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Integrin-Binding Sialoprotein: A highly glycosylated and sulfated phosphoprotein that is found almost exclusively in mineralized connective tissues. It is an extracellular matrix protein that binds to hydroxyapatite through polyglutamic acid sequences and mediates cell attachment through an RGD sequence.Integrins: A family of transmembrane glycoproteins (MEMBRANE GLYCOPROTEINS) consisting of noncovalent heterodimers. They interact with a wide variety of ligands including EXTRACELLULAR MATRIX PROTEINS; COMPLEMENT, and other cells, while their intracellular domains interact with the CYTOSKELETON. The integrins consist of at least three identified families: the cytoadhesin receptors(RECEPTORS, CYTOADHESIN), the leukocyte adhesion receptors (RECEPTORS, LEUKOCYTE ADHESION), and the VERY LATE ANTIGEN RECEPTORS. Each family contains a common beta-subunit (INTEGRIN BETA CHAINS) combined with one or more distinct alpha-subunits (INTEGRIN ALPHA CHAINS). These receptors participate in cell-matrix and cell-cell adhesion in many physiologically important processes, including embryological development; HEMOSTASIS; THROMBOSIS; WOUND HEALING; immune and nonimmune defense mechanisms; and oncogenic transformation.Sialoglycoproteins: Glycoproteins which contain sialic acid as one of their carbohydrates. They are often found on or in the cell or tissue membranes and participate in a variety of biological activities.Integrin alphaVbeta3: An integrin that binds to a variety of plasma and extracellular matrix proteins containing the conserved RGD amino acid sequence and modulates cell adhesion. Integrin alphavbeta3 is highly expressed in OSTEOCLASTS where it may play role in BONE RESORPTION. It is also abundant in vascular smooth muscle and endothelial cells, and in some tumor cells, where it is involved in angiogenesis and cell migration. Although often referred to as the vitronectin receptor there is more than one receptor for vitronectin (RECEPTORS, VITRONECTIN).Integrin beta3: An integrin beta subunit of approximately 85-kDa in size which has been found in INTEGRIN ALPHAIIB-containing and INTEGRIN ALPHAV-containing heterodimers. Integrin beta3 occurs as three alternatively spliced isoforms, designated beta3A-C.Cell Adhesion: Adherence of cells to surfaces or to other cells.Integrin beta Chains: Integrin beta chains combine with integrin alpha chains to form heterodimeric cell surface receptors. Integrins have traditionally been classified into functional groups based on the identity of one of three beta chains present in the heterodimer. The beta chain is necessary and sufficient for integrin-dependent signaling. Its short cytoplasmic tail contains sequences critical for inside-out signaling.Integrin alpha5beta1: An integrin found in FIBROBLASTS; PLATELETS; MONOCYTES, and LYMPHOCYTES. Integrin alpha5beta1 is the classical receptor for FIBRONECTIN, but it also functions as a receptor for LAMININ and several other EXTRACELLULAR MATRIX PROTEINS.Talin: A 235-kDa cytoplasmic protein that is also found in platelets. It has been localized to regions of cell-substrate adhesion. It binds to INTEGRINS; VINCULIN; and ACTINS and appears to participate in generating a transmembrane connection between the extracellular matrix and the cytoskeleton.Integrin alpha3beta1: Cell surface receptor for LAMININ, epiligrin, FIBRONECTINS, entactin, and COLLAGEN. Integrin alpha3beta1 is the major integrin present in EPITHELIAL CELLS, where it plays a role in the assembly of BASEMENT MEMBRANE as well as in cell migration, and may regulate the functions of other integrins. Two alternatively spliced isoforms of the alpha subunit (INTEGRIN ALPHA3), are differentially expressed in different cell types.Osteopontin: A negatively-charged extracellular matrix protein that plays a role in the regulation of BONE metabolism and a variety of other biological functions. Cell signaling by osteopontin may occur through a cell adhesion sequence that recognizes INTEGRIN ALPHA-V BETA-3.Antigens, CD29: Integrin beta-1 chains which are expressed as heterodimers that are noncovalently associated with specific alpha-chains of the CD49 family (CD49a-f). CD29 is expressed on resting and activated leukocytes and is a marker for all of the very late activation antigens on cells. (from: Barclay et al., The Leukocyte Antigen FactsBook, 1993, p164)Oligopeptides: Peptides