The ARLA1A-NAC089 module coordinates ER-phagy with the unfolded protein response (UPR) to maintain cellular homeostasis in plant

The accumulation of misfolded or unfolded proteins triggers ER stress, which can be alleviated through the unfolded protein response (UPR) and ER-phagy. These processes work in concert to preserve ER homeostasis, yet the molecular interactions between them remain poorly understood in plant.

In this study, we identify the ER-anchored transcription factor NAC089 as an ER-phagy receptor acting downstream of the ADP-ribosylation factor (ARF)-like (ARL) GTPase ARLA1A under carbon starvation. Furthermore, we demonstrate that active ARLA1A inhibits ER-phagy by negatively regulating NAC089. Notably, the ARLA1A-NAC089 axis coordinates ER-phagy with the UPR to balance cell survival and death.