| GOID Link to GO |
Functional Category | Description | Protein Count link to protein list |
|---|---|---|---|
| GO:0009506 | plasmodesma | A fine cytoplasmic channel, found in all higher plants, that connects the cytoplasm of one cell to that of an adjacent cell. | 463 |
| GO:0043234 | protein complex | Any macromolecular complex composed of two or more polypeptide subunits, which may or may not be identical. Protein complexes may have other associated non-protein prosthetic groups, such as nucleotides, metal ions or other small molecules. | 437 |
| GO:0016020 | membrane | Double layer of lipid molecules that encloses all cells, and, in eukaryotes, many organelles; may be a single or double lipid bilayer; also includes associated proteins. | 378 |
| GO:0016021 | integral to membrane | Penetrating at least one phospholipid bilayer of a membrane. May also refer to the state of being buried in the bilayer with no exposure outside the bilayer. When used to describe a protein, indicates that all or part of the peptide sequence is embedded in the membrane. | 332 |
| GO:0005576 | extracellular region | The space external to the outermost structure of a cell. For cells without external protective or external encapsulating structures this refers to space outside of the plasma membrane. This term covers the host cell environment outside an intracellular parasite. | 236 |
| GO:0005911 | cell-cell junction | A cell junction that forms a connection between two cells; excludes direct cytoplasmic junctions such as ring canals. | 157 |
| GO:0045121 | membrane raft | Any of the small (10-200 nm), heterogeneous, highly dynamic, sterol- and sphingolipid-enriched membrane domains that compartmentalize cellular processes. Small rafts can sometimes be stabilized to form larger platforms through protein-protein and protein-lipid interactions. | 154 |
| GO:0044425 | membrane part | Any constituent part of a membrane, a double layer of lipid molecules that encloses all cells, and, in eukaryotes, many organelles; may be a single or double lipid bilayer; also includes associated proteins. | 152 |
| GO:0045202 | synapse | The junction between a nerve fiber of one neuron and another neuron or muscle fiber or glial cell; the site of interneuronal communication. As the nerve fiber approaches the synapse it enlarges into a specialized structure, the presynaptic nerve ending, which contains mitochondria and synaptic vesicles. At the tip of the nerve ending is the presynaptic membrane; facing it, and separated from it by a minute cleft (the synaptic cleft) is a specialized area of membrane on the receiving cell, known as the postsynaptic membrane. In response to the arrival of nerve impulses, the presynaptic nerve ending secretes molecules of neurotransmitters into the synaptic cleft. These diffuse across the cleft and transmit the signal to the postsynaptic membrane. | 148 |
| GO:0005925 | focal adhesion | Small region on the surface of a cell that anchors the cell to the extracellular matrix and that forms a point of termination of actin filaments. | 148 |
| GO:0031594 | neuromuscular junction | The junction between the axon of a motor neuron and a muscle fiber. In response to the arrival of action potentials, the presynaptic button releases molecules of neurotransmitters into the synaptic cleft. These diffuse across the cleft and transmit the signal to the postsynaptic membrane of the muscle fiber, leading to a post-synaptic potential responsible of the muscle contraction. | 135 |
| GO:0045211 | postsynaptic membrane | A specialized area of membrane facing the presynaptic membrane on the tip of the nerve ending and separated from it by a minute cleft (the synaptic cleft). Neurotransmitters across the synaptic cleft and transmit the signal to the postsynaptic membrane. | 98 |
| GO:0031012 | extracellular matrix | A structure lying external to one or more cells, which provides structural support for cells or tissues; may be completely external to the cell (as in animals and bacteria) or be part of the cell (as in plants). | 85 |
| GO:0030054 | cell junction | A cellular component that forms a specialized region of connection between two cells or between a cell and the extracellular matrix. At a cell junction, anchoring proteins extend through the plasma membrane to link cytoskeletal proteins in one cell to cytoskeletal proteins in neighboring cells or to proteins in the extracellular matrix. | 78 |
| GO:0005912 | adherens junction | A cell junction at which anchoring proteins (cadherins or integrins) extend through the plasma membrane and are attached to actin filaments. | 67 |
| GO:0032991 | macromolecular complex | A stable assembly of two or more macromolecules, i.e. proteins, nucleic acids, carbohydrates or lipids, in which the constituent parts function together. | 58 |
| GO:0005923 | tight junction | An occluding cell-cell junction that is composed of a branching network of sealing strands that completely encircles the apical end of each cell in an epithelial sheet; the outer leaflets of the two interacting plasma membranes are seen to be tightly apposed where sealing strands are present. Each sealing strand is composed of a long row of transmembrane adhesion proteins embedded in each of the two interacting plasma membranes. | 56 |
