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Survival Motor Neuron
Survival of motor neuron or survival motor neuron (SMN) is a protein that in humans is encoded by the ''SMN1'' and ''SMN2'' genes. SMN is found in the cytoplasm of all animal cells and also in the nuclear gems. It functions in transcriptional regulation, telomerase regeneration and cellular trafficking. SMN deficiency, primarily due to mutations in ''SMN1'', results in widespread splicing defects, especially in spinal motor neurons, and is one cause of spinal muscular atrophy. Research also showed a possible role of SMN in neuronal migration and/or differentiation. Function The SMN protein contains GEMIN2-binding, Tudor and YG-Box domains. It localizes to both the cytoplasm and the nucleus. Within the nucleus, the protein localizes to subnuclear bodies called gems which are found near coiled bodies containing high concentrations of small ribonucleoproteins (snRNPs). This protein forms heteromeric complexes with proteins such as GEMIN2 and GEMIN4, and also interacts with sev ... [...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 residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 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 peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Nucleus
The cell nucleus (pl. nuclei; from Latin or , meaning ''kernel'' or ''seed'') is a membrane-bound organelle found in eukaryotic cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a few others including osteoclasts have many. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm; and the nuclear matrix, a network within the nucleus that adds mechanical support. The cell nucleus contains nearly all of the cell's genome. Nuclear DNA is often organized into multiple chromosomes – long stands of DNA dotted with various proteins, such as histones, that protect and organize the DNA. The genes within these chromosomes are structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the cell by regulating gene expres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bcl-2
Bcl-2 (B-cell lymphoma 2), encoded in humans by the ''BCL2'' gene, is the founding member of the Bcl-2 family of regulator proteins that regulate cell death (apoptosis), by either inhibiting (anti-apoptotic) or inducing (pro-apoptotic) apoptosis. It was the first apoptosis regulator identified in any organism. Bcl-2 derives its name from ''B-cell lymphoma 2'', as it is the second member of a range of proteins initially described in chromosomal translocations involving chromosomes 14 and 18 in follicular lymphomas. Orthologs (such as ''Bcl2'' in mice) have been identified in numerous mammals for which complete genome data are available. Like BCL3, BCL5, BCL6, BCL7A, BCL9, and BCL10, it has clinical significance in lymphoma. Isoforms The two isoforms of Bcl-2, Isoform 1, and Isoform 2, exhibit a similar fold. However, results in the ability of these isoforms to bind to the BAD and BAK proteins, as well as in the structural topology and electrostatic potential of the binding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gem-associated Protein 7
Gem-associated protein 7 is a protein that in humans is encoded by the ''GEMIN7'' gene. The gem-associated proteins are those found in the gems of Cajal bodies. Function The protein encoded by this gene is a component of the core SMN complex, which is required for pre-mRNA splicing in the nucleus. The encoded protein is found in the nucleoplasm, in nuclear "gems" (Gemini of Cajal bodies), and in the cytoplasm. Three transcript variants encoding the same protein have been found for this gene. Interactions Gem-associated protein 7 has been shown to interact with SMN1 and Gem-associated protein 6 Gem-associated protein 6 is a protein that in humans is encoded by the ''GEMIN6'' gene. The gem-associated proteins are those found in the gems of Cajal bodies. Function GEMIN6 is part of a large macromolecular complex, the SMN localized to b .... References Further reading * * * External links PDBe-KB provides an overview of all the structure informa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gem-associated Protein 6
