The Golgi apparatus is a central hub in the endomembrane system of human cells, placed at the intersection of the endosomal-, secretory- and lysosomal pathways. It consists of several stacks of flattened cisternae and tubular connections, forming a ribbon-like structure that is highly dynamic. The Golgi apparatus is polarized and can be sub-divided into the cis-, medial- and trans-Golgi compartments. Generally, vesicles carrying proteins and membrane components from the ER enter at the tubular cis-Golgi network. As the cargo molecules progress through the Golgi compartments, they are subjected to processing and modifications, such as glycosylation, by various enzymes that reside in the Golgi membranes. Finally, proteins and membrane components are sorted and exit in vesicles that bud from the trans-Golgi network. In recent years, the Golgi apparatus has also been recognized as an important contributor to the coordination and regulation of numerous higher-order cellular processes, including mitosis and stress responses. In this sense, the Golgi apparatus acts as a cell sensor that responds to various signaling events and communicates with other cellular compartments.
The Golgi apparatus is a rather large organelle that is located next to the nucleus, close to the centrosome. The morphology and size can vary between cell lines, and in response to various cellular processes. The Golgi apparatus is particularly extensive in secretory cells.
Read more about the proteome of the Golgi apparatus.