Leucine aminopeptidase LyLAP enables lysosomal degradation of membrane proteins.

ABSTRACT: Breakdown of every transmembrane protein trafficked to lysosomes requires proteolysis of their hydrophobic helical transmembrane domains. Combining lysosomal proteomics with functional genomic datasets, we identified lysosomal leucine aminopeptidase (LyLAP; formerly phospholipase B domain-containing 1) as the hydrolase most tightly associated with elevated endocytosis. Untargeted metabolomics and biochemical reconstitution demonstrated that LyLAP is a processive monoaminopeptidase with preference for amino-terminal leucine. This activity was necessary and sufficient for the breakdown of hydrophobic transmembrane domains. LyLAP was up-regulated in pancreatic ductal adenocarcinoma (PDA), which relies on macropinocytosis for nutrient uptake. In PDA cells, LyLAP ablation led to the buildup of

SUBMITTER: Jain A 

PROVIDER: S-EPMC12832182 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature