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Bacterial Proteins definition: Proteins found in any species of bacterium.
bacterial protein definition: proteins found in any species of bacterium.
Bacterial Protein definition: Proteins that originated from bacteria sources.
Blood Proteins definition: Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.
blood protein definition: protein present in blood serum or plasma.
Carrier Proteins definition: Transport proteins that carry specific substances in the blood or across cell membranes.
transport protein definition: diverse group of proteins which serve as carriers of ligands through solubility barriers such as aqueous body fluids (for lipoid hormones) or lipid membranes (for inorganic ions).
Transport Protein definition: Proteins that carry specific substances in the blood or across cell membranes.
Cerebrospinal Fluid Proteins definition: Proteins in the cerebrospinal fluid, normally albumin and globulin present in the ratio of 8 to 1. Increases in protein levels are of diagnostic value in neurological diseases. (Brain and Bannister's Clinical Neurology, 7th ed, p221)
complement definition: system of serum proteins that interact with antigen antibody complex to produce cytolytic, chemotaxic, anaphylactic, and other effects.
Complement definition: The complement system is a complex system of serum proteins that interact in a cascade. Many of the early components are serine proteases that activate each other sequentially. This complement system consists of three separate activation triggers: (1) Ab binding to a cell surface, (2) formation of immune complexes, and (3) a carbohydrate component of a microbe's cell membrane. Along with this triggers, there are also two sets of mechanisms. Both of these mechanisms, classical pathway and alternative or properdin pathway, make MAC (Membrane Attack Complex), which can lyse and destroy the cell.
Complement System Proteins definition: Serum glycoproteins participating in the host defense mechanism of COMPLEMENT ACTIVATION that creates the COMPLEMENT MEMBRANE ATTACK COMPLEX. Included are glycoproteins in the various pathways of complement activation (CLASSICAL COMPLEMENT PATHWAY; ALTERNATIVE COMPLEMENT PATHWAY; and LECTIN COMPLEMENT PATHWAY).
Contractile Proteins definition: Proteins which participate in contractile processes. They include MUSCLE PROTEINS as well as those found in other cells and tissues. In the latter, these proteins participate in localized contractile events in the cytoplasm, in motile activity, and in cell aggregation phenomena.
Cytoskeletal Proteins definition: Major constituent of the cytoskeleton found in the cytoplasm of eukaryotic cells. They form a flexible framework for the cell, provide attachment points for organelles and formed bodies, and make communication between parts of the cell possible.
cytoskeletal protein definition: diverse family of structural proteins, including polymerizable globular subunits (actin, tubulin), "motor ATPases" (myosin, dynein), membrane-supporting linkers (spectrin, clathrin), fibrous proteins (keratin, vimentin), and many more.
Cytoskeletal Protein definition: Major constituent of the cytoskeleton found in the cytoplasm of eukaryotic cells. They form a flexible framework for the cell, provide attachment points for organelles and formed bodies, and make communication between parts of the cell possible.
Dietary Proteins definition: Proteins obtained from foods. They are the main source of the ESSENTIAL AMINO ACIDS.
dietary protein definition: proteins obtained from foods; they are the main source of the essential amino acids.
Dietary Protein definition: A macronutrient which forms the major structural components of all the cells of the body. They can function as enzymes, membrane carriers, and hormones.
Egg Proteins definition: Proteins which are found in eggs (OVA) from any species.
egg protein definition: proteins which are found in eggs or ova from any species.
Fungal Proteins definition: Proteins found in any species of fungus.
fungal protein definition: proteins of fungal origin.
glucose transporter definition: transport protein involved in the uptake of glucose.
Glucose Transport Proteins, Facilitative definition: A family of monosaccharide transport proteins characterized by 12 membrane spanning helices. They facilitate passive diffusion of GLUCOSE across the CELL MEMBRANE.
Glutens definition: Prolamins in the endosperm of SEEDS from the Triticeae tribe which includes species of WHEAT; BARLEY; and RYE.
