Editing Golgi apparatus (section)

== Structure ==
[[File:Blausen 0435 GolgiApparatus.png|thumb|left|3D rendering of Golgi apparatus]]

In most eukaryotes, the Golgi apparatus is made up of a series of compartments and is a collection of fused, flattened membrane-enclosed disks known as [[cisternae]] (singular: ''cisterna'', also called "dictyosomes"), originating from vesicular clusters that bud off the endoplasmic reticulum (ER). A mammalian cell typically contains 40 to 100 stacks of cisternae.<ref name="Duran-2008">{{cite journal | vauthors = Duran JM, Kinseth M, Bossard C, Rose DW, Polishchuk R, Wu CC, Yates J, Zimmerman T, Malhotra V | title = The role of GRASP55 in Golgi fragmentation and entry of cells into mitosis | journal = Molecular Biology of the Cell | volume = 19 | issue = 6 | pages = 2579–87 | date = June 2008 | pmid = 18385516 | pmc = 2397314 | doi = 10.1091/mbc.E07-10-0998 }}</ref> Between four and eight cisternae are usually present in a stack; however, in some [[protists]], as many as sixty cisternae have been observed.<ref name="Davidson-2004"/> This collection of cisternae is broken down into ''cis'', medial, and ''trans'' compartments, making up two main networks: the '''cis Golgi network''' (CGN) and the '''trans Golgi network''' (TGN). The CGN is the first cisternal structure, and the TGN is the final, from which proteins are packaged into [[Vesicle (biology and chemistry)|vesicle]]s destined to [[lysosome]]s, secretory vesicles, or the cell surface. The TGN is usually positioned adjacent to the stack, but can also be separate from it. The TGN may act as an early [[endosome]] in yeast and plants.<ref name="Nakano-2010"/><ref name="Day-2018">{{cite journal|doi=10.1016/j.devcel.2017.12.014|pmid=29316441|pmc=5765772|title=Budding Yeast Has a Minimal Endomembrane System|journal=Developmental Cell|volume=44|issue=1|pages=56–72.e4|year=2018|last1=Day|first1=Kasey J.|last2=Casler|first2=Jason C.|last3=Glick|first3=Benjamin S.}}</ref>

There are structural and organizational differences in the Golgi apparatus among eukaryotes. In some yeasts, Golgi stacking is not observed. ''[[Pichia pastoris]]'' does have stacked Golgi, while ''Saccharomyces cerevisiae'' does not.<ref name="Nakano-2010"/> In plants, the individual stacks of the Golgi apparatus seem to operate independently.<ref name="Nakano-2010"/>

The Golgi apparatus tends to be larger and more numerous in cells that synthesize and secrete large amounts of substances; for example, the [[antibody]]-secreting [[plasma B cell]]s of the immune system have prominent Golgi complexes.{{cn|date=May 2025}}

In all eukaryotes, each cisternal stack has a ''cis'' entry face and a ''trans'' exit face. These faces are characterized by unique morphology and [[biochemistry]].<ref name="Day-2013">{{cite journal|author2-link=Lucas Andrew Staehelin | vauthors = Day KJ, Staehelin LA, Glick BS | title = A three-stage model of Golgi structure and function | journal = Histochemistry and Cell Biology | volume = 140 | issue = 3 | pages = 239–49 | date = September 2013 | pmid = 23881164 | pmc = 3779436 | doi = 10.1007/s00418-013-1128-3 }}</ref> Within individual stacks are assortments of enzymes responsible for selectively modifying protein cargo. These modifications influence the fate of the protein. The compartmentalization of the Golgi apparatus is advantageous for separating enzymes, thereby maintaining consecutive and selective processing steps: enzymes catalyzing early modifications are gathered in the ''cis'' face cisternae, and enzymes catalyzing later modifications are found in ''trans'' face cisternae of the Golgi stacks.<ref name="Alberts-1994"/><ref name="Day-2013"/>