Tomoki Chiba

In our body, proteins are in a dynamic state; the speeds of protein synthesis and degradation are tightly regulated. Protein degradation is individually regulated by the ubiquitin–proteasome system, which plays critical roles in many biological systems such as embryogenesis, the immune system, and memory.

The major goal of our laboratory is to gain an understanding of:

  1. The components and regulation of intracellular protein degradation at a molecular level.
  2. The physiological roles of selective protein degradation in our bodies.

The ubiquitin system
Ubiquitin is a small protein that acts as a degradation signal. Ubiquitin attaches to its substrate by a cascade reaction catalyzed by enzymes, namely E1, E2s and E3s.
(Keywords: Cullin, NEDD8, signalosome)

Proteasome activators
Proteasome is a barrel-shaped multisubunit protease complex that captures and degrades ubiquitinated proteins. The activity of the proteasome is regulated by multiple proteasome activators.
(Keywords: Ecm29, proteasome, PA28, PA200)

My lab is focusing on:

  1. The regulation and role of Cullin-RING ubiquitin ligase complexes in protein degradation.
  2. The role of proteasome activators in protein degradation, by using multiple knockout mice.