Helminth Proteins definition: Proteins found in any species of helminth.
Hemeproteins definition: Proteins that contain an iron-porphyrin, or heme, prosthetic group resembling that of hemoglobin. (From Lehninger, Principles of Biochemistry, 1982, p480)
hemoprotein definition: conjugated protein containing heme as the prosthetic group.
Heme Protein definition: Proteins that contain a metal-containing cofactor that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. One of the main functions of heme proteins is the retention of molecular oxygen to deliver it for enzymatic reactions. As a result, many heme-containing enzymes are located in the mitochondrion.
hemolysin definition: group of substances, usually of biological origin, that destroy blood cells; they may be antibodies or other immunologic factors, toxins, or enzymes.
Hemolysin Proteins definition: Proteins from BACTERIA and FUNGI that are soluble enough to be secreted to target ERYTHROCYTES and insert into the membrane to form beta-barrel pores. Biosynthesis may be regulated by HEMOLYSIN FACTORS.
High Mobility Group Proteins definition: A family of low-molecular weight, non-histone proteins found in chromatin.
Canonical HMG Protein definition: The High Mobility Group (HMG) proteins were originally isolated from mammalian cells, named according to their electrophoretic mobility in polyacrylamide gels, and were arbitrarily classed as a specific type of non-histone proteins based on the observation that they are ubiquitous to mammalian cells, that they share certain physical properties, and that they are associated with isolated chromatin. Those mammalian proteins considered to be Canonical HMG proteins are now subdivided into 3 superfamilies: the HMGB (formerly HMG-1/-2) family, the HMGN (formerly HMG-14/-17) family, and the HMGA (formerly HMG-I/Y/C) family. Each HMG family has a characteristic functional sequence motif. (www.informatics.jax.org/mgihome/nomen/genefamilies/hmgfamily.shtml)
Histone Deacetylases definition: Deacetylases that remove N-acetyl groups from amino side chains of the amino acids of HISTONES. The enzyme family can be divided into at least three structurally-defined subclasses. Class I and class II deacetylases utilize a zinc-dependent mechanism. The sirtuin histone deacetylases belong to class III and are NAD-dependent enzymes.
Histone Deacetylase definition: Histone acetylation and deacetylation alternately exposes and occludes DNA to transcription factors. Histone deacetylation is catalyzed by the histone deacetylases. There are at least 2 classes of HDACs, class I consisting of proteins homologous to yeast Rpd3 (e.g., HDAC1, HDAC2, and HDAC3) and class II consisting of proteins homologous to yeast Hda1 (e.g., HDAC4 and HDAC6). (from OMIM)
Luminescent Proteins definition: Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.
Proteins definition: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
protein definition: linear polymers of alpha-L-aminoacids ranging in size from a few thousand to over 1 million daltons, capable of oligomerization, with specific functions dictated by aminoacid sequence and encoded genetically.
Protein definition: A group of complex organic macromolecules composed of one or more chains (linear polymers) of alpha-L-amino acids linked by peptide bonds and ranging in size from a few thousand to over 1 million Daltons. Proteins are fundamental genetically encoded components of living cells with specific structures and functions dictated by amino acid sequence.
Recombinant Proteins definition: Proteins prepared by recombinant DNA technology.
recombinant protein definition: peptides or proteins produced by genes which have been artificially inserted into living cells or cell-free expression systems; index with or without RECOMBINANT DNA and the following RTs as needed.
Recombinant Protein definition: Proteins produced by genes or recombinant DNA that has been artificially engineered and inserted into a heterologous host. Recombinant proteins are used extensively by investigators of disease pathways to identify protein targets for potential drug therapies.
Actin Depolymerizing Factors definition: A family of low MOLECULAR WEIGHT actin-binding proteins found throughout eukaryotes. They remodel the actin CYTOSKELETON by severing ACTIN FILAMENTS and increasing the rate of monomer dissociation.
HSP40 Heat-Shock Proteins definition: A family of heat-shock proteins that contain a 70 amino-acid consensus sequence known as the J domain. The J domain of HSP40 heat shock proteins interacts with HSP70 HEAT-SHOCK PROTEINS. HSP40 heat-shock proteins play a role in regulating the ADENOSINE TRIPHOSPHATASES activity of HSP70 heat-shock proteins.
Glycine Plasma Membrane Transport Proteins definition: A family of sodium chloride-dependent neurotransmitter symporters that transport the amino acid GLYCINE. They differ from GLYCINE RECEPTORS, which signal cellular responses to GLYCINE. They are located primarily on the PLASMA MEMBRANE of NEURONS; GLIAL CELLS; EPITHELIAL CELLS; and RED BLOOD CELLS where they remove inhibitory neurotransmitter glycine from the EXTRACELLULAR SPACE.
guanosinetriphosphatase activating protein definition: family of proteins which regulate the activities of Ras proteins.
GTPase-Activating Proteins definition: Proteins that activate the GTPase of specific GTP-BINDING PROTEINS.
Gap definition: An open or empty space in or between things.
GTPase-Activating Protein definition: An extensive family of proteins that stimulates the GTPase activity of GTP-binding ras proteins.
pilin definition: family of globular subunit proteins of bacterial pili.
Fimbriae Proteins definition: Proteins that are structural components of bacterial fimbriae (FIMBRIAE, BACTERIAL) or sex pili (PILI, SEX).
GTP-Binding Proteins definition: Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.
G protein definition: family of small membrane-bound proteins which, in the presence of GTP/GDP, transduce signals from receptor to effector molecules across the membrane; do not use for other guanine nucleotide binding proteins.
G Protein definition: G Proteins are a family of small membrane-bound regulatory proteins that act as GTP/GDP-binding molecular switches controlling a wide range of biological processes including: transmembrane receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP.
14-3-3 Proteins definition: A large family of signal-transducing adaptor proteins present in wide variety of eukaryotes. They are PHOSPHOSERINE and PHOSPHOTHREONINE binding proteins involved in important cellular processes including SIGNAL TRANSDUCTION; CELL CYCLE control; APOPTOSIS; and cellular stress responses. 14-3-3 proteins function by interacting with other signal-transducing proteins and effecting changes in their enzymatic activity and subcellular localization. The name 14-3-3 derives from numerical designations used in the original fractionation patterns of the proteins.
Antifreeze Proteins definition: Proteins that bind to ice and modify the growth of ice crystals. They perform a cryoprotective role in a variety of organisms.
Hu Paraneoplastic Encephalomyelitis Antigens definition: A family of RNA-binding proteins that are homologues of ELAV protein, Drosophila. They were initially identified in humans as the targets of autoantibodies in patients with PARANEOPLASTIC ENCEPHALOMYELITIS. They are thought to regulate GENE EXPRESSION at the post-transcriptional level.
Forkhead Transcription Factors definition: A subclass of winged helix DNA-binding proteins that share homology with their founding member fork head protein, Drosophila.
E2F Transcription Factors definition: A family of basic helix-loop-helix transcription factors that control expression of a variety of GENES involved in CELL CYCLE regulation. E2F transcription factors typically form heterodimeric complexes with TRANSCRIPTION FACTOR DP1 or transcription factor DP2, and they have N-terminal DNA binding and dimerization domains. E2F transcription factors can act as mediators of transcriptional repression or transcriptional activation.
bZIP Protein definition: Bipartite DNA binding protein containing a basic region that directly interacts with DNA, and a leucine zipper that mediates dimerization through contacts with a protein partner.
Basic-Leucine Zipper Transcription Factors definition: A large superfamily of transcription factors that contain a region rich in BASIC AMINO ACID residues followed by a LEUCINE ZIPPER domain.
binding protein definition: general term for class of proteins whose most important function appears to be binding of some ligand for soluability, transport, bioactivity regulation, or other nonenzymatic process; prefer NTs whenever possible.
Ligand Binding Protein definition: General term for proteins that have binding as a major function.
Homeodomain Proteins definition: Proteins encoded by homeobox genes (GENES, HOMEOBOX) that exhibit structural similarity to certain prokaryotic and eukaryotic DNA-binding proteins. Homeodomain proteins are involved in the control of gene expression during morphogenesis and development (GENE EXPRESSION REGULATION, DEVELOPMENTAL).
Homeobox Protein definition: All homeodomain proteins contain the homeodomain, a region of structural similarity present in certain prokaryotic and eukaryotic DNA-binding proteins. Eukaryotic homeodomain proteins are encoded by homeobox genes and typically control gene expression during morphogenesis and development.
Cell Cycle Proteins definition: Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.
cell cycle protein definition: family of proteins that control the cell divisions cycle; includes a wide variety of classes, including cyclin dependent kinases, mitogen activated kinases, cyclins, and phosphoprotein phosphatases as well as their putative substrates such as chromatin associated proteins, cytoskeletal proteins, and transcription factors.
Cell Cycle Protein definition: Proteins involved in the process of cell division. Numerous proteins of different functionality and type are involved in this process.
Cyclin-Dependent Kinases definition: Protein kinases that control cell cycle progression in all eukaryotes and require physical association with CYCLINS to achieve full enzymatic activity. Cyclin-dependent kinases are regulated by phosphorylation and dephosphorylation events.
cyclin dependent kinase definition: nonEC.
Cyclin-Dependent Kinase definition: Cyclin-dependent kinases are eukaryotic, phosphoregulated protein kinases that associate with cyclins to control cell cycle progression.
BHLH Protein definition: Term used to denote the class of sequence-specific DNA-binding proteins that contain the bHLH domain.
BHLH Protein definition: bHLH class proteins are sequence-specific DNA-binding proteins that contain a conserved 50-amino acid HLH domain consisting of two alpha-helices separated by a variable loop sequence, adjacent to a sequence that is highly enriched in basic amino acids. The HLH region mediates protein dimerization, while the basic region mediates sequence-specific DNA binding. Many bHLH proteins recognize a DNA sequence known as the E box. Class A bHLH proteins are ubiquitously expressed, while class B bHLH proteins are expressed in specific cell types. In general, class B proteins preferentially bind to DNA as heterodimers with class A proteins and function as transcriptional activators.
Basic Helix-Loop-Helix Transcription Factors definition: A family of DNA-binding transcription factors that contain a basic HELIX-LOOP-HELIX MOTIF.
Archaeal Proteins definition: Proteins found in any species of archaeon.
Fish Proteins definition: Proteins obtained from species of fish (FISHES).
Algal Proteins definition: Proteins found in any species of algae.
Guanine Nucleotide Dissociation Inhibitors definition: Protein factors that inhibit the dissociation of GDP from GTP-BINDING PROTEINS.
Chimerin Proteins definition: A family of GTPASE-ACTIVATING PROTEINS that are specific for RAC GTP-BINDING PROTEINS.
caveolin definition: only known molecule associated with the striated coat that decorates the inside of caveolar membranes.
Caveolins definition: The main structural proteins of CAVEOLAE. Several distinct genes for caveolins have been identified.
Cyclin-Dependent Kinase Inhibitor definition: Encoded by Cyclin-Dependent Kinase Inhibitor Genes, Cyclin-Dependent Kinase Inhibitor Proteins are a group of low molecular weight proteins that associate with Cyclin/CDK complexes or CDKs alone, inhibiting their activity and regulating the cell cycle. (From OMIM and NCI)
Cyclin-Dependent Kinase Inhibitor Proteins definition: A group of cell cycle proteins that negatively regulate the activity of CYCLIN/CYCLIN-DEPENDENT KINASE complexes. They inhibit CELL CYCLE progression and help control CELL PROLIFERATION following GENOTOXIC STRESS as well as during CELL DIFFERENTIATION.
HMGN Proteins definition: A family of HIGH MOBILITY GROUP PROTEINS that bind to NUCLEOSOMES.
HMGN Family Protein definition: The high mobility group N (HMGN) proteins are a family of nuclear proteins that binds to nucleosomes, changes the architecture of chromatin, and enhances transcription and replication from chromatin templates. They typically contain an NBD (Nucleosome Binding Domain) motif, which anchors these HMG proteins to the nucleosome cores to facilitate HMG-14/-17-dependent changes in higher order chromatin structure. The intracellular organization of the HMGN (previously known as HMG-14/17) proteins is dynamic and is related to both cell-cycle and transcriptional events. These proteins roam the nucleus, perhaps as part of multiprotein complexes, and their target interactions are modulated by posttranslational modifications. Functional studies on HMGN proteins provide insights into the molecular mechanisms by which structural proteins affect DNA-dependent activities in the context of chromatin. (Trends Biochem Sci 2001 Jul;26(7):431-7)
HMGB Proteins definition: A family of sequence-related proteins similar to HMGB1 PROTEIN that contains specific HMG-BOX DOMAINS.
HMGB Family Protein definition: The HMG-Box Family proteins are relatively abundant vertebrate DNA-binding and bending proteins that bind with structure specificity, rather than sequence specificity, and plays an architectural role in the assembly of nucleoprotein complexes. They have two homologous HMG-box DNA-binding domains connected by a short basic linker to an acidic carboxy-terminal tail that differs in length. The length (and possibly sequence) of the acidic tail may be the dominant factor in mediating the differences in properties among themselves and finely tunes the DNA-binding properties of the tandem HMG boxes, to fulfill different cellular roles. The tail is essential for structure-selective DNA-binding of the HMG boxes to DNA minicircles in the presence of equimolar linear DNA, and has little effect on the affinity for this already highly distorted DNA ligand, in contrast to binding to linear and four-way junction DNA. (J Mol Biol 2000 304:135-49)
HMGA Proteins definition: Proteins containing AT-HOOK MOTIFS that are rich in arginine and glycine residues. They bind to the minor grove of AT-rich regions of DNA.
Drosophila Proteins definition: Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.
Drosophila Protein definition: Proteins found in Drosophila.
Amphibian Proteins definition: Proteins obtained from species in the class of AMPHIBIANS.
Avian Proteins definition: Proteins obtained from species of BIRDS.
Arabidopsis Proteins definition: Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.
Capsid Proteins definition: Proteins that form the CAPSID of VIRUSES.
Capsid Protein definition: The outer protective shell of a virus. The structure of the shell is icosahedral with either helical or complex symmetry. Capsid proteins surround and protect the viral nucleic acid core.
Angiogenic Proteins definition: Intercellular signaling peptides and proteins that regulate the proliferation of new blood vessels under normal physiological conditions (ANGIOGENESIS, PHYSIOLOGICAL). Aberrant expression of angiogenic proteins during disease states such as tumorigenesis can also result in PATHOLOGICAL ANGIOGENESIS.
Angiostatic Proteins definition: Proteins that specifically inhibit the growth of new blood vessels (ANGIOGENESIS, PHYSIOLOGIC).
Cullin Proteins definition: A family of structurally related proteins that were originally discovered for their role in cell-cycle regulation in CAENORHABDITIS ELEGANS. They play important roles in regulation of the CELL CYCLE and as components of UBIQUITIN-PROTEIN LIGASES.
amyloid protein definition: extracellular glycoprotein that accumulates in certain pathological conditions, e.g., the paired helical filaments of neuritic plaques in Alzheimer's disease and Down's syndrome; use this term for both the precursor and beta form.
Amyloid Proteins definition: Proteins that form the core of amyloid fibrils. For example, the core of amyloid A is formed from amyloid A protein, also known as serum amyloid A protein or SAA protein.
