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Inner Nuclear Membrane Protein
Inner nuclear membrane proteins (INM proteins) are membrane proteins that are embedded in or associated with the Inner nuclear membrane, inner membrane of the nuclear envelope. There are about 60 INM proteins, most of which are poorly characterized with respect to structure and function. Among the few well-characterized INM proteins are lamin B receptor (LBR), TOR1AIP1, lamina-associated polypeptide 1 (LAP1), thymopoietin, lamina-associated polypeptide-2 (LAP2), emerin and LEM domain-containing protein 3, MAN1. Common structural features Several integral nuclear membrane proteins of different size and structure have been identified. It is proposed that they share some structural features with respect to nucleoplasmic Protein domain, domain(s) and lipid-soluble domain(s). Some INM proteins contain common protein domain structures, and can thus be categorised into known Protein family#Protein domains and motifs, protein domain families. These include the LEM domain, LEM-, SUN domai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteins Of The Inner Nuclear Membrane
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metabolic reactions, DNA replication, Cell signaling, responding to stimuli, providing Cytoskeleton, structure to cells and Fibrous protein, organisms, and Intracellular transport, transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the Nucleic acid sequence, nucleotide sequence of their genes, and which usually results in protein folding into a specific Protein structure, 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 pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoskeleton
The cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including those of bacteria and archaea. In eukaryotes, it extends from the cell nucleus to the cell membrane and is composed of similar proteins in the various organisms. It is composed of three main components: microfilaments, intermediate filaments, and microtubules, and these are all capable of rapid growth and or disassembly depending on the cell's requirements. Cytoskeleton can perform many functions. Its primary function is to give the cell its shape and mechanical resistance to deformation, and through association with extracellular connective tissue and other cells it stabilizes entire tissues. The cytoskeleton can also contract, thereby deforming the cell and the cell's environment and allowing cells to migrate. Moreover, it is involved in many cell signaling pathways and in the uptake of extracellular material ( endocytosis), the segregation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outer Nuclear Membrane
The nuclear envelope, also known as the nuclear membrane, is made up of two lipid bilayer membranes that in eukaryotic cells surround the nucleus, which encloses the genetic material. The nuclear envelope consists of two lipid bilayer membranes: an inner nuclear membrane and an outer nuclear membrane. The space between the membranes is called the perinuclear space. It is usually about 10–50 nm wide. The outer nuclear membrane is continuous with the endoplasmic reticulum membrane. The nuclear envelope has many nuclear pores that allow materials to move between the cytosol and the nucleus. Intermediate filament proteins called lamins form a structure called the nuclear lamina on the inner aspect of the inner nuclear membrane and give structural support to the nucleus. Structure The nuclear envelope is made up of two lipid bilayer membranes, an inner nuclear membrane and an outer nuclear membrane. These membranes are connected to each other by nuclear pores. Two sets of inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scaffold Protein
In biology, scaffold proteins are crucial regulators of many key signalling pathways. Although scaffolds are not strictly defined in function, they are known to interact and/or bind with multiple members of a signalling pathway, tethering them into complexes. In such pathways, they regulate signal transduction and help localize pathway components (organized in complexes) to specific areas of the cell such as the plasma membrane, the cytoplasm, the nucleus, the Golgi, endosomes, and the mitochondria. History The first signaling scaffold protein discovered was the Ste5 protein from the yeast ''Saccharomyces cerevisiae''. Three distinct domains of Ste5 were shown to associate with the protein kinases Ste11, Ste7, and Fus3 to form a multikinase complex. Function Scaffold proteins act in at least four ways: tethering signaling components, localizing these components to specific areas of the cell, regulating signal transduction by coordinating positive and negative feedback s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Lamina
The nuclear lamina is a dense (~30 to 100 nm thick) fibrillar network inside the nucleus of eukaryote cells. It is composed of intermediate filaments and membrane associated proteins. Besides providing mechanical support, the nuclear lamina regulates important cellular events such as DNA replication and cell division. Additionally, it participates in chromatin organization and it anchors the nuclear pore complexes embedded in the nuclear envelope. The nuclear lamina is associated with the inner face of the inner nuclear membrane of the nuclear envelope, whereas the outer face of the outer nuclear membrane is continuous with the endoplasmic reticulum. The nuclear lamina is similar in structure to the nuclear matrix, that extends throughout the nucleoplasm. Structure and composition The nuclear lamina consists of two components, lamins and nuclear lamin-associated membrane proteins. The lamins are type V intermediate filaments which can be categorized as either A-type ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Membrane
The nuclear envelope, also known as the nuclear membrane, is made up of two lipid bilayer polar membrane, membranes that in eukaryotic cells surround the Cell nucleus, nucleus, which encloses the genome, genetic material. The nuclear envelope consists of two lipid bilayer membranes: an inner nuclear membrane and an outer nuclear membrane. The space between the membranes is called the perinuclear space. It is usually about 10–50 Nanometre, nm wide. The outer nuclear membrane is continuous with the endoplasmic reticulum membrane. The nuclear envelope has many nuclear pores that allow materials to move between the cytosol and the nucleus. Intermediate filament proteins called lamins form a structure called the nuclear lamina on the inner aspect of the inner nuclear membrane and give structural support to the nucleus. Structure The nuclear envelope is made up of two lipid bilayer membranes, an inner nuclear membrane and an outer nuclear membrane. These membranes are connected t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histone Deacetylase
