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Sumoylation
In molecular biology, SUMO (Small Ubiquitin-like Modifier) proteins are a family of small proteins that are covalently attached to and detached from other proteins in cells to modify their function. This process is called SUMOylation (pronounced soo-muh-lā-shun and sometimes written sumoylation). SUMOylation is a post-translational modification involved in various cellular processes, such as nuclear-cytosolic transport, transcriptional regulation, apoptosis, protein stability, response to stress, and progression through the cell cycle. In human proteins, there are over 53,000 SUMO binding sites, making it a substantial component of fundamental biology. SUMO proteins are similar to ubiquitin and are considered members of the ubiquitin-like protein family. SUMOylation is directed by an enzymatic cascade analogous to that involved in ubiquitination. In contrast to ubiquitin, SUMO is not used to tag proteins for degradation. Mature SUMO is produced when the last four amino acids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post-translational Modification
In molecular biology, post-translational modification (PTM) is the covalent process of changing proteins following protein biosynthesis. PTMs may involve enzymes or occur spontaneously. Proteins are created by ribosomes, which translation (biology), translate mRNA into polypeptide chains, which may then change to form the mature protein product. PTMs are important components in cell signal transduction, signalling, as for example when prohormones are converted to hormones. Post-translational modifications can occur on the amino acid side chains or at the protein's C-terminus, C- or N-terminus, N- termini. They can expand the chemical set of the 22 proteinogenic amino acid, amino acids by changing an existing functional group or adding a new one such as phosphate. Phosphorylation is highly effective for controlling the enzyme activity and is the most common change after translation. Many eukaryotic and prokaryotic proteins also have carbohydrate molecules attached to them in a pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SUMO1
Small ubiquitin-related modifier 1 is a protein that in humans is encoded by the ''SUMO1'' gene. Function This gene encodes a protein that is a member of the SUMO (small ubiquitin-like modifier) protein family. It is a ubiquitin-like protein and functions in a manner similar to ubiquitin in that it is bound to target proteins as part of a post-translational modification system. However, unlike ubiquitin, which is primarily associated with targeting proteins for proteasomal degradation, SUMO1 is involved in a variety of cellular processes, such as nuclear transport, transcriptional regulation, apoptosis, and protein stability. It is not active until the last four amino acids of the carboxy-terminus have been cleaved off. Several pseudogenes have been reported for this gene. Alternate transcriptional splice variants encoding different isoforms have been characterized. Most cleft genes have a sumoylation component. Analysis of chromosomal anomalies in patients has led to the ide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ubiquitin-like Protein
Ubiquitin-like proteins (UBLs) are a family of small proteins involved in post-translational modification of other proteins in a cell (biology), cell, usually with a regulatory protein, regulatory function. The UBL protein family derives its name from the first member of the class to be discovered, ubiquitin (Ub), best known for its role in regulating protein degradation through covalent modification of other proteins. Following the discovery of ubiquitin, many additional evolutionarily related members of the group were described, involving parallel regulatory processes and similar chemistry. UBLs are involved in a widely varying array of cellular functions including autophagy, protein trafficking, inflammation and immune responses, transcription (biology), transcription, DNA repair, RNA splicing, and cellular differentiation. Discovery Ubiquitin itself was first discovered in the 1970s and originally named "ubiquitous immunopoietic polypeptide". Subsequently, other proteins with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Biology
Molecular biology is a branch of biology that seeks to understand the molecule, molecular basis of biological activity in and between Cell (biology), cells, including biomolecule, biomolecular synthesis, modification, mechanisms, and interactions. Though cells and other microscopic structures had been observed in living organisms as early as the 18th century, a detailed understanding of the mechanisms and interactions governing their behavior did not emerge until the 20th century, when technologies used in physics and chemistry had advanced sufficiently to permit their application in the biological sciences. The term 'molecular biology' was first used in 1945 by the English physicist William Astbury, who described it as an approach focused on discerning the underpinnings of biological phenomena—i.e. uncovering the physical and chemical structures and properties of biological molecules, as well as their interactions with other molecules and how these interactions explain observ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycine
Glycine (symbol Gly or G; ) is an amino acid that has a single hydrogen atom as its side chain. It is the simplest stable amino acid. Glycine is one of the proteinogenic amino acids. It is encoded by all the codons starting with GG (GGU, GGC, GGA, GGG). Glycine disrupts the formation of alpha-helices in secondary protein structure. Its small side chain causes it to favor random coils instead. Glycine is also an inhibitory neurotransmitter – interference with its release within the spinal cord (such as during a '' Clostridium tetani'' infection) can cause spastic paralysis due to uninhibited muscle contraction. It is the only achiral proteinogenic amino acid. It can fit into both hydrophilic and hydrophobic environments, due to its minimal side chain of only one hydrogen atom. History and etymology Glycine was discovered in 1820 by French chemist Henri Braconnot when he hydrolyzed gelatin by boiling it with sulfuric acid. He originally called it "sugar of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoform
A protein isoform, or "protein variant", is a member of a set of highly similar proteins that originate from a single gene and are the result of genetic differences. While many perform the same or similar biological roles, some isoforms have unique functions. A set of protein isoforms may be formed from alternative splicings, variable promoter usage, or other post-transcriptional modifications of a single gene; post-translational modifications are generally not considered. (For that, see Proteoforms.) Through RNA splicing mechanisms, mRNA has the ability to select different protein-coding segments ( exons) of a gene, or even different parts of exons from RNA to form different mRNA sequences. Each unique sequence produces a specific form of a protein. The discovery of isoforms could explain the discrepancy between the small number of protein coding regions of genes revealed by the human genome project and the large diversity of proteins seen in an organism: different proteins e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GeneRIF
A GeneRIF or Gene Reference Into Function is a short (255 characters or fewer) statement about the function of a gene. GeneRIFs provide a simple mechanism for allowing scientists to add to the functional annotation of genes described in the Entrez Gene database. In practice, ''function'' is constructed quite broadly. For example, there are GeneRIFs that discuss the role of a gene in a disease, GeneRIFs that point the viewer towards a review article about the gene, and GeneRIFs that discuss the structure of a gene. However, the stated intent is for GeneRIFs to be about gene function. Currently over half a million geneRIFs have been created for genes from almost 1000 different species. GeneRIFs are always associated with specific entries in the Entrez Gene database. Each GeneRIF has a pointer to the PubMed ID (a type of document identifier) of a scientific publication that provides evidence for the statement made by the GeneRIF. GeneRIFs are often extracted directly from the docum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centrosome
In cell biology, the centrosome (Latin centrum 'center' + Greek sōma 'body') (archaically cytocentre) is an organelle that serves as the main microtubule organizing center (MTOC) of the animal cell, as well as a regulator of cell-cycle progression. The centrosome provides structure for the cell. It is thought to have evolved only in the metazoan lineage of eukaryotic cells. Fungi and plants lack centrosomes and therefore use other structures to organize their microtubules. Although the centrosome has a key role in efficient mitosis in animal cells, it is not essential in certain fly and flatworm species. Centrosomes are composed of two centrioles arranged at right angles to each other, and surrounded by a dense, highly structured mass of protein termed the pericentriolar material (PCM). The PCM contains proteins responsible for microtubule nucleation and anchoring — including γ-tubulin, pericentrin and ninein. In general, each centriole of the centrosome is based on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ninein
Ninein is a protein that in humans is encoded by the ''NIN'' gene. Function Ninein, together with its paralog Ninein-like protein is one of the proteins important for centrosomal function. Localization of this protein to the centrosome requires three leucine zippers in the central coiled-coil domain. Multiple alternatively spliced transcript variants that encode different isoforms have been reported. This protein is important for positioning and anchoring the microtubules minus-ends in epithelial cell Epithelium or epithelial tissue is a thin, continuous, protective layer of Cell (biology), cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial (Mesothelium, mesothelial) tissues line ...s. References Further reading * * * * * * * * * * * * * * * * * EF-hand-containing proteins {{gene-14-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RANGAP1
Ran GTPase-activating protein 1 is an enzyme that in humans is encoded by the ''RANGAP1'' gene. Function RanGAP1, is a homodimeric 65-kD polypeptide that specifically induces the GTPase activity of RAN, but not of RAS by over 1,000-fold. RanGAP1 is the immediate antagonist of RCC1, a regulator molecule that keeps RAN in the active, GTP-bound state. The RANGAP1 gene encodes a 587-amino acid polypeptide. The sequence is unrelated to that of GTPase activators for other RAS-related proteins, but is 88% identical to Rangap1 (Fug1), the murine homolog of yeast Rna1p. RanGAP1 and RCC1 control RAN-dependent transport between the nucleus and cytoplasm. RanGAP1 is a key regulator of the RAN GTP/GDP cycle. Interactions RanGAP1 is a trafficking protein which helps transport other proteins from the cytoplasm to the nucleus. Small ubiquitin-related modifier needs to be associated with it before it can be localized at the nuclear pore. RANGAP1 has been shown to interact with: * R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
