Recombinant Saccharomyces cerevisiae Vacuolar aminopeptidase 1 (LAP4)

Resident vacuolar enzyme that catalyzes the removal of amino acids from the N-terminus of peptides and proteins. Also acts as the major cargo protein of the cytoplasm-to-vacuole targeting (Cvt) pathway. The precursor form of aminopeptidase 1 (prApe1) assembles into dodecamers and the propeptide mediates the aggregation of dodecamers into higher multimers. The multimers are then recognized via the propeptide by their receptor ATG19, and ATG19 further interacts with ATG11, which tethers the APE1-ATG19 complex to the pre-autophagosomal structure (PAS). The cargo-receptor complex (also Cvt complex) is selectively enwrapped by a double-membrane structure termed the Cvt vesicle under vegetative growth conditions and by a similar but larger double-membrane structure termed the autophagosome under nitrogen starvation conditions. The Cvt vesicle or the autophagosome fuses with the vacuolar membrane and release its content in the vacuolar lumen. In the vacuole, prApe1 is processed into mature aminopeptidase 1 (mApe1).