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Tensin
Tensin was first identified as a 220 kDa multi-domain protein localized to the specialized regions of plasma membrane called integrin-mediated focal adhesions (which are formed around a transmembrane core of an αβ integrin heterodimer). Genome sequencing and comparison have revealed the existence of four tensin genes in humans. These genes appear to be related by ancient instances of gene duplication. Tensin binds to actin filaments and contains a phosphotyrosine-binding (PTB) domain at the C-terminus, which interacts with the cytoplasmic tail of β integrins. These interactions allow tensin to link actin filaments to integrin receptors. Several factors induce tyrosine phosphorylation of tensin. Thus, tensin functions as a platform for assembly and disassembly of signaling complexes at focal adhesions by recruiting tyrosine-phosphorylated signaling molecules, and also by providing interaction sites for other proteins. Haynie, by contrast, argues in a review of tensin structure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphotyrosine-binding Domain
In molecular biology, Phosphotyrosine-binding domains are protein domains which bind to phosphotyrosine. The phosphotyrosine-binding domain (PTB, also phosphotyrosine-interaction or PI domain) in the protein tensin tends to be found at the C-terminus. Tensin is a multi-domain protein that binds to actin filaments and functions as a focal-adhesion molecule (focal adhesions are regions of plasma membrane through which cells attach to the extracellular matrix). Human tensin has actin-binding sites, an SH2 () domain and a region similar to the tumour suppressor PTEN. The PTB domain interacts with the cytoplasmic tails of beta integrin by binding to an NPXY motif. The phosphotyrosine-binding domain of insulin receptor substrate-1 is not related to the phosphotyrosine-binding domain of tensin. Insulin receptor substrate-1 proteins contain both a pleckstrin homology domain and a phosphotyrosine binding (PTB) domain. The PTB domains facilitate interaction with the activated tyrosi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma Membrane
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of cells and organelles, being selectively permeable to ions an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Focal Adhesions
In cell biology, focal adhesions (also cell–matrix adhesions or FAs) are large macromolecular assemblies through which mechanical force and regulatory signals are transmitted between the extracellular matrix (ECM) and an interacting cell. More precisely, focal adhesions are the sub-cellular structures that mediate the regulatory effects (i.e., signaling events) of a cell in response to ECM adhesion. Focal adhesions serve as the mechanical linkages to the ECM, and as a biochemical signaling hub to concentrate and direct numerous signaling proteins at sites of integrin binding and clustering. Structure and function Focal adhesions are integrin-containing, multi-protein structures that form mechanical links between intracellular actin bundles and the extracellular substrate in many cell types. Focal adhesions are large, dynamic protein complexes through which the cytoskeleton of a cell connects to the ECM. They are limited to clearly defined ranges of the cell, at which the plas ... [...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] |
Protein Tyrosine Phosphatase
Protein tyrosine phosphatases (EC 3.1.3.48, systematic name protein-tyrosine-phosphate phosphohydrolase) are a group of enzymes that remove phosphate groups from phosphorylated tyrosine residues on proteins: : proteintyrosine phosphate + H2O = proteintyrosine + phosphate Protein tyrosine (pTyr) phosphorylation is a common post-translational modification that can create novel recognition motifs for protein interactions and cellular localization, affect protein stability, and regulate enzyme activity. As a consequence, maintaining an appropriate level of protein tyrosine phosphorylation is essential for many cellular functions. Tyrosine-specific protein phosphatases (PTPase; ) catalyse the removal of a phosphate group attached to a tyrosine residue, using a cysteinyl-phosphate enzyme intermediate. These enzymes are key regulatory components in signal transduction pathways (such as the MAP kinase pathway) and cell cycle control, and are important in the control of cell growth, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase
The enzyme phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase (EC 3.1.3.67) catalyzes the chemical reaction :1-phosphatidyl-1D-''myo''-inositol 3,4,5-trisphosphate + H2O = 1-phosphatidyl-1D-''myo''inositol 4,5-bisphosphate + phosphate This enzyme class belongs to the family of hydrolases, specifically those acting on phosphoric monoester bonds. The systematic name is 1-phosphatidyl-D-''myo''inositol-3,4,5-trisphosphate 3-phosphohydrolase. Other names in common use include PTEN, MMAC1, and phosphatidylinositol-3,4,5-trisphosphate 3-phosphohydrolase. PTEN also refers to a member of the class, phosphatase and tensin homolog. This enzyme participates in 10 metabolic pathways: inositol phosphate metabolism, phosphatidylinositol signaling system, p53 signaling pathway, focal adhesion, tight junction, endometrial cancer, glioma, prostate cancer, melanoma, and small cell lung cancer. It employs one cofactor, magnesium Magnesium is a chemical element with the symbol Mg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PTEN (gene)
Phosphatase and tensin homolog (PTEN) is a phosphatase in humans and is encoded by the ''PTEN'' gene. Mutations of this gene are a step in the development of many cancers, specifically glioblastoma, lung cancer, breast cancer, and prostate cancer. Genes corresponding to PTEN (orthologs) have been identified in most mammals for which complete genome data are available. ''PTEN'' acts as a tumor suppressor gene through the action of its phosphatase protein product. This phosphatase is involved in the regulation of the cell cycle, preventing cells from growing and dividing too rapidly. It is a target of many anticancer drugs. The protein encoded by this gene is a phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase. It contains a tensin-like domain as well as a catalytic domain similar to that of the dual specificity protein tyrosine phosphatases. Unlike most of the protein tyrosine phosphatases, this protein preferentially dephosphorylates phosphoinositide substrates. It nega ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auxilin
Putative tyrosine-protein phosphatase auxilin is an enzyme that in humans is encoded by the ''DNAJC6'' gene. Function DNAJC6 belongs to the evolutionarily conserved DNAJ/HSP40 family of proteins, which regulate molecular chaperone activity by stimulating ATPase activity. DNAJ proteins may have up to 3 distinct domains: a conserved 70-amino acid J domain, usually at the N terminus, a glycine/phenylalanine (G/F)-rich region, and a cysteine-rich domain containing 4 motifs resembling a zinc-finger domain (Ohtsuka and Hata, 2000). Structure The protein tyrosine phosphatase domain and C2 domain pair of auxilin, located near the N-terminus of the polypeptide, constitute a superdomain, a tandem arrangement of two or more nominally unrelated domains that form a single heritable unit. The phosphatase domain belongs to the auxilin subfamily of lipid phosphatases and is predicted to be catalytically inactive. References External links * Further reading * * * * {{C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C2 Domain
A C2 domain is a protein structural domain involved in targeting proteins to cell membranes. The typical version (PKC-C2) has a beta-sandwich composed of 8 beta sheet, β-strands that co-ordinates two or three calcium ions, which bind in a cavity formed by the first and final loops of the domain, on the membrane binding face. Many other C2 domain families don't have calcium binding activity. Coupling with other domains C2 domains are frequently found coupled to enzyme, enzymatic domains; for example, the C2 domain in PTEN (gene), PTEN, brings the phosphatase domain into contact with the plasma membrane, where it can dephosphorylate its substrate, Phosphatidylinositol (3,4,5)-trisphosphate, phosphatidylinositol (3,4,5)-trisphosphate (PIP3), without removing it from the membrane - which would be energetically very costly. PTEN consists of two domains, a protein tyrosine phosphatase domain and a C2 domain. This domain pair constitutes a superdomain, a heritable unit that is found in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CDNA
In genetics, complementary DNA (cDNA) is DNA synthesized from a single-stranded RNA (e.g., messenger RNA (mRNA) or microRNA (miRNA)) template in a reaction catalyzed by the enzyme reverse transcriptase. cDNA is often used to express a specific protein in a cell that does not normally express that protein (i.e., heterologous expression), or to sequence or quantify mRNA molecules using DNA based methods (qPCR, RNA-seq). cDNA that codes for a specific protein can be transferred to a recipient cell for expression, often bacterial or yeast expression systems. cDNA is also generated to analyze transcriptomic profiles in bulk tissue, single cells, or single nuclei in assays such as microarrays, qPCR, and RNA-seq. cDNA is also produced naturally by retroviruses (such as HIV-1, HIV-2, simian immunodeficiency virus, etc.) and then integrated into the host's genome, where it creates a provirus. The term ''cDNA'' is also used, typically in a bioinformatics context, to refer to an mR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
