The Pat1-Lsm Complex Stabilizes ATG mRNA during Nitrogen Starvation-Induced Autophagy

Gatica, D., et al. The Pat1-Lsm Complex Stabilizes ATG mRNA during Nitrogen Starvation-Induced Autophagy. Molecular Cell. 6/12/2018.

Macroautophagy/autophagy is a key catabolic recycling pathway that requires fine-tuned regulation to prevent pathologies and preserve homeostasis. Here, we report a new post-transcriptional pathway regulating autophagy involving the Pat1-Lsm (Lsm1 to Lsm7) mRNA-binding complex. Under nitrogenstarvation conditions, Pat1-Lsm binds a specific subset of autophagy-related (ATG) transcripts and prevents their 30 to 50 degradation by the exosome complex, leading to ATG mRNA stabilization and accumulation. This process is regulated through Pat1 dephosphorylation, is necessary for the efficient expression of specific Atg proteins, and is required for robust autophagy induction during nitrogen starvation. To the best of our knowledge, this work presents the first example of ATG transcript regulation via 30 binding factors and exosomal degradation.