Subdomains of the endoplasmic reticulum (ER) known as omegasomes (because of their omega shape in fluorescence microscopy), which are characterized by the protein DFCP1, have been proposed to promote shaping of phagophores,
Now, researcher Viola Nähse and her co-workers in Harald Stenmark´s group, in collaboration with associate professor Kay Schink, have shown that DFCP1 is an ATPase that constricts omegasomes and in this way promotes autophagosome formation. Its activity is particularly important for the formation of large autophagosomes involved in selective autophagy of large cytoplasmic objects such as damaged mitochondria and protein aggregates.
Selective autophagy plays crucial roles in preventing both cancer development and neurodegenerative diseases, and the current findings are therefore particularly interesting in this context.