| GO:0014704 | intercalated disc | A complex cell-cell junction at which myofibrils terminate in cardiomyocytes; mediates mechanical and electrochemical integration between individual cardiomyocytes. The intercalated disc contains regions of tight mechanical attachment (fasciae adherentes and desmosomes) and electrical coupling (gap junctions) between adjacent cells. | 49 |
| GO:0044456 | synapse part | Any constituent part of a synapse, the junction between a nerve fiber of one neuron and another neuron or muscle fiber or glial cell. | 38 |
| GO:0019898 | extrinsic to membrane | Loosely bound to one surface of a membrane, but not integrated into the hydrophobic region. | 34 |
| GO:0005913 | cell-cell adherens junction | An adherens junction which connects a cell to another cell. | 34 |
| GO:0060076 | excitatory synapse | A synapse in which an action potential in the presynaptic cell increases the probability of an action potential occurring in the postsynaptic cell. | 28 |
| GO:0043296 | apical junction complex | A functional unit located near the cell apex at the points of contact between epithelial cells, which in vertebrates is composed of the tight junction, the zonula adherens, and desmosomes and in some invertebrates, such as Drosophila, is composed of the subapical complex (SAC), the zonula adherens and the septate junction. Functions in the regulation of cell polarity, tissue integrity and intercellular adhesion and permeability. | 24 |
| GO:0097060 | synaptic membrane | A specialized area of membrane on either the presynaptic or the postsynaptic side of a synapse, the junction between a nerve fiber of one neuron and another neuron or muscle fiber or glial cell. | 23 |
| GO:0032993 | protein-DNA complex | A macromolecular complex containing both protein and DNA molecules. | 21 |
| GO:0031224 | intrinsic to membrane | Located in a membrane such that some covalently attached portion of the gene product, for example part of a peptide sequence or some other covalently attached group such as a GPI anchor, spans or is embedded in one or both leaflets of the membrane. | 16 |
| GO:0060077 | inhibitory synapse | A synapse in which an action potential in the presynaptic cell reduces the probability of an action potential occurring in the postsynaptic cell. | 15 |
| GO:0032279 | asymmetric synapse | A type of synapse occurring between an axon and a dendritic spine or dendritic shaft. Asymmetric synapses, the most abundant synapse type in the central nervous system, involve axons that contain predominantly spherical vesicles and contain a thickened postsynaptic density. | 15 |
| GO:0005918 | septate junction | A cell-cell junction that forms a continuous band around each cell in an epithelium; within the septate junction the membranes of adjacent cells maintain a constant distance of approximately 15 nm; found in invertebrates. | 14 |
| GO:0031974 | membrane-enclosed lumen | The enclosed volume within a sealed membrane or between two sealed membranes. Encompasses the volume enclosed by the membranes of a particular organelle, e.g. endoplasmic reticulum lumen, or the space between the two lipid bilayers of a double membrane surrounding an organelle, e.g. nuclear envelope lumen. | 12 |
| GO:0005920 | smooth septate junction | A septate junction that lacks the regular arrays of electron-dense septae found in pleated septate junctions. | 12 |
| GO:0005921 | gap junction | A cell-cell junction that is composed of an array of small channels that permit small molecules to pass from one cell to another. At gap junctions, the membranes of two adjacent cells are separated by a uniform narrow gap of about 2-4 nm that is spanned by channel-forming proteins called connexins, which form hexagonal tubes called connexons. | 9 |
| GO:0005916 | fascia adherens | A cell-cell adherens junction that contains the transmembrane protein N-cadherin, which interacts with identical molecules from neighboring cells to form a tight mechanical intercellular link; forms a large portion of the intercalated disc, the structure at which myofibrils terminate in cardiomyocytes. | 8 |
| GO:0031225 | anchored to membrane | Tethered to a membrane by a covalently attached anchor, such as a lipid group, that is embedded in the membrane. When used to describe a protein, indicates that none of the peptide sequence is embedded in the membrane. | 8 |
| GO:0044420 | extracellular matrix part | Any constituent part of the extracellular matrix, the structure lying external to one or more cells, which provides structural support for cells or tissues; may be completely external to the cell (as in animals) or be part of the cell (as often seen in plants). | 8 |
| GO:0030056 | hemidesmosome | A cell-substrate junction that forms a point of contact between the basal surface of epithelial cells and the basal lamina. Morphologically resembles desmosomes; attached to intermediate filaments. | 8 |
| GO:0005915 | zonula adherens | A cell-cell adherens junction which forms a continuous belt near the apex of epithelial cells. | 7 |
