EMI domain | |||||||||
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Identifiers | |||||||||
Symbol | EMI | ||||||||
Pfam | PF07546 | ||||||||
InterPro | IPR011489 | ||||||||
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In molecular biology, the EMI domain, first named after its presence in proteins of the EMILIN family, is a small cysteine-rich protein domain of around 75 amino acids. The EMI domain is most often found at the N terminus of metazoan extracellular proteins that are forming or are compatible with multimer formation. [1] It is found in association with other domains, such as C1q, laminin-type EGF-like, collagen-like, FN3, WAP, ZP or FAS1. [2] It has been suggested that the EMI domain could be a protein-protein interaction module, as the EMI domain of EMILIN-1 was found to interact with the C1q domain of EMILIN-2. [1]
The EMI domain possesses six highly conserved cysteine residues, which likely form disulphide bonds. Other key features of the EMI domain are the C-C-x-G-[WYFH] pattern, a hydrophobic position just preceding the first cysteine (Cys1) of the domain and a cluster of hydrophobic residues between Cys3 and Cys4. The EMI domain could be made of two sub-domains, the fold of the second one sharing similarities with the C-terminal sub-module characteristic of EGF-like domains. [2]
Proteins known to contain an EMI domain include:
Matrix metalloproteinases (MMPs), also known as matrix metallopeptidases or matrixins, are metalloproteinases that are calcium-dependent zinc-containing endopeptidases; other family members are adamalysins, serralysins, and astacins. The MMPs belong to a larger family of proteases known as the metzincin superfamily.
Laminins are high-molecular weight proteins of the extracellular matrix. They are a major component of the basal lamina, a protein network foundation for most cells and organs. The laminins are an important and biologically active part of the basal lamina, influencing cell differentiation, migration, and adhesion.
Caspase recruitment domains, or caspase activation and recruitment domains (CARDs), are interaction motifs found in a wide array of proteins, typically those involved in processes relating to inflammation and apoptosis. These domains mediate the formation of larger protein complexes via direct interactions between individual CARDs. CARD domains are found on a strikingly wide range of proteins, including helicases, kinases, mitochondrial proteins, caspases, and other cytoplasmic factors.
Teneurins are a family of phylogenetically conserved single-pass transmembrane glycoproteins expressed during pattern formation and morphogenesis. The name refers to "ten-a" and "neurons", the primary site of teneurin expression. Ten-m refers to tenascin-like protein major.
Protein disulfide-isomerase A3 (PDIA3), also known as glucose-regulated protein, 58-kD (GRP58), is an isomerase enzyme. This protein localizes to the endoplasmic reticulum (ER) and interacts with lectin chaperones calreticulin and calnexin (CNX) to modulate folding of newly synthesized glycoproteins. It is thought that complexes of lectins and this protein mediate protein folding by promoting formation of disulfide bonds in their glycoprotein substrates.
Fibulin (FY-beau-lin) is the prototypic member of a multigene family, currently with seven members. Fibulin-1 is a calcium-binding glycoprotein. In vertebrates, fibulin-1 is found in blood and extracellular matrices. In the extracellular matrix, fibulin-1 associates with basement membranes and elastic fibers. The association with these matrix structures is mediated by its ability to interact with numerous extracellular matrix constituents including fibronectin, proteoglycans, laminins and tropoelastin. In blood, fibulin-1 binds to fibrinogen and incorporates into clots.
Matrilysin also known as matrix metalloproteinase-7 (MMP-7), pump-1 protease (PUMP-1), or uterine metalloproteinase is an enzyme in humans that is encoded by the MMP7 gene. The enzyme has also been known as matrin, putative metalloproteinase-1, matrix metalloproteinase pump 1, PUMP-1 proteinase, PUMP, metalloproteinase pump-1, putative metalloproteinase, MMP).
Fibrillin-1 is a protein that in humans is encoded by the FBN1 gene, located on chromosome 15.
The EGF-like domain is an evolutionary conserved protein domain, which derives its name from the epidermal growth factor where it was first described. It comprises about 30 to 40 amino-acid residues and has been found in a large number of mostly animal proteins. Most occurrences of the EGF-like domain are found in the extracellular domain of membrane-bound proteins or in proteins known to be secreted. An exception to this is the prostaglandin-endoperoxide synthase. The EGF-like domain includes 6 cysteine residues which in the epidermal growth factor have been shown to form 3 disulfide bonds. The structures of 4-disulfide EGF-domains have been solved from the laminin and integrin proteins. The main structure of EGF-like domains is a two-stranded β-sheet followed by a loop to a short C-terminal, two-stranded β-sheet. These two β-sheets are usually denoted as the major (N-terminal) and minor (C-terminal) sheets. EGF-like domains frequently occur in numerous tandem copies in proteins: these repeats typically fold together to form a single, linear solenoid domain block as a functional unit.
