An Arabidopsis Rab18 GTPase promotes autophagy by tethering ATG18a to the ER in response to nutrient starvation

This study finds that ATG18a acts as a downstream effector of RABC1, a member of the poorly characterized Rab18/RabC GTPase subclass in plants. Active RABC1 interacts with ATG18a on the ER, particularly under nutrient starvation. In rabc1 mutants, autophagy is compromised, especially under nutrient deprivation, affecting the ER association and expansion of ATG18a-positive autophagosomes. Furthermore, both dominant-negative and constitutively active RABC1 forms inhibit autophagy. The dominant inactive RABC1 impedes the ER association of ATG18a, whereas the constitutively active RABC1 delays ATG18a detachment from the ER. Collectively, RABC1 regulates the ER association and the subsequent detachment of ATG18a-positive autophagosomes during nutrient starvation.PMID:38056450 | DOI:10.1016/j.devcel.2023.11.006

Source: Developmental Cell - December 6, 2023 Category: Cytology Authors: Jiaqi Sun Yang Shao Songyang Wang Xunzheng Li Shuqing Feng Weina Wang Pierre Leroy Chengyang Li Huanquan Zheng Source Type: research