composed of between two and twelve amino acids.Integrin alpha4: An integrin alpha subunit that is unique in that it does not contain an I domain, and its proteolytic cleavage site is near the middle of the extracellular portion of the polypeptide rather than close to the membrane as in other integrin alpha subunits.Integrin alpha2beta1: An integrin found on fibroblasts, platelets, endothelial and epithelial cells, and lymphocytes where it functions as a receptor for COLLAGEN and LAMININ. Although originally referred to as the collagen receptor, it is one of several receptors for collagen. Ligand binding to integrin alpha2beta1 triggers a cascade of intracellular signaling, including activation of p38 MAP kinase.Fibronectins: Glycoproteins found on the surfaces of cells, particularly in fibrillar structures. The proteins are lost or reduced when these cells undergo viral or chemical transformation. They are highly susceptible to proteolysis and are substrates for activated blood coagulation factor VIII. The forms present in plasma are called cold-insoluble globulins.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Receptors, Vitronectin: Receptors such as INTEGRIN ALPHAVBETA3 that bind VITRONECTIN with high affinity and play a role in cell migration. They also bind FIBRINOGEN; VON WILLEBRAND FACTOR; osteopontin; and THROMBOSPONDINS.Integrin alpha6beta1: A cell surface receptor mediating cell adhesion to the EXTRACELLULAR MATRIX and to other cells via binding to LAMININ. It is involved in cell migration, embryonic development, leukocyte activation and tumor cell invasiveness. Integrin alpha6beta1 is the major laminin receptor on PLATELETS; LEUKOCYTES; and many EPITHELIAL CELLS, and ligand binding may activate a number of signal transduction pathways. Alternative splicing of the cytoplasmic domain of the alpha6 subunit (INTEGRIN ALPHA6) results in the formation of A and B isoforms of the heterodimer, which are expressed in a tissue-specific manner.Extracellular Matrix Proteins: Macromolecular organic compounds that contain carbon, hydrogen, oxygen, nitrogen, and usually, sulfur. These macromolecules (proteins) form an intricate meshwork in which cells are embedded to construct tissues. Variations in the relative types of macromolecules and their organization determine the type of extracellular matrix, each adapted to the functional requirements of the tissue. The two main classes of macromolecules that form the extracellular matrix are: glycosaminoglycans, usually linked to proteins (proteoglycans), and fibrous proteins (e.g., COLLAGEN; ELASTIN; FIBRONECTINS; and LAMININ).Integrin alpha5: This integrin alpha subunit combines with INTEGRIN BETA1 to form a receptor (INTEGRIN ALPHA5BETA1) that binds FIBRONECTIN and LAMININ. It undergoes posttranslational cleavage into a heavy and a light chain that are connected by disulfide bonds.Integrin alpha6: An integrin alpha subunit that primarily associates with INTEGRIN BETA1 or INTEGRIN BETA4 to form laminin-binding heterodimers. Integrin alpha6 has two alternatively spliced isoforms: integrin alpha6A and integrin alpha6B, which differ in their cytoplasmic domains and are regulated in a tissue-specific and developmental stage-specific manner.Integrin alpha Chains: The alpha subunits of integrin heterodimers (INTEGRINS), which mediate ligand specificity. There are approximately 18 different alpha chains, exhibiting great sequence diversity; several chains are also spliced into alternative isoforms. They possess a long extracellular portion (1200 amino acids) containing a MIDAS (metal ion-dependent adhesion site) motif, and seven 60-amino acid tandem repeats, the last 4 of which form EF HAND MOTIFS. The intracellular portion is short with the exception of INTEGRIN ALPHA4.Integrin beta4: Also known as CD104 antigen, this protein is distinguished from other beta integrins by its relatively long cytoplasmic domain (approximately 1000 amino acids vs. approximately 50). Five alternatively spliced isoforms have been described.Integrin alpha2: An integrin alpha subunit that primarily combines with INTEGRIN BETA1 to form the INTEGRIN ALPHA2BETA1 heterodimer. It contains a domain which has homology to collagen-binding domains found in von Willebrand factor.Integrin alphaV: An alpha integrin with a molecular weight of 160-kDa that is found in a variety of cell types. It undergoes posttranslational cleavage into a heavy and a light chain that are connected by disulfide bonds. Integrin alphaV can combine with several different beta subunits to form heterodimers that generally bind to RGD sequence-containing extracellular matrix proteins.