CED-12 is a cytoplasmic, PH-domain containing adaptor protein found in Caenorhabditis elegans and Drosophila melanogaster. CED-12 is a homolog to the ELMO protein found in mammals. This protein is involved in Rac-GTPase activation, apoptotic cell phagocytosis, cell migration, and cytoskeletal rearrangements.
Matrix metallopeptidase 27 also known as MMP-27 is an enzyme which in humans is encoded by the MMP27 gene.
Notch proteins are a family of type-1 transmembrane proteins that form a core component of the Notch signaling pathway, which is highly conserved in metazoans. The Notch extracellular domain (NECD) mediates interactions with DSL family ligands, allowing it to participate in juxtacrine signaling.The Notch intracellular domain (NICD) acts as a transcriptional activator when in complex with CSL family transcription factors. Members of this Type 1 transmembrane protein family share several core structures, including an extracellular domain consisting of multiple epidermal growth factor (EGF)-like repeats and an intracellular domain transcriptional activation domain (TAD). Notch family members operate in a variety of different tissues and play a role in a variety of developmental processes by controlling cell fate decisions. Much of what is known about Notch function comes from studies done in Caenorhabditis elegans (C.elegans) and Drosophila melanogaster. Human homologs have also been identified, but details of Notch function and interactions with its ligands are not well known in this context.
CUB domain is an evolutionarily conserved protein domain.
Von Willebrand factor, type C is a protein domain is found in various blood plasma proteins: complement factors B, C2, CR3 and CR4; the integrins (I-domains); collagen types VI, VII, XII and XIV; and other extracellular proteins.
In molecular biology the ZZ-type zinc finger domain is a type of protein domain that was named because of its ability to bind two zinc ions. These domains contain 4-6 Cys residues that participate in zinc binding, including a Cys-X2-Cys motif found in other zinc finger domains. These zinc fingers are thought to be involved in protein-protein interactions. The structure of the ZZ domain shows that it belongs to the family of cross-brace zinc finger motifs that include the PHD, RING, and FYVE domains. ZZ-type zinc finger domains are found in:
A Link domain or Link module, also known as Xlink domain, is a protein domain that binds to hyaluronic acid. It is important in blood cell migration and apoptosis. The link domain is found in some extracellular proteins in vertebrates such as the hyalectans. It appears to be involved in extracellular matrix assembly and stability, cell adhesion, and migration.
SNED1 is a human protein expressed at low levels in a wide range of tissues. The protein is soluble and found in circulating blood and the conceptually translated protein has four domains of interest. These domains include a nidgen (NIDO) domain, three fibronectin type III (FN3) domains, several calcium binding EGF-like domains, and one complement control protein (CCP) domain. The gene is found on chromosome 2, locus q37.3. The mRNA was isolated from the spleen and is 6834bp in length. The conceptually translated protein is 1178aa long. This protein is predicted to interact with somatostatin, spermidine synthase and TMEM132C.
The GPIb-IX-V complex is a profuse membrane receptor complex originating in megakaryocytes and exclusively functional on the surface of platelets. It primarily functions to mediate the first critical step in platelet adhesion, by facilitating binding to von Willebrand factor (VWF) on damaged sub-endothelium under conditions of high fluid shear stress. Although the primary ligand for the GPIb-V-IX receptor is VWF, it can also bind to a number of other ligands in the circulation such as thrombin, P-selectin, factor XI, factor XII, high molecular weight kininogen as well as bacteria. GPIb-IX-V offers a critical role in thrombosis, metastasis, and the life cycle of platelets, and is implicated in a number of thrombotic pathological processes such as stroke or myocardial infarction.
Teneurin-3, also known as Ten-m3, Odz3, Ten-m/Odz3, Tenascin-like molecule major 3 or Teneurin transmembrane protein 3, is a protein that, in humans, is encoded by the TENM3, or ODZ3, gene. Ten-m3 is a ~300 kDa type II transmembrane glycoprotein that is a member of the teneurin/Ten-m/Odz family. The teneurin family currently consists of four members: Ten-m1-Ten-m4. Ten-ms are conserved across both vertebrate and invertebrate species. They are expressed in distinct, but often interconnected, areas of the developing nervous system and in some non-neural tissues. Like the Ten-m family, Ten-m3 plays a critical role in regulating connectivity of the nervous system, particularly in axon pathfinding and synaptic organisation in the motor and visual system. Mutation in the TENM3/ODZ3 gene in humans has been associated with the eye condition, microphthalmia.
Ced-3 is one of the major protein components of the programmed cell death (PCD) pathway for Caenorhabditis elegans. There are in total 14 genes that are involved in programmed cell death, other important ones including ced-4 and ced-9 genes. The healthy nematode worm will require 131 somatic cell deaths out of the 1090 cells during the developmental stages. The gene initially encodes for a prototypical caspase (procaspase) where the active cysteine residue cleaves aspartate residues, thus becoming a functional caspase. Ced-3 is an executioner caspase that must dimerize with itself and be initiated by ced-4 in order to become active. Once active, it will have a series of reactions that will ultimately lead to the apoptosis of targeted cells.