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Lamin B Receptor
Lamin-B receptor is a protein, and in humans, it is encoded by the ''LBR'' gene. Function The protein encoded by this gene belongs to the ERG4/ ERG24 family. It localizes to the inner membrane of the nuclear envelope and anchors the lamina and the heterochromatin to the membrane. It may mediate the interaction between chromatin and lamin B. Mutations of this gene has been associated with autosomal recessive HEM/Greenberg skeletal dysplasia. Alternative splicing occurs at this locus and two transcript variants encoding the same protein have been identified. Clinical significance There is evidence tying it to Greenberg dysplasia and Pelger-Huet anomaly. Interactions Lamin B receptor has been shown to interact with CBX3 and CBX5. LBR also interacts with long non-coding RNA XIST in mouse cells and potentially assist the spreading XIST across X chromosome The X chromosome is one of the two sex chromosomes in many organisms, including mammals, and is found in both mal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid 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] |
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] |
ERG4
ERG4 or Delta(24(24(1)))-sterol reductase or Delta(24(28))-sterol reductase is an enzyme that catalyzes the last step of ergosterol biosynthesis pathway in fungi ''Saccharomyces cerevisiae ''Saccharomyces cerevisiae'' () (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungal microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have be ...'' (Baker's yeast), which 5,7,22,24(28)- ergostatetraenol converted into ergosterol. References EC 1.3.1 Saccharomyces cerevisiae genes {{Enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ERG24
In enzymology, a Delta14-sterol reductase () is an enzyme that catalyzes the chemical reaction :4,4-dimethyl-5alpha-cholesta-8,24-dien-3beta-ol + NADP+ \rightleftharpoons 4,4-dimethyl-5alpha-cholesta-8,14,24-trien-3beta-ol + NADPH + H+ Thus, the two substrates of this enzyme are 4,4-dimethyl-5alpha-cholesta-8,24-dien-3beta-ol and NADP+, whereas its 3 products are 4,4-dimethyl-5alpha-cholesta-8,14,24-trien-3beta-ol, NADPH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 4,4-dimethyl-5alpha-cholesta-8,24-dien-3beta-ol:NADP+ Delta14-oxidoreductase. This enzyme participates in biosynthesis of steroids A steroid is an organic compound with four fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inner Nuclear Membrane Proteins
Inner nuclear membrane proteins (INM proteins) are membrane proteins that are embedded in or associated with the 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), lamina-associated polypeptide 1 (LAP1), lamina-associated polypeptide-2 (LAP2), emerin and 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 domain(s) and lipid-soluble domain(s). Some INM proteins contain common protein domain structures, and can thus be categorised into known protein domain families. These include the LEM-, SUN-, and KASH-domain families. Members of the LEM-domain family play a part in chromatin organisation . SUN- and KASH-domains participate in linking ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Envelope
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterochromatin
Heterochromatin is a tightly packed form of DNA or '' condensed DNA'', which comes in multiple varieties. These varieties lie on a continuum between the two extremes of constitutive heterochromatin and facultative heterochromatin. Both play a role in the expression of genes. Because it is tightly packed, it was thought to be inaccessible to polymerases and therefore not transcribed; however, according to Volpe et al. (2002), and many other papers since, much of this DNA is in fact transcribed, but it is continuously turned over via RNA-induced transcriptional silencing (RITS). Recent studies with electron microscopy and OsO4 staining reveal that the dense packing is not due to the chromatin. Constitutive heterochromatin can affect the genes near itself (e.g. position-effect variegation). It is usually repetitive and forms structural functions such as centromeres or telomeres, in addition to acting as an attractor for other gene-expression or repression signals. Facultativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamin B
Lamin B2 is a protein that in humans is encoded by the ''LMNB2'' gene. It is the second of two type B nuclear lamins, and it is associated with laminopathies. See also * Lamin B receptor Lamin-B receptor is a protein, and in humans, it is encoded by the ''LBR'' gene. Function The protein encoded by this gene belongs to the ERG4/ ERG24 family. It localizes to the inner membrane of the nuclear envelope and anchors the lamina a ... * Barraquer–Simons syndrome * Pelger–Huët anomaly External links * References Genes mutated in mice {{biochemistry-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenberg Dysplasia
Hydrops-ectopic calcification-moth-eaten skeletal dysplasia is a defect in cholesterol biosynthesis. Greenberg characterized the condition in 1988. It has been associated with the lamin B receptor. Signs and Symptoms Hydrops-ectopic calcification-moth-eaten skeletal dysplasia causes the bones in a fetus to develop abnormally. This leads to a characteristic "moth eaten" appearance of the bones when viewed under an X-ray. Micromelia, polydactyly and ectopic calcification, or the built up of calcium in the soft tissues of the body, may all occur. Eighty to ninety nine percent of effected individuals will have abnormally ossified vertebrae, abnormal pelvis bone ossification, anterior rib punctate calcifications and brachydactyly. The second defining feature of hydrops-ectopic calcification-moth-eaten skeletal dysplasia is hydrops fetalis. See also * Ectopic calcification * Hydrops Hydrops may refer to: Medicine * Hydrops ( ), the excessive accumulation of serous fluid in tissues ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CBX3
Chromobox protein homolog 3 is a protein that is encoded by the ''CBX3'' gene in humans. At the nuclear envelope, the nuclear lamina and heterochromatin are adjacent to the inner nuclear membrane. The protein encoded by this gene binds DNA and is a component of heterochromatin. This protein also can bind lamin B receptor, an integral membrane protein found in the inner nuclear membrane. The dual binding functions of the encoded protein may explain the association of heterochromatin with the inner nuclear membrane. Two transcript variants encoding the same protein but differing in the 5' UTR, have been found for this gene. Interactions CBX3 has been shown to interact with PIM1, Ki-67, Lamin B receptor Lamin-B receptor is a protein, and in humans, it is encoded by the ''LBR'' gene. Function The protein encoded by this gene belongs to the ERG4/ ERG24 family. It localizes to the inner membrane of the nuclear envelope and anchors the lamina a ..., CBX5 and CBX1. See also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
