modification?". During the talk Dr. Zhang will also share with us his experience on looking for a tenure track position in the US.
Speaker: Fangliang Zhang, PhD, University of Pennsylvania School of Veterinary
Time: April 27 Wednesday 6:00-7:30pm
Venue: Clinical Research Building (CRB) room 302
Abstract: Actin is the major component of microfilament cytoskeleton. Nonmuscle cells contact two actin isoform beta and gamma actin, which are extremely similar in amino acids. Beta-actin is found to have N-terminal arginylation, which regulates its function. However gamma-actin was never found to be arginylated on the same site in vivo. To investigate this puzzle, we check the metabolic fate of artificially arginylated gamma-actin and found it is highly unstable and selectively ubiquitinated and degraded in vivo compared to the beta-actin. This instability was regulated by the differences in the nucleotide coding sequence between the two actin isoforms, which conferred different translation rates. Gamma-actin was translated more slowly than Beta-actin, and this slower processing resulted in the exposure of a normally hidden lysine residue for ubiquitination, leading to the preferential degradation of gamma-actin upon arginylation. This is the first demonstration that the nucleotide coding sequence can be utilized to regulate protein posttranslational state.
