presynaptic active zone membrane obsolete integral component of presynaptic active zone membrane https://github.com/geneontology/go-ontology/issues/23424 true This term was obsoleted because it represents protein topology, not a cellular component. cellular_component GO:0099059 OBSOLETE. The component of the presynaptic active zone membrane consisting of the gene products and protein complexes having at least some part of their peptide sequence embedded in the hydrophobic region of the membrane.