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TLN1
Talin-1 is a protein that in humans is encoded by the ''TLN1'' gene. Talin-1 is ubiquitously expressed, and is localized to costamere structures in cardiac and skeletal muscle cells, and to focal adhesions in smooth muscle and non-muscle cells. Talin-1 functions to mediate cell-cell adhesion via the linkage of integrins to the actin cytoskeleton and in the activation of integrins. Altered expression of talin-1 has been observed in patients with heart failure, however no mutations in ''TLN1'' have been linked with specific diseases. Structure Human talin-1 is 270.0 kDa molecular weight and 2541 amino acids. The N-terminal region of talin-1 is ~50 kDa in size and homologous to members of the ERM protein family which have a globular FERM domain (residues 86-400) that links the actin cytoskeleton to adhesion proteins. In addition to F-actin, the N-terminal region of talin-1 binds layilin, β1- and β3-integrin, and focal adhesion kinase. Talin-1 N-terminal region also binds ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TLN2
Talin 2 is a protein in humans that is encoded by the TLN2 gene. It belongs to the talin protein family. This gene encodes a protein related to talin 1, a cytoskeletal protein that plays a significant role in the assembly of actin filaments. Talin-2 is expressed at high levels in cardiac muscle and functions to provide linkages between the extracellular matrix and actin cytoskeleton at costamere structures to transduce force laterally. Structure Human talin-2 is 271.4 kDa and 2542 amino acids in length. The size of talin-2 protein is similar to talin-1, and is relatively similar (74% identity, 86% similarity); the size of the talin-2 gene (200 kb) is however much larger than that of talin-1 (30 kb), due to differences in intron sizes. Talin-2 mRNA is expressed in multiple tissues, including cardiac muscle, mouse embryonic stem cells, brain, lung, skeletal muscle, kidney and testis; however expression is highest in cardiac muscle. A detailed analysis of the ''TLN2'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ITGB3
Integrin beta-3 (β3) or CD61 is a protein that in humans is encoded by the ''ITGB3'' gene. CD61 is a cluster of differentiation found on thrombocytes. Structure and function The ITGB3 protein product is the integrin beta chain beta 3. Integrins are integral cell-surface proteins composed of an alpha chain and a beta chain. A given chain may combine with multiple partners resulting in different integrins. Integrin beta 3 is found along with the alpha IIb chain in platelets. Integrins are known to participate in cell adhesion as well as cell-surface-mediated signaling. Role in endometriosis Defectively expressed β3 integrin subunit has been correlated with presence of endometriosis, and has been suggested as a putative marker of this condition. Interactions CD61 has been shown to interact with PTK2, ITGB3BP, TLN1 and CIB1. See also * Glycoprotein IIb/IIIa In medicine, glycoprotein IIb/IIIa (GPIIb/IIIa, also known as integrin αIIbβ3) is an integrin complex found on platelet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PTK2
PTK2 protein tyrosine kinase 2 (PTK2), also known as focal adhesion kinase (FAK), is a protein that, in humans, is encoded by the ''PTK2'' gene. PTK2 is a focal adhesion-associated protein kinase involved in cellular adhesion (how cells stick to each other and their surroundings) and spreading processes (how cells move around). It has been shown that when FAK was blocked, breast cancer cells became less metastatic due to decreased mobility. Function The PTK2 gene encodes a cytosolic protein tyrosine kinase that is found concentrated in the focal adhesions that form among cells attaching to extracellular matrix constituents. The encoded protein is a member of the FAK subfamily of protein tyrosine kinases that included PYK2, but lacks significant sequence similarity to kinases from other subfamilies. It also includes a large FERM domain. With the exception of certain types of blood cells, most cells express FAK. FAK tyrosine kinase activity can be activated, which plays a ke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ITGB1
Integrin beta-1 (ITGB1), also known as CD29, is a cell surface receptor that in humans is encoded by the ''ITGB1'' gene. This integrin associates with integrin alpha 1 and integrin alpha 2 to form integrin complexes which function as collagen receptors. It also forms dimers with integrin alpha 3 to form integrin receptors for netrin 1 and reelin. These and other integrin beta 1 complexes have been historically known as very late activation (VLA) antigens. Integrin beta 1 is expressed as at least four different isoforms. In cardiac muscle and skeletal muscle, the integrin beta-1D isoform is specifically expressed, and localizes to costameres, where it aids in the lateral force transmission from the Z-discs to the extracellular matrix. Abnormal levels of integrin beta-1D have been found in limb girdle muscular dystrophy and polyneuropathy. Structure Integrin beta-1 can exist as different isoforms via alternative splicing. Six alternatively spliced variants have been found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiomyocyte
Cardiac muscle (also called heart muscle, myocardium, cardiomyocytes and cardiac myocytes) is one of three types of vertebrate muscle tissues, with the other two being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall of the heart. The cardiac muscle (myocardium) forms a thick middle layer between the outer layer of the heart wall (the pericardium) and the inner layer (the endocardium), with blood supplied via the coronary circulation. It is composed of individual cardiac muscle cells joined by intercalated discs, and encased by collagen fibers and other substances that form the extracellular matrix. Cardiac muscle contracts in a similar manner to skeletal muscle, although with some important differences. Electrical stimulation in the form of a cardiac action potential triggers the release of calcium from the cell's internal calcium store, the sarcoplasmic reticulum. The rise in calcium causes the cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryogenesis
