The Chang lab has used genetic and biochemical approaches to study cellular mechanisms to maintain quality control at various organellar sites in the budding yeast Saccharomyces cerevisiae.  Mechanisms to recognize and send misfolded proteins for degradation are found at multiple cellular locations, including the endoplasmic reticulum, Golgi and plasma membrane.  These mechanisms are critical for cell health as misfolded proteins are often associated with disease.  More recently, we have been analyzing how organellar interactions, in particular between mitochondria and endoplasmic reticulum, are necessary to maintain homeostasis of each individual compartment, as well as relieving environmental stress.