FEATURES

FAMILY

DESCRIPTION

Also known as AMPL_YEAST, APE1, API, LAP4, YSC1. 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). Homododecamer. The precursor form of aminopeptidase 1 (prApe1) assembles into dodecamers and further aggregates into higher multimers (the Ape1 complex) in the cytoplasm. The Ape1 complex is disaggregated in the vacuolar lumen, but mature aminopeptidase 1 (mApe1) retains its dodecameric form. Dodecamer assembly in the cytoplasm is essential for formation of an enzymatically active complex. If cytoplasmic homododecamerization of prApe1 is disturbed in mutants, homododecamers of mApe1 will form in the vacuole, but they are enzymatically inactive. Interacts with ATG19.

EXTERNAL LINKS

APE1

Vacuolar aminopeptidase 1

APE1

Molecular Synopsis