| GO:0005919 | pleated septate junction | A septate junction in which regular arrays of electron-dense septae span the intermembrane space. | 7 |
| GO:0046581 | intercellular canaliculus | An extremely narrow tubular channel located between adjacent cells. An instance of this is the secretory canaliculi occurring between adjacent parietal cells in the gastric mucosa of vertebrates. | 7 |
| GO:0030055 | cell-substrate junction | A cell junction that forms a connection between a cell and the extracellular matrix. | 6 |
| GO:0005927 | muscle tendon junction | A cell-substrate junction found at the terminal anchorage site of skeletal muscle cells to tendons. | 6 |
| GO:0043083 | synaptic cleft | The narrow gap that separates the presynaptic and postsynaptic membranes, into which neurotransmitter is released. | 5 |
| GO:0030057 | desmosome | A cell-cell junction in which: on the cytoplasmic surface of each interacting plasma membrane is a dense plaque composed of a mixture of intracellular anchor proteins; a bundle of keratin intermediate filaments is attached to the surface of each plaque; transmembrane adhesion proteins of the cadherin family bind to the plaques and interact through their extracellular domains to hold the adjacent membranes together by a Ca2+-dependent mechanism. | 5 |
| GO:0071666 | Slit-Robo signaling complex | A protein-carbohydrate complex that consists of a transmembrane roundabout (Robo) receptor, an extracellular Slit ligand and heparin/heparan sulfate. | 5 |
| GO:0043226 | organelle | Organized structure of distinctive morphology and function. Includes the nucleus, mitochondria, plastids, vacuoles, vesicles, ribosomes and the cytoskeleton, and prokaryotic structures such as anammoxosomes and pirellulosomes. Excludes the plasma membrane. | 4 |
| GO:0005926 | connecting hemi-adherens junction | A cell-substrate adherens junction, also known as a hemiadherens junction (HAJ) that forms one of a pair of junctions in opposing cells that are separated by only 30-40nm, with a thin line of extracellular electron-dense material in between; found where muscles attach to epidermal cells directly (in insects). | 3 |
| GO:0005924 | cell-substrate adherens junction | An adherens junction which connects a cell to the extracellular matrix. | 3 |
| GO:0043674 | columella | A rod-like element of the sexine and ectexine, supporting either the tectum (the layer of sexine which forms a roof over the columella), or supporting a caput (an architectural element on top of a columella). | 3 |
| GO:0009295 | nucleoid | The region of a virus, bacterial cell, mitochondrion or chloroplast to which the nucleic acid is confined. | 3 |
| GO:0005914 | spot adherens junction | A small cell-cell adherens junction assembled during the cellularization stage of insect embyrogenesis; spot adherens junctions later fuse to form the zonula adherens. | 3 |
| GO:0032280 | symmetric synapse | A type of synapse occurring primarily on dendrite shafts and neuronal cell bodies. Symmetric synapses involve axons containing clusters of predominantly flattened or elongated vesicles and do not contain a prominent postsynaptic density. | 2 |
| GO:0044291 | cell-cell contact zone | Extended zone of intimate apposition between two cells containing one or more types of intercellular junctions, e.g., the intercalated disk of muscle. | 2 |
| GO:0036062 | presynaptic periactive zone | A region that surrounds the active zone of the presynaptic plasma membrane, and is specialized for the control of synaptic development. | 2 |
| GO:0005623 | cell | The basic structural and functional unit of all organisms. Includes the plasma membrane and any external encapsulating structures such as the cell wall and cell envelope. | 1 |
| GO:0070160 | occluding junction | A cell-cell junction that seals cells together in an epithelium in a way that prevents even small molecules from leaking from one side of the sheet to the other. | 1 |
| GO:0036057 | slit diaphragm | A specialized cell-cell junction found between the interdigitating foot processes of the glomerular epithelium (the podocytes) in the vertebrate kidney, which is adapted for facilitating glomerular filtration. | 1 |
| GO:0019867 | outer membrane | The external membrane of Gram-negative bacteria or certain organelles such as mitochondria and chloroplasts; freely permeable to most ions and metabolites. | 1 |
| GO:0070469 | respiratory chain | The protein complexes that form the electron transport system (the respiratory chain), associated with a cell membrane, usually the plasma membrane (in prokaryotes) or the inner mitochondrial membrane (on eukaryotes). The respiratory chain complexes transfer electrons from an electron donor to an electron acceptor and are associated with a proton pump to create a transmembrane electrochemical gradient. | 1 |
| GO:0005917 | nephrocyte diaphragm | A specialized cell-cell junction found between nephrocytes of the insect kidney, which is adapted for filtration of hemolymph. The insect nephrocyte is anatomically and functionally similarity to the glomerular podocyte of vertebrates. | 1 |