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Integrin alpha6beta4: This intrgrin is a key component of HEMIDESMOSOMES and is required for their formation and maintenance in epithelial cells. Integrin alpha6beta4 is also found on thymocytes, fibroblasts, and Schwann cells, where it functions as a laminin receptor (RECEPTORS, LAMININ) and is involved in wound healing, cell migration, and tumor invasiveness.Receptors, Fibronectin: Specific cell surface receptors which bind to FIBRONECTINS. Studies have shown that these receptors function in certain types of adhesive contact as well as playing a major role in matrix assembly. These receptors include the traditional fibronectin receptor, also called INTEGRIN ALPHA5BETA1 and several other integrins.Calcification, Physiologic: Process by which organic tissue becomes hardened by the physiologic deposit of calcium salts.OdontoblastsIntegrin alpha1beta1: Integrin alpha1beta1 functions as a receptor for LAMININ and COLLAGEN. It is widely expressed during development, but in the adult is the predominant laminin receptor (RECEPTORS, LAMININ) in mature SMOOTH MUSCLE CELLS, where it is important for maintenance of the differentiated phenotype of these cells. Integrin alpha1beta1 is also found in LYMPHOCYTES and microvascular endothelial cells, and may play a role in angiogenesis. In SCHWANN CELLS and neural crest cells, it is involved in cell migration. Integrin alpha1beta1 is also known as VLA-1 and CD49a-CD29.Integrin alpha3: An integrin alpha subunit that occurs as alternatively spliced isoforms. The isoforms are differentially expressed in specific cell types and at specific developmental stages. Integrin alpha3 combines with INTEGRIN BETA1 to form INTEGRIN ALPHA3BETA1 which is a heterodimer found primarily in epithelial cells.Extracellular Matrix: A meshwork-like substance found within the extracellular space and in association with the basement membrane of the cell surface. It promotes cellular proliferation and provides a supporting structure to which cells or cell lysates in culture dishes adhere.Osteoblasts: Bone-forming cells which secrete an EXTRACELLULAR MATRIX. HYDROXYAPATITE crystals are then deposited into the matrix to form bone.Laminin: Large, noncollagenous glycoprotein with antigenic properties. It is localized in the basement membrane lamina lucida and functions to bind epithelial cells to the basement membrane. Evidence suggests that the protein plays a role in tumor invasion.Integrin alpha1: An integrin alpha subunit that binds COLLAGEN and LAMININ though its I domain. It combines with INTEGRIN BETA1 to form the heterodimer INTEGRIN ALPHA1BETA1.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Dental Cementum: The bonelike rigid connective tissue covering the root of a tooth from the cementoenamel junction to the apex and lining the apex of the root canal, also assisting in tooth support by serving as attachment structures for the periodontal ligament. (Jablonski, Dictionary of Dentistry, 1992)Disintegrins: A family of polypeptides purified from snake venoms, which contain the arginine-glycine-aspartic acid (RGD) sequence. The RGD tripeptide binds to integrin receptors and thus competitively inhibits normal integrin-ligand interactions. Disintegrins thus block adhesive functions and act as platelet aggregation inhibitors.Osteogenesis: The process of bone formation. Histogenesis of bone including ossification.Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.Antigens, CD18: Cell-surface glycoprotein beta-chains that are non-covalently linked to specific alpha-chains of the CD11 family of leukocyte-adhesion molecules (RECEPTORS, LEUKOCYTE-ADHESION). A defect in the gene encoding CD18 causes LEUKOCYTE-ADHESION DEFICIENCY SYNDROME.Vinculin: A cytoskeletal protein associated with cell-cell and cell-matrix interactions. The amino acid sequence of human vinculin has been determined. The protein consists of 1066 amino acid residues and its gene has been assigned to chromosome 10.Focal Adhesions: An anchoring junction of the cell to a non-cellular substrate. It is composed of a specialized area of the plasma membrane where bundles of the ACTIN CYTOSKELETON terminate and attach to the