Armadillo Domain Proteins definition: A family of proteins that contain several 42-amino acid repeat domains and are homologous to the Drosophila armadillo protein. They bind to other proteins through their armadillo domains and play a variety of roles in the CELL including SIGNAL TRANSDUCTION, regulation of DESMOSOME assembly, and CELL ADHESION.
Fanconi Anemia Complementation Group Proteins definition: A diverse group of proteins whose genetic MUTATIONS have been associated with the chromosomal instability syndrome FANCONI ANEMIA. Many of these proteins play important roles in protecting CELLS against OXIDATIVE STRESS.
Frizzled Receptors definition: A family of seven-pass transmembrane cell-surface receptors. They contain an extracellular cysteine-rich domain and are receptors for WNT PROTEINS. Frizzled receptors often couple with HETEROTRIMERIC G PROTEINS and regulate multiple SIGNAL TRANSDUCTION PATHWAYS.
Catenins definition: A family of cytoskeletal proteins that play essential roles in CELL ADHESION at ADHERENS JUNCTIONS by linking CADHERINS to the ACTIN FILAMENTS of the CYTOSKELETON.
Plakins definition: A family of related proteins that associate with cytoskeletal elements and junctional complexes at INTERCELLULAR JUNCTIONS. Plakins share a common plakin domain or a plakin repeat domain.
ADAM Proteins definition: A family of membrane-anchored glycoproteins that contain a disintegrin and metalloprotease domain. They are responsible for the proteolytic cleavage of many transmembrane proteins and the release of their extracellular domain.
Guanylate Cyclase-Activating Proteins definition: Neuronal calcium sensor proteins that regulate the activation of membrane-bound GUANYLATE CYCLASE. They are primarily expressed in the RETINA where they play an important role in PHOTOTRANSDUCTION.
Hedgehog Proteins definition: A family of intercellular signaling proteins that play and important role in regulating the development of many TISSUES and organs. Their name derives from the observation of a hedgehog-like appearance in DROSOPHILA embryos with genetic mutations that block their action.
Human Immunodeficiency Virus Proteins definition: Proteins synthesized by HUMAN IMMUNODEFICIENCY VIRUSES such as the HIV-1 and HIV-2.
SMN Complex Proteins definition: A complex of proteins that assemble the SNRNP CORE PROTEINS into a core structure that surrounds a highly conserved RNA sequence found in SMALL NUCLEAR RNA. They are found localized in the GEMINI OF COILED BODIES and in the CYTOPLASM. The SMN complex is named after the Survival of Motor Neuron Complex Protein 1, which is a critical component of the complex.
CLOCK Proteins definition: Basic helix-loop-helix (bHLH) domain-containing proteins that contain intrinsic HISTONE ACETYLTRANSFERASE activity and play important roles in CIRCADIAN RHYTHM regulation. Clock proteins combine with Arntl proteins to form heterodimeric transcription factors that are specific for E-BOX ELEMENTS and stimulate the transcription of several E-box genes that are involved in cyclical regulation. This transcriptional activation also sets into motion a time-dependent feedback loop which in turn down-regulates the expression of clock proteins.
Cryptochromes definition: Flavoproteins that function as circadian rhythm signaling proteins in ANIMALS and as blue-light photoreceptors in PLANTS. They are structurally-related to DNA PHOTOLYASES and it is believed that both classes of proteins may have originated from an earlier protein that played a role in protecting primitive organisms from the cyclical exposure to UV LIGHT.
Co-Repressor Proteins definition: A subclass of repressor proteins that do not directly bind DNA. Instead, co-repressors generally act via their interaction with DNA-BINDING PROTEINS such as a TRANSCRIPTIONAL SILENCING FACTORS or NUCLEAR RECEPTORS.
Claudins definition: A large family of transmembrane proteins found in TIGHT JUNCTIONS. They take part in the formation of paracellular barriers and pores that regulate paracellular permeability.