Golgi apparatus lifecycle

The Golgi apparatus is built and maintained by membrane traffic: COPII vesicles bring proteins and lipids from the ER, cisternae mature as COPI vesicles return ER residents and recycle Golgi enzymes, the cisternae glycosylate and sort their cargo, and carriers leave the trans-Golgi network for the plasma membrane and endosomes. In animal cells the Golgi also disassembles at mitosis and reassembles in the daughter cells. This umbrella module composes the modules for those stages by reference. COPI coat assembly is required in every eukaryote; ER export by COPII is optional because the only COPII module is written for Drosophila.

Organelle lifecycle umbrella (see projects/ORGANELLE_LIFECYCLES.md); stage roles follow the shared skeleton. Read as a satisfiability rule, the umbrella is satisfied when COPI coat assembly is. COPII is optional because a eukaryote-wide COPII rule cannot yet be grounded locally: human SEC24A, SEC31A and PREB (Sec12) have no entry in the local PANTHER tables, and the SAR1 and SEC23 families have no PAINT table. Not yet modelled, because no eukaryote-wide module exists: the Golgi tethers (golgins, TRAPP, COG), the Golgi SNAREs, glycosylation in the cisternae, trans-Golgi network exit by clathrin and AP-1, and mitotic Golgi disassembly and reassembly, which is not universal.