TraB, a novel plant ER-mitochondrial contact site protein functions as a mitophagy receptor in plants.

Autophagic degradation of mitochondria (known as mitophagy) is known to occur in all eukaryotes, and is important for the turnover of damaged mitochondria and recycling of nutrients during starvation. Targeting of mitochondria for autophagic degradation is regulated by recognition of mitochondrial-localized mitophagy receptors by the autophagy adaptor protein, ATG8, which regulates the formation of phagophore membranes to encapsulate mitochondrial cargo. Mitophagy receptor proteins have been well characterized in animals and yeast; however, proteins that function as mitophagy receptors in plants have not been discovered until now. We have recently characterized the plant TraB-family proteins AT1G05270/TRB1 and AT2G32340/TRB2, as novel mitophagy receptors, elucidating novel mechanisms of mitophagy in plants.