Histone deacetylases (, HDAC) are a class of enzymes that remove acetyl groups (O=C-CH3) from an ε-N-acetyl lysine amino acid on both histone and non-histone proteins. HDACs allow histones to wrap the DNA more tightly. This is important because DNA is wrapped around histones, and DNA expression is regulated by acetylation and de-acetylation. HDAC's action is opposite to that of histone acetyltransferase. HDAC proteins are now also called lysine deacetylases (KDAC), to describe their function rather than their target, which also includes non-histone proteins. In general, they suppress gene expression. HDAC super family Together with the acetylpolyamine amidohydrolases and the acetoin utilization proteins, the histone deacetylases form an ancient protein superfamily known as the histone deacetylase superfamily. Classes of HDACs in higher eukaryotes HDACs, are classified in four classes depending on sequence homology to the yeast original enzymes and domain organization: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Expression
Gene expression is the process (including its Regulation of gene expression, regulation) by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, proteins or non-coding RNA, and ultimately affect a phenotype. These products are often proteins, but in non-protein-coding genes such as Transfer RNA, transfer RNA (tRNA) and Small nuclear RNA, small nuclear RNA (snRNA), the product is a functional List of RNAs, non-coding RNA. The process of gene expression is used by all known life—eukaryotes (including multicellular organisms), prokaryotes (bacteria and archaea), and viruses—to generate the macromolecule, macromolecular machinery for life. In genetics, gene expression is the most fundamental level at which the genotype gives rise to the phenotype, ''i.e.'' observable trait. The genetic information stored in DNA represents the genotype, whereas the phenotype results from the "interpretation" of that informati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and non-coding genes. During gene expression (the synthesis of Gene product, RNA or protein from a gene), DNA is first transcription (biology), copied into RNA. RNA can be non-coding RNA, directly functional or be the intermediate protein biosynthesis, template for the synthesis of a protein. The transmission of genes to an organism's offspring, is the basis of the inheritance of phenotypic traits from one generation to the next. These genes make up different DNA sequences, together called a genotype, that is specific to every given individual, within the gene pool of the population (biology), population of a given species. The genotype, along with environmental and developmental factors, ultimately determines the phenotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Repressor
In molecular genetics, a repressor is a DNA- or RNA-binding protein that inhibits the expression of one or more genes by binding to the operator or associated silencers. A DNA-binding repressor blocks the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes into messenger RNA. An RNA-binding repressor binds to the mRNA and prevents translation of the mRNA into protein. This blocking or reducing of expression is called repression. Function If an inducer, a molecule that initiates the gene expression, is present, then it can interact with the repressor protein and detach it from the operator. RNA polymerase then can transcribe the message (expressing the gene). A co-repressor is a molecule that can bind to the repressor and make it bind to the operator tightly, which decreases transcription. A repressor that binds with a co-repressor is termed an ''aporepressor'' or ''inactive repressor''. One type of aporepressor is the trp repre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barrier-to-autointegration Factor
In molecular biology, barrier-to-autointegration factor (BAF) is a family of essential proteins that is Conservation (genetics), highly conserved in metazoan evolution, and which may act as DNA-bridging proteins. BAF Binding (molecular), binds directly to double-stranded DNA, to transcription (genetics), transcription activators, and to inner nuclear membrane proteins, including lamin A filaments that anchor nuclear pore complexes in place, and nuclear LEM-domain proteins that bind to lamin filaments and chromatin. New findings suggest that BAF has structural roles in nuclear assembly and chromatin organization, represses gene expression and might interlink chromatin structure, nuclear architecture and gene regulation in metazoans. BAF can be exploited by retroviruses to act as a host component of pre-integration complexes, which promote the integration of the retroviral DNA into the host chromosome by preventing autointegration (integration into itself). BAF might contribute to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Pore
The nuclear pore complex (NPC), is a large protein complex giving rise to the nuclear pore. A great number of nuclear pores are studded throughout the nuclear envelope that surrounds the eukaryote cell nucleus. The pores enable the nuclear transport of macromolecules between the nucleoplasm of the nucleus and the cytoplasm of the Cell (biology), cell. Small molecules can easily Passive diffusion, diffuse through the pores. Nuclear transport includes the transportation of RNA and ribosomal proteins from the nucleus to the cytoplasm, and the transport of proteins (such as DNA polymerase and lamins), carbohydrates, signaling molecules, and lipids into the nucleus. Each nuclear pore complex can actively mediate up to 1000 translocations per second. The nuclear pore complex consists predominantly of a Protein family, family of proteins known as nucleoporins (Nups). Each pore complex in the human cell nucleus is composed of about 1,000 individual protein molecules, from an Conserved s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
