Team:Hong Kong HKUST/Project/module3

Overview

In vertebrates, the signal sequence coding region promotes translocation of precursor peptide. In our project, we introduced bacterial enzymes to mammalian cell to modify metabolic pathway. However, unlike bacteria, citric acid cycle in mammalian cells is compartmentalized in mitochondria. The glyoxylate enzymes (AceA and AceB proteins, denoted ACE enzymes) should be targeted to mitochondria for their functionality. To do so, we fused ACE enzymes with Mitochondrial Leader Sequence (MLS). We have constructed and qualitatively and quantitatively characterized Mitochondrial Leader Sequence BioBrick BBa_K1119001.

Mechanism of MLS

MLS is attached to the N-terminal of the protein in interest. The MLS will be recognized by receptor on outer mitochondrial membrane. The complex of receptor and attached protein will diffuse to contact site, where the outer and inner membrane come into contact. The protein will be translocated across mitochondrial membrane via a protein translocator. Preprotein is unfolded and bind to the TOM complex on mitochondrial outer membrane, then it will pass to TIM complex on inner membrane side. Mitochondrial chaperone will be involved in pulling preprotein into mitochondria and refold the protein.