Gem-associated protein 6 is a protein that in humans is encoded by the ''GEMIN6'' gene. The gem-associated proteins are those found in the gems of Cajal bodies. Function GEMIN6 is part of a large macromolecular complex, the SMN localized to both the cytoplasm and the nucleus, that plays a role in the cytoplasmic assembly of small nuclear ribonucleoproteins (snRNPs). Other members of this complex include SMN (MIM 600354), GEMIN2 (SIP1; MIM 602595), GEMIN3 (DDX20; MIM 606168), GEMIN4 (MIM 606969), and GEMIN5 (MIM 607005). upplied by OMIMref name="entrez" /> Interactions Gem-associated protein 6 has been shown to interact with gem-associated protein 7 Gem-associated protein 7 is a protein that in humans is encoded by the ''GEMIN7'' gene. The gem-associated proteins are those found in the gems of Cajal bodies. Function The protein encoded by this gene is a component of the core SMN complex, .... References Further reading * * * {{gene-2-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gem-associated Protein 5
Gem-associated protein 5 is a protein that in humans is encoded by the ''GEMIN5'' gene. Function Gem-associated protein 5 is part of the SMN a large protein complex localized to both the cytoplasm and the nucleus that plays a role in the cytoplasmic assembly of small nuclear ribonucleoproteins (snRNPs). Other members of this complex include SMN (MIM 600354), gem-associated protein 2 (SIP1; MIM 602595), GEMIN3 (DDX20; MIM 606168), and GEMIN4 (MIM 606969). Interactions GEMIN5 has been shown to interact with DDX20 and SMN1 Survival of motor neuron 1 (''SMN1''), also known as component of gems 1 or ''GEMIN1'', is a gene that encodes the SMN protein in humans. Gene ''SMN1'' is the telomeric copy of the gene encoding the SMN protein; the centromeric copy is terme .... References Further reading * * * * * * * * * {{gene-5-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gem-associated Protein 4
Gem-associated protein 4 is a protein that in humans is encoded by the ''GEMIN4'' gene. Function The product of this gene is part of the SMN protein complex localized to the cytoplasm, nucleoli, and to discrete nuclear bodies called Gemini bodies (gems). The complex functions in spliceosomal snRNP assembly in the cytoplasm, and regenerates spliceosomes required for pre-mRNA splicing in the nucleus. The encoded protein directly interacts with a DEAD box protein and several spliceosome core proteins. Alternatively spliced transcript variants have been described, but their biological validity has not been determined. Interactions GEMIN4 has been shown to interact with: * DDX20, * EIF2C2, * LGALS1 and * SMN1 Survival of motor neuron 1 (''SMN1''), also known as component of gems 1 or ''GEMIN1'', is a gene that encodes the SMN protein in humans. Gene ''SMN1'' is the telomeric copy of the gene encoding the SMN protein; the centromeric copy is term .... References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DDX20
Probable ATP-dependent RNA helicase DDX20, also known as DEAD-box helicase 20 and gem-associated protein 3 (GEMIN3), is an enzyme that in humans is encoded by the ''DDX20'' gene. Function DEAD box proteins, characterized by the conserved motif Asp-Glu-Ala-Asp (DEAD), are putative RNA helicases. They are implicated in a number of cellular processes involving alteration of RNA secondary structure such as translation initiation, nuclear and mitochondrial splicing, and ribosome and spliceosome assembly. Based on their distribution patterns, some members of this family are believed to be involved in embryogenesis, spermatogenesis, and cellular growth and division. This gene encodes a DEAD box protein, which has an ATPase activity and is a component of the survival of motor neuron (SMN) complex. SMN is the spinal muscular atrophy gene product, and may play a catalytic role in the function of the SMN complex on RNPs. Clinical significance Previous research has revealed that DDX20 m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gem-associated Protein 2
Gem-associated protein 2 (GEMIN2), also called survival of motor neuron protein-interacting protein 1 (SIP1), is a protein that in humans is encoded by the ''GEMIN2'' gene. Interactions Gem-associated protein 2 has been shown to interact with DDX20 and SMN1. See also * Gideon Dreyfuss Gideon Dreyfuss is an American biochemist, the Isaac Norris Professor of Biochemistry and Biophysics at the University of Pennsylvania School of Medicine, and an investigator of the Howard Hughes Medical Institute. He was elected to the Nation ... * Spinal muscular atrophy References Further reading * * * * * * * * * * * * * * * * * {{gene-14-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spliceosome
A spliceosome is a large ribonucleoprotein (RNP) complex found primarily within the nucleus of eukaryotic cells. The spliceosome is assembled from small nuclear RNAs (snRNA) and numerous proteins. Small nuclear RNA (snRNA) molecules bind to specific proteins to form a small nuclear ribonucleoprotein complex (snRNP, pronