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Membrane-associated Guanylate Kinase
The membrane-associated guanylate kinases (MAGUK) are a superfamily of proteins. The MAGUKs are defined by their inclusion of PDZ, SH3 and GUK domains, although many of them also contain regions homologous of CaMKII, WW and L27 domains. The GUK domain that they have is structurally very similar to that of the guanylate kinases, however it is known to be catalytically inactive as the P-Loop which binds ATP is absent. It is thought that the MAGUKs have subfunctionalized the GUK domain for their own purposes, primarily based on its ability to form protein–protein interactions with cytoskeleton proteins, microtubule/actin based machinery and molecules involved in signal transduction. MAGUKs also contain multiple PDZ domains, or short peptide binding sequences commonly bind to the C-terminus of interacting proteins. The number of PDZ domain copies varies between different members of the MAGUK family. The PDZ domains found within each family member often have different binding p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conserved Domain Database
The Conserved Domain Database (CDD) is a database of well-annotated multiple sequence alignment models and derived database search models, for ancient domains and full-length proteins. Philosophy Domains can be thought of as distinct functional and/or structural units of a protein. These two classifications coincide rather often, as a matter of fact, and what is found as an independently folding unit of a polypeptide chain also carries specific function. Domains are often identified as recurring (sequence or structure) units, which may exist in various contexts. In molecular evolution such domains may have been utilized as building blocks, and may have been recombined in different arrangements to modulate protein function. CDD defines conserved domains as recurring units in molecular evolution, the extents of which can be determined by sequence and structure analysis. The goal of the NCBI conserved domain curation project is to provide database users with insights into how patt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoskeleton
The cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including those of bacteria and archaea. In eukaryotes, it extends from the cell nucleus to the cell membrane and is composed of similar proteins in the various organisms. It is composed of three main components, microfilaments, intermediate filaments and microtubules, and these are all capable of rapid growth or disassembly dependent on the cell's requirements. A multitude of functions can be performed by the cytoskeleton. Its primary function is to give the cell its shape and mechanical resistance to deformation, and through association with extracellular connective tissue and other cells it stabilizes entire tissues. The cytoskeleton can also contract, thereby deforming the cell and the cell's environment and allowing cells to migrate. Moreover, it is involved in many cell signaling pathways and in the uptake of extracellular material ( endocytosis), the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DLG4
PSD-95 (postsynaptic density protein 95) also known as SAP-90 (synapse-associated protein 90) is a protein that in humans is encoded by the ''DLG4'' (discs large homolog 4) gene. PSD-95 is a member of the membrane-associated guanylate kinase (MAGUK) family. With PSD-93 it is recruited into the same NMDA receptor and potassium channel clusters. These two MAGUK proteins may interact at postsynaptic sites to form a multimeric scaffold for the clustering of receptors, ion channels, and associated signaling proteins. PSD-95 is the best studied member of the MAGUK-family of PDZ domain-containing proteins. Like all MAGUK-family proteins, its basic structure includes three PDZ domains, an SH3 domain, and a guanylate kinase-like domain (GK) connected by disordered linker regions. It is almost exclusively located in the post synaptic density of neurons, and is involved in anchoring synaptic proteins. Its direct and indirect binding partners include neuroligin, NMDA receptors, AMPA rece ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DLG3
Disks large homolog 3 (DLG3) also known as neuroendocrine-DLG or synapse-associated protein 102 (SAP-102) is a protein that in humans is encoded by the ''DLG3'' gene. DLG3 is a member of the membrane-associated guanylate kinase (MAGUK) superfamily of proteins. Interactions DLG3 has been shown to interact with: * APC, * CRIPT, * DLG4, * EXOC3, * EXOC4, * GRIN2A, * GRIN2B, * GRIN2C, * KCNJ12 * PTK2B, and * SYNGAP1. Model organisms Model organisms have been used in the study of DLG3 function. A conditional knockout mouse line called ''Dlg3tm1a(EUCOMM)Wtsi'' was generated at the Wellcome Trust Sanger Institute. Male and female animals underwent a standardized phenotypic screen In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological proper ... to determine the effects of deletion. Additio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DLG2
Disks large homolog 2 (DLG2) also known as channel-associated protein of synapse-110 (chapsyn-110) or postsynaptic density protein 93 (PSD-93) is a protein that in humans is encoded by the ''DLG2'' gene. Function Chapsyn-110/PSD-93 a member of the membrane-associated guanylate kinase (MAGUK) family. The protein forms a heterodimer with a related family member that may interact at postsynaptic sites to form a multimeric scaffold for the clustering of receptors, ion channels, and associated signaling proteins. Alternatively spliced transcript variants encoding distinct isoforms have been described but their full-length nature has yet to be completely determined. Model organisms Model organisms have been used in the study of DLG2 function. A knockout mouse line, called ''Dlg2tm1Dsb'' was generated. Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion. Twenty four tests were carried out on homozygous mutant mice and five signifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DLG1
Discs large homolog 1 (DLG1), also known as synapse-associated protein 97 or SAP97, is a scaffold protein that in humans is encoded by the ''SAP97'' gene. SAP97 is a mammalian MAGUK-family member protein that is similar to the Drosophila protein Dlg1 (the protein is alternatively referred to as hDlg1, and the human gene is DLG1). SAP97 is expressed throughout the body in epithelial cells. In the brain it is involved in the trafficking of ionotropic receptors from the endoplasmic reticulum to the plasma membrane, and may be involved in the trafficking AMPAR during synaptic plasticity. Function SAP97 is expressed throughout the body in epithelial cells, including the kidney and brain. There is some evidence that SAP97 regulates cell-to-cell adhesion during cell death, and may interact with HPV. In the brain, SAP97's function is involved in the trafficking of transmembrane receptors from the ER to the plasma membrane. SAP97's function has been investigated by reducing its expr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-terminus
The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is translated from messenger RNA, it is created from N-terminus to C-terminus. The convention for writing peptide sequences is to put the C-terminal end on the right and write the sequence from N- to C-terminus. Chemistry Each amino acid has a carboxyl group and an amine group. Amino acids link to one another to form a chain by a dehydration reaction which joins the amine group of one amino acid to the carboxyl group of the next. Thus polypeptide chains have an end with an unbound carboxyl group, the C-terminus, and an end with an unbound amine group, the N-terminus. Proteins are naturally synthesized starting from the N-terminus and ending at the C-terminus. Function C-terminal retention signals While the N-terminus of a protein often c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Transduction
Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinases, which ultimately results in a cellular response. Proteins responsible for detecting stimuli are generally termed receptors, although in some cases the term sensor is used. The changes elicited by ligand binding (or signal sensing) in a receptor give rise to a biochemical cascade, which is a chain of biochemical events known as a signaling pathway. When signaling pathways interact with one another they form networks, which allow cellular responses to be coordinated, often by combinatorial signaling events. At the molecular level, such responses include changes in the transcription or translation of genes, and post-translational and conformational changes in proteins, as well as changes in their location. These molecular events are the basic mechanisms controlling cell growth, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actin
Actin is a family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils. It is found in essentially all eukaryotic cells, where it may be present at a concentration of over 100 μM; its mass is roughly 42 kDa, with a diameter of 4 to 7 nm. An actin protein is the monomeric subunit of two types of filaments in cells: microfilaments, one of the three major components of the cytoskeleton, and thin filaments, part of the contractile apparatus in muscle cells. It can be present as either a free monomer called G-actin (globular) or as part of a linear polymer microfilament called F-actin (filamentous), both of which are essential for such important cellular functions as the mobility and contraction of cells during cell division. Actin participates in many important cellular processes, including muscle contraction, cell motility, cell division and cytokinesis, vesicle and organelle movement, cell sign ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtubule
Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27 nm and have an inner diameter between 11 and 15 nm. They are formed by the polymerization of a dimer of two globular proteins, alpha and beta tubulin into protofilaments that can then associate laterally to form a hollow tube, the microtubule. The most common form of a microtubule consists of 13 protofilaments in the tubular arrangement. Microtubules play an important role in a number of cellular processes. They are involved in maintaining the structure of the cell and, together with microfilaments and intermediate filaments, they form the cytoskeleton. They also make up the internal structure of cilia and flagella. They provide platforms for intracellular transport and are involved in a variety of cellular processes, including the movement of secretory vesicles, organell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Superfamily
A protein superfamily is the largest grouping (clade) of proteins for which common ancestry can be inferred (see homology (biology), homology). Usually this common ancestry is inferred from structural alignment and mechanistic similarity, even if no sequence similarity is evident. Sequence homology can then be deduced even if not apparent (due to low sequence similarity). Superfamilies typically contain several protein families which show sequence similarity within each family. The term ''protein clan'' is commonly used for protease and glycosyl hydrolases superfamilies based on the MEROPS and CAZy classification systems. Identification Superfamilies of proteins are identified using a number of methods. Closely related members can be identified by different methods to those needed to group the most evolutionarily divergent members. Sequence similarity Historically, the similarity of different amino acid sequences has been the most common method of inferring Sequence homology, h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
