Chaperone-assisted membrane protein folding: YidC/Oxa1/Alb3 is a membrane protein family that plays a critical role in folding and assembly of membrane proteins in the inner membranes of bacteria, mitochondria, and chloroplasts. In E. coli, YidC forms a membrane insertion pore independent of SecYEG complex, major protein translocation machinery. YidC also has a chaperone activity: it facilitates the folding of a variety of SecYEG-dependent proteins. To understand how YidC acts as chaperone, we will tackle three specific problems:

•    What are the driving forces in YidC-substrate interaction?
•    What mechanism does YidC use to facilitate folding of membrane proteins?
•    How are the structure and dynamics of YidC related to the function?

Controlled degradation of membrane proteins: Rapid protein degradation is a crucial cellular process that enables the clearance of misfolded proteins and regulatory proteins that are no longer needed. In all cells, this process is mediated by AAA⁺-protease superfamily. FtsH is the only membrane-localized AAA⁺-protease, which degrades both membrane and cytosolic proteins. To understand the principles of the quality control mechanism of membrane proteins, the lab focuses on three specific questions using FtsH from E. coli as model.

•    What sequence or structural features of substrates are subject to degradation?
•    What is the role of the FtsH transmembrane domain in recognition and translocation of substrates?
•    How is the proteolytic activity modulated by other membrane-bound cofactors?

*See web link below for figure images.

Source: https://www.chemistry.msu.edu/faculty-research/faculty-members/hong-heedeok.aspx