transmembrane linkers, INTEGRINS, which in turn attach through their extracellular domains to EXTRACELLULAR MATRIX PROTEINS.Cell Movement: The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.Osteocalcin: Vitamin K-dependent calcium-binding protein synthesized by OSTEOBLASTS and found primarily in BONES. Serum osteocalcin measurements provide a noninvasive specific marker of bone metabolism. The protein contains three residues of the amino acid gamma-carboxyglutamic acid (Gla), which, in the presence of CALCIUM, promotes binding to HYDROXYAPATITE and subsequent accumulation in BONE MATRIX.Vitronectin: A blood plasma glycoprotein that mediates cell adhesion and interacts with proteins of the complement, coagulation, and fibrinolytic cascade. (From Segen, Dictionary of Modern Medicine, 1992)Bone Matrix: Extracellular substance of bone tissue consisting of COLLAGEN fibers, ground substance, and inorganic crystalline minerals and salts.Dentinogenesis: The formation of dentin. Dentin first appears in the layer between the ameloblasts and odontoblasts and becomes calcified immediately. Formation progresses from the tip of the papilla over its slope to form a calcified cap becoming thicker by the apposition of new layers pulpward. A layer of uncalcified dentin intervenes between the calcified tissue and the odontoblast and its processes. (From Jablonski, Dictionary of Dentistry, 1992)Bone and Bones: A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principle cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Dentin: The hard portion of the tooth surrounding the pulp, covered by enamel on the crown and cementum on the root, which is harder and denser than bone but softer than enamel, and is thus readily abraded when left unprotected. (From Jablonski, Dictionary of Dentistry, 1992)Cell Adhesion Molecules: Surface ligands, usually glycoproteins, that mediate cell-to-cell adhesion. Their functions include the assembly and interconnection of various vertebrate systems, as well as maintenance of tissue integration, wound healing, morphogenic movements, cellular migrations, and metastasis.Filamins: A family of crosslinking filament proteins encoded by distinct FLN genes. Filamins are involved in cell adhesion, spreading, and migration, acting as scaffolds for over 90 binding partners including channels, receptors, intracellular signaling molecules and transcription factors. Due to the range of molecular interactions, mutations in FLN genes result in anomalies with moderate to lethal consequences.Core Binding Factor Alpha 1 Subunit: A transcription factor that dimerizes with CORE BINDING FACTOR BETA SUBUNIT to form core binding factor. It contains a highly conserved DNA-binding domain known as the runt domain and is involved in genetic regulation of skeletal development and CELL DIFFERENTIATION.Integrin alpha4beta1: Integrin alpha4beta1 is a FIBRONECTIN and VCAM-1 receptor present on LYMPHOCYTES; MONOCYTES; EOSINOPHILS; NK CELLS and thymocytes. It is involved in both cell-cell and cell- EXTRACELLULAR MATRIX adhesion and plays a role in INFLAMMATION, hematopoietic cell homing and immune function, and has been implicated in skeletal MYOGENESIS; NEURAL CREST migration and proliferation, lymphocyte maturation and morphogenesis of the PLACENTA and HEART.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Ligands: A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)Yersinia pseudotuberculosis: A human and animal pathogen causing mesenteric lymphadenitis, diarrhea, and bacteremia.Collagen: A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).Recombinant Proteins: Proteins prepared by recombinant DNA technology.Cementogenesis: The formation of DENTAL CEMENTUM, a bone-like material that covers the root of the tooth.Antigens, CD: Differentiation antigens residing on mammalian leukocytes. CD stands for cluster of differentiation, which refers to groups of monoclonal antibodies that show similar reactivity with certain subpopulations of antigens of a particular lineage or differentiation stage. The subpopulations of antigens are also known by the same CD designation.CHO Cells: CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.Alkaline Phosphatase: An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.1.Periodontal Ligament: The fibrous CONNECTIVE TISSUE surrounding the TOOTH ROOT, separating it from and attaching it to the alveolar bone (ALVEOLAR PROCESS).PhosphoproteinsCricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Tooth Calcification: The process whereby calcium salts are deposited in the dental enamel. The process is normal in the development of bones and teeth. (Boucher's Clinical Dental Terminology, 4th ed, p43)Cell Line, Tumor: A cell line derived from cultured tumor cells.Cytoskeleton: The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.Amino Acid Motifs: Commonly observed structural components of proteins formed by simple combinations of adjacent secondary structures. A commonly observed structure may be composed of a CONSERVED SEQUENCE which can be represented by a CONSENSUS SEQUENCE.Peptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.Durapatite: The mineral component of bones and teeth; it has been used therapeutically as a prosthetic aid and in the prevention and treatment of osteoporosis.Vascular Cell Adhesion Molecule-1: Cytokine-induced cell adhesion molecule present on activated endothelial cells, tissue macrophages, dendritic cells, bone marrow fibroblasts, myoblasts, and myotubes. It is important for the recruitment of leukocytes to sites of inflammation. (From Pigott & Power, The Adhesion Molecule FactsBook, 1993, p154)Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Dental Pulp: A richly vascularized and innervated connective tissue of mesodermal origin, contained in the central cavity of a tooth and delimited by the dentin, and having formative, nutritive, sensory, and protective functions. (Jablonski, Dictionary of Dentistry, 1992)Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Actins: Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.Receptors, Lymphocyte Homing: Cell surface glycoproteins on lymphocytes and other leukocytes that mediate adhesion to specialized blood vessels called high endothelial venules. Several different classes of lymphocyte homing receptors have been identified, and they appear to target different surface molecules (addressins) on high endothelial venules in different tissues. The adhesion plays a crucial role in the trafficking of lymphocytes.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Transfection: The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Cricetulus: A genus of the family Muridae consisting of eleven species. C. migratorius, the grey or Armenian hamster, and C. griseus, the Chinese hamster, are the two species used in biomedical research.Platelet Glycoprotein GPIIb-IIIa Complex: Platelet membrane glycoprotein complex important for platelet adhesion and aggregation. It is an integrin complex containing INTEGRIN ALPHAIIB and INTEGRIN BETA3 which recognizes the arginine-glycine-aspartic acid (RGD) sequence present on several adhesive proteins. As such, it is a receptor for FIBRINOGEN; VON WILLEBRAND FACTOR; FIBRONECTIN; VITRONECTIN; and THROMBOSPONDINS. A deficiency of GPIIb-IIIa results in GLANZMANN THROMBASTHENIA.Molar: The most posterior teeth on either side of the jaw, totaling eight in the deciduous dentition (2 on each side, upper and lower), and usually 12 in the permanent dentition (three on each side, upper and lower). They are grinding teeth, having large crowns and broad chewing surfaces. (Jablonski, Dictionary of Dentistry, 1992, p821)Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Receptors, Collagen: Collagen receptors are cell surface receptors that modulate signal transduction between cells and the EXTRACELLULAR MATRIX. They are found in many cell types and are involved in the maintenance and regulation of cell shape and behavior, including PLATELET ACTIVATION and aggregation, through many different signaling pathways and differences in their affinities for collagen isoforms. Collagen receptors include discoidin domain receptors, INTEGRINS, and glycoprotein VI.Dental Papilla: Mesodermal tissue enclosed in the invaginated portion of the epithelial enamel organ and giving rise to the dentin and pulp.Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).Tumor Cells, Cultured: Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.Microfilament Proteins: Monomeric subunits of primarily globular ACTIN and found in the cytoplasmic matrix of almost all cells. They are often associated with microtubules and may play a role in cytoskeletal function and/or mediate movement of the cell or the organelles within the cell.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Collagen Type I: The most common form of fibrillar collagen. It is a major constituent of bone (BONE AND BONES) and SKIN and consists of a heterotrimer of two alpha1(I) and one alpha2(I) chains.Stress, Mechanical: A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.Cytoskeletal Proteins: 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.Endothelial Cells: Highly specialized EPITHELIAL CELLS that line the HEART; BLOOD VESSELS; and lymph vessels, forming the ENDOTHELIUM. They are polygonal in shape and joined together by TIGHT JUNCTIONS. The tight junctions allow for variable permeability to specific macromolecules that are transported across the endothelial layer.Tooth: One of a set of bone-like structures in the mouth used for biting and chewing.Endothelium, Vascular: Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.Fibroblasts: Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.Osteonectin: Non-collagenous, calcium-binding glycoprotein of developing bone. It links collagen to mineral in the bone matrix. In the synonym SPARC glycoprotein, the acronym stands for Secreted Protein, Acidic and Rich in Cysteine.Dental Sac: Dense fibrous layer formed from mesodermal tissue that surrounds the epithelial enamel organ. The cells eventually migrate to the external surface of the newly formed root dentin and give rise to the cementoblasts that deposit cementum on the developing root, fibroblasts of the developing periodontal ligament, and osteoblasts of the developing alveolar bone.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Dental Pulp Exposure: The result of pathological changes in the hard tissue of a tooth caused by carious lesions, mechanical factors, or trauma, which render the pulp susceptible to bacterial invasion from the external environment.Periodontium: The structures surrounding and supporting the tooth. Periodontium includes the gum (GINGIVA), the alveolar bone (ALVEOLAR PROCESS), the DENTAL CEMENTUM, and the PERIODONTAL LIGAMENT.Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.Recombinant Fusion Proteins: Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.Amelogenesis: The elaboration of dental enamel by ameloblasts, beginning with its participation in the formation of the dentino-enamel junction to the production of the matrix for the enamel prisms and interprismatic substance. (Jablonski, Dictionary of Dentistry, 1992).RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Hydroxyapatites: A group of compounds with the general formula M10(PO4)6(OH)2, where M is barium, strontium, or calcium. The compounds are the principal mineral in phosphorite deposits, biological tissue, human bones, and teeth. They are also used as an anticaking agent and polymer catalysts. (Grant & Hackh's Chemical Dictionary, 5th ed)Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Bone Regeneration: Renewal or repair of lost bone tissue. It excludes BONY CALLUS formed after BONE FRACTURES but not yet replaced by hard bone.Focal Adhesion Protein-Tyrosine Kinases: A family of non-receptor, PROLINE-rich protein-tyrosine kinases.Fos-Related Antigen-2: A basic-leucine zipper transcription factor that is closely related to C-FOS PROTEINS. It forms heterodimeric complexes with C-JUN PROTEINS to regulate GENE transcription.OsteomyelitisTooth Root: The part of a tooth from the neck to the apex, embedded in the alveolar process and covered with cementum. A root may be single or divided into several branches, usually identified by their relative position, e.g., lingual root or buccal root. Single-rooted teeth include mandibular first and second premolars and the maxillary second premolar teeth. The maxillary first premolar has two roots in most cases. Maxillary molars have three roots. (Jablonski, Dictionary of Dentistry, 1992, p690)Mutagenesis, Site-Directed: Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.Core Binding Factor alpha Subunits: A family of transcription factors that bind to the cofactor CORE BINDING FACTOR BETA SUBUNIT to form core binding factor. Family members contain a highly conserved DNA-binding domain known as the runt domain. They can act as both activators and repressors of expression of GENES involved in CELL DIFFERENTIATION and CELL CYCLE progression.Incisor: Any of the eight frontal teeth (four maxillary and four mandibular) having a sharp incisal edge for cutting food and a single root, which occurs in man both as a deciduous and a permanent tooth. (Jablonski, Dictionary of Dentistry, 1992, p820)Macrophage-1 Antigen: An adhesion-promoting leukocyte surface membrane heterodimer. The alpha subunit consists of the CD11b ANTIGEN and the beta subunit the CD18 ANTIGEN. The antigen, which is an integrin, functions both as a receptor for complement 3 and in cell-cell and cell-substrate adhesive interactions.Skull: The SKELETON of the HEAD including the FACIAL BONES and the bones enclosing the BRAIN.Apatites: A group of phosphate minerals that includes ten mineral species and has the general formula X5(YO4)3Z, where X is usually calcium or lead, Y is phosphorus or arsenic, and Z is chlorine, fluorine, or OH-. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Bone Morphogenetic Protein 2: A potent osteoinductive protein that plays a critical role in the differentiation of osteoprogenitor cells into OSTEOBLASTS.Integrin alphaXbeta2: A major adhesion-associated heterodimer molecule expressed by MONOCYTES; GRANULOCYTES; NK CELLS; and some LYMPHOCYTES. The alpha subunit is the CD11C ANTIGEN, a surface antigen expressed on some myeloid cells. The beta subunit is the CD18 ANTIGEN.Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Proteoglycans: Glycoproteins which have a very high polysaccharide content.Protein PrecursorsFocal Adhesion Kinase 1: A non-receptor protein tyrosine kinase that is localized to FOCAL ADHESIONS and is a central component of integrin-mediated SIGNAL TRANSDUCTION PATHWAYS. Focal adhesion kinase 1 interacts with PAXILLIN and undergoes PHOSPHORYLATION in response to adhesion of cell surface integrins to the EXTRACELLULAR MATRIX. Phosphorylated p125FAK protein binds to a variety of SH2 DOMAIN and SH3 DOMAIN containing proteins and helps regulate CELL ADHESION and CELL MIGRATION.Receptors, Laminin: Glycoprotein molecules on the surface of cells that react with or bind to laminin whose function allows the binding of epithelial cells to the basement membrane. The molecular weight of this high-affinity receptor is 67 kD.Osteocytes: Mature osteoblasts that have become embedded in the BONE MATRIX. They occupy a small cavity, called lacuna, in the matrix and are connected to adjacent osteocytes via protoplasmic projections called canaliculi.Lymphocyte Function-Associated Antigen-1: An integrin heterodimer widely expressed on cells of hematopoietic origin. CD11A ANTIGEN comprises the alpha chain and the CD18 antigen (ANTIGENS, CD18) the beta chain. Lymphocyte function-associated antigen-1 is a major receptor of T-CELLS; B-CELLS; and GRANULOCYTES. It mediates the leukocyte adhesion reactions underlying cytolytic conjugate formation, helper T-cell interactions, and antibody-dependent killing by NATURAL KILLER CELLS and granulocytes. Intracellular adhesion molecule-1 has been defined as a ligand for lymphocyte function-associated antigen-1.Matrilin Proteins: PROTEOGLYCANS-associated proteins that are major components of EXTRACELLULAR MATRIX of various tissues including CARTILAGE; and INTERVERTEBRAL DISC structures. They bind COLLAGEN fibers and contain protein domains that enable oligomer formation and interaction with other extracellular matrix proteins such as CARTILAGE OLIGOMERIC MATRIX PROTEIN.Promoter Regions, Genetic: DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Osteoclasts: A large multinuclear cell associated with the BONE RESORPTION. An odontoclast, also called cementoclast, is cytomorphologically the same as an osteoclast and is involved in CEMENTUM resorption.Chondrosarcoma: A slowly growing malignant neoplasm derived from cartilage cells, occurring most frequently in pelvic bones or near the ends of long bones, in middle-aged and old people. Most chondrosarcomas arise de novo, but some may develop in a preexisting benign cartilaginous lesion or in patients with ENCHONDROMATOSIS. (Stedman, 25th ed)Alveolar Process: The thickest and spongiest part of the maxilla and mandible hollowed out into deep cavities for the teeth.Sialic Acids: A group of naturally occurring N-and O-acyl derivatives of the deoxyamino sugar neuraminic acid. They are ubiquitously distributed in many tissues.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Cell Shape: The quality of surface form or outline of CELLS.Cartilage Oligomeric Matrix Protein: Major component of chondrocyte EXTRACELLULAR MATRIX of various tissues including bone, tendon, ligament, SYNOVIUM and blood vessels. It binds MATRILIN PROTEINS and is associated with development of cartilage and bone.Periosteum: Thin outer membrane that surrounds a bone. It contains CONNECTIVE TISSUE, CAPILLARIES, nerves, and a number of cell types.Fibrinogen: Plasma glycoprotein clotted by thrombin, composed of a dimer of three non-identical pairs of polypeptide chains (alpha, beta, gamma) held together by disulfide bonds. Fibrinogen clotting is a sol-gel change involving complex molecular arrangements: whereas fibrinogen is cleaved by thrombin to form polypeptides A and B, the proteolytic action of other enzymes yields different fibrinogen degradation products.Dental Enamel: A hard thin translucent layer of calcified substance which envelops and protects the dentin of the crown of the tooth. It is the hardest substance in the body and is almost entirely composed of calcium salts. Under the microscope, it is composed of thin rods (enamel prisms) held together by cementing substance, and surrounded by an enamel sheath. (From Jablonski, Dictionary of Dentistry, 1992, p286)Dental Enamel Proteins: The proteins that are part of the dental enamel matrix.Paxillin: Paxillin is a signal transducing adaptor protein that localizes to FOCAL ADHESIONS via its four LIM domains. It undergoes PHOSPHORYLATION in response to integrin-mediated CELL ADHESION, and interacts with a variety of proteins including VINCULIN; FOCAL ADHESION KINASE; PROTO-ONCOGENE PROTEIN PP60(C-SRC); and PROTO-ONCOGENE PROTEIN C-CRK.Platelet Membrane Glycoprotein IIb: Platelet membrane glycoprotein IIb is an integrin alpha subunit that heterodimerizes with INTEGRIN BETA3 to form PLATELET GLYCOPROTEIN GPIIB-IIIA COMPLEX. It is synthesized as a single polypeptide chain which is then postranslationally cleaved and processed into two disulfide-linked subunits of approximately 18 and 110 kDa in size.Cell Proliferation: All of the processes involved in increasing CELL NUMBER including CELL DIVISION.Mesenchymal Stromal Cells: Bone-marrow-derived, non-hematopoietic cells that support HEMATOPOETIC STEM CELLS. They have also been isolated from other organs and tissues such as UMBILICAL CORD BLOOD, umbilical vein subendothelium, and WHARTON JELLY. These cells are considered to be a source of multipotent stem cells because they include subpopulations of mesenchymal stem cells.Tissue Scaffolds: Cell growth support structures composed of BIOCOMPATIBLE MATERIALS. They are specially designed solid support matrices for cell attachment in TISSUE ENGINEERING and GUIDED TISSUE REGENERATION uses.Bone Neoplasms: Tumors or cancer located in bone tissue or specific BONES.Osteosarcoma: A sarcoma originating in bone-forming cells, affecting the ends of long bones. It is the most common and most malignant of sarcomas of the bones, and occurs chiefly among 10- to 25-year-old youths. (From Stedman, 25th ed)Platelet Membrane Glycoproteins: Surface glycoproteins on platelets which have a key role in hemostasis and thrombosis such as platelet adhesion and aggregation. Many of these are receptors.Bone Resorption: Bone loss due to osteoclastic activity.Cell Culture Techniques: Methods for maintaining or growing CELLS in vitro.Antigens, CD151: Tetraspanin proteins found associated with LAMININ-binding INTEGRINS. The CD151 antigens may play a role in the regulation of CELL MOTILITY.Receptors, Very Late Antigen: Members of the integrin family appearing late after T-cell activation. They are a family of proteins initially identified at the surface of stimulated T-cells, but now identified on a variety of cell types. At least six VLA antigens have been identified as heterodimeric adhesion receptors consisting of a single common beta-subunit and different alpha-subunits.N-Acetylneuraminic Acid: An N-acyl derivative of neuraminic acid. N-acetylneuraminic acid occurs in many polysaccharides, glycoproteins, and glycolipids in animals and bacteria. (From Dorland, 28th ed, p1518)Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Blood Platelets: Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Up-Regulation: A positive regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.Flow Cytometry: Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.Sulfur Radioisotopes: Unstable isotopes of sulfur that decay or disintegrate spontaneously emitting radiation. S 29-31, 35, 37, and 38 are radioactive sulfur isotopes.Chromatography, Ion Exchange: Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.