Subcellular localization
The cells of eukaryotic organisms are elaborately subdivided into functionally-distinct membrane-bound compartments. Some major constituents of eukaryotic cells are: extracellular space, cytoplasm, nucleus, mitochondria, Golgi apparatus, endoplasmic reticulum, peroxisome, vacuoles, cytoskeleton, nucleoplasm, nucleolus, nuclear matrix and ribosomes.
Bacteria also have subcellular localizations that can be separated when the cell is fractionated. The most common localizations referred to include the cytoplasm, the cytoplasmic membrane, the cell wall and the extracellular environment. The cytoplasm, the cytoplasmic membrane and the cell wall are subcellular localizations, whereas the extracellular environment is clearly not. Most Gram-negative bacteria also contain an outer membrane and periplasmic space. Unlike eukaryotes, most bacteria contain no membrane-bound organelles, however there are some exceptions.Protein Subcellular Location Databases
The experimentally determined subcellular locations of proteins can be found in , , and in a few more specialized resources, such as .
There are also several subcellular location databases with computational predictions, such as , , for protein subcellular locations of human and animals, and for protein subcellular locations of all protists.
