Rongmin Zhao

Teaching Interests

• BIOC12H: Biochemistry I: Proteins and Enzymes
• BIOD12H: Protein homeostasis
• CSB1020H LEC121: Protein homeostasis in regulating plant development and stress response

Research Interests

Research Area: Plant Biology, Protein Biochemistry, Cell and Molecular Biology

Keywords:

• Plant cell and molecular biology
• Plant organelle protein homeostasis
• Yeast model and genetics
• Protein folding and degradation
• Protein-protein interactions
• Protein trafficking within the cell and organelles
• Abiotic stress and response

Current Research

Protein homeostasis in plant organelles-Unlike prokaryotes, eukaryotic cells contain membrane bounded organelles; each performs some unique functions. The biogenesis and function of organelles are coordinated and tightly regulated by developmental and environmental cues so as to achieve their essential functions. Because of the membrane barrier, organelles like plastid, mitochondrion and endoplasmic reticulum (ER) have their own independent protein quality control (PQC) systems inside to ensure protein folding, trafficking, function and turnover in a timely manner. Compromised PQC in plant organelles often causes malfunction and impaired biogenesis of the organelles. Our lab is interested in understanding the mechanisms underlying protein homeostasis in plant organelles, with a focus on the role of heat shock protein HSP90 family members within plant ER and chloroplast.

The mechanism of selective protein degradation by the proteasome - The ubiquitin-proteasome system within the cell selectively degrades proteins. The substrate selectivity is controlled primarily by the polyubiquitination pathway. However, under extreme and certain special growth conditions, the proteasome can degrade proteins in unconventional ways depending on the stressors and the metabolic states of the cell. Our group identified that the proteasome regulatory particle contains regions that can bind and trigger certain protein degradation independent of the polyubiquitination pathway, particularly when the cellular metabolic status is changed. We are interested in further understanding molecular mechanisms of ubiquitin-independent protein degradation and use both baking yeast and plant Arabidopsis as models to study the complex cellular protein degradation processes.