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm cell. The resulting fusion of these two cells produces a single-celled zygote that undergoes many cell divisions that produce cells known as blastomeres. The blastomeres are arranged as a solid ball that when reaching a certain size, called a morula, takes in fluid to create a cavity called a blastocoel. The structure is then termed a blastula, or a blastocyst in mammals. The mammalian blastocyst hatches before implantating into the endometrial lining of the womb. Once implanted the embryo will continue its development through the next stages of gastrulation, neurulation, and organogenesis. Gastrulation is the formation of the three germ layers that will form all of the different parts of the body. Neurulation forms the ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarcolemma
The sarcolemma (''sarco'' (from ''sarx'') from Greek; flesh, and ''lemma'' from Greek; sheath) also called the myolemma, is the cell membrane surrounding a skeletal muscle fiber or a cardiomyocyte. It consists of a lipid bilayer and a thin outer coat of polysaccharide material (glycocalyx) that contacts the basement membrane. The basement membrane contains numerous thin collagen fibrils and specialized proteins such as laminin that provide a scaffold to which the muscle fiber can adhere. Through transmembrane proteins in the plasma membrane, the actin skeleton inside the cell is connected to the basement membrane and the cell's exterior. At each end of the muscle fiber, the surface layer of the sarcolemma fuses with a tendon fiber, and the tendon fibers, in turn, collect into bundles to form the muscle tendons that adhere to bones. The sarcolemma generally maintains the same function in muscle cells as the plasma membrane does in other eukaryote cells. It acts as a barrier be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarcomere
A sarcomere (Greek σάρξ ''sarx'' "flesh", μέρος ''meros'' "part") is the smallest functional unit of striated muscle tissue. It is the repeating unit between two Z-lines. Skeletal muscles are composed of tubular muscle cells (called muscle fibers or myofibers) which are formed during embryonic myogenesis. Muscle fibers contain numerous tubular myofibrils. Myofibrils are composed of repeating sections of sarcomeres, which appear under the microscope as alternating dark and light bands. Sarcomeres are composed of long, fibrous proteins as filaments that slide past each other when a muscle contracts or relaxes. The costamere is a different component that connects the sarcomere to the sarcolemma. Two of the important proteins are myosin, which forms the thick filament, and actin, which forms the thin filament. Myosin has a long, fibrous tail and a globular head, which binds to actin. The myosin head also binds to ATP, which is the source of energy for muscle movement. Myo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intercalated Disc
Intercalated discs or lines of Eberth are microscopic identifying features of cardiac muscle. Cardiac muscle consists of individual heart muscle cells (cardiomyocytes) connected by intercalated discs to work as a single functional syncytium. By contrast, skeletal muscle consists of multinucleated muscle fibers and exhibits no intercalated discs. Intercalated discs support synchronized contraction of cardiac tissue. They occur at the Z line of the sarcomere and can be visualized easily when observing a longitudinal section of the tissue. Structure Intercalated discs are complex structures that connect adjacent cardiac muscle cells. The three types of cell junction recognised as making up an intercalated disc are desmosomes, fascia adherens junctions, and gap junctions. * Fascia adherens are anchoring sites for actin, and connect to the closest sarcomere. * Desmosomes prevent separation during contraction by binding intermediate filaments, anchoring the cell membrane to the inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterodimer
In biochemistry, a protein dimer is a macromolecular complex formed by two protein monomers, or single proteins, which are usually non-covalently bound. Many macromolecules, such as proteins or nucleic acids, form dimers. The word ''dimer'' has roots meaning "two parts", ''di-'' + '' -mer''. A protein dimer is a type of protein quaternary structure. A protein homodimer is formed by two identical proteins. A protein heterodimer is formed by two different proteins. Most protein dimers in biochemistry are not connected by covalent bonds. An example of a non-covalent heterodimer is the enzyme reverse transcriptase, which is composed of two different amino acid chains. An exception is dimers that are linked by disulfide bridges such as the homodimeric protein NEMO. Some proteins contain specialized domains to ensure dimerization (dimerization domains) and specificity. The G protein-coupled cannabinoid receptors have the ability to form both homo- and heterodimers with sever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protease
A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes (increases reaction rate or "speeds up") proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products. They do this by cleaving the peptide bonds within proteins by hydrolysis, a reaction where water breaks bonds. Proteases are involved in many biological functions, including digestion of ingested proteins, protein catabolism (breakdown of old proteins), and cell signaling. In the absence of functional accelerants, proteolysis would be very slow, taking hundreds of years. Proteases can be found in all forms of life and viruses. They have independently evolved multiple times, and different classes of protease can perform the same reaction by completely different catalytic mechanisms. Hierarchy of proteases Based on catalytic residue Proteases can be classified into seven broad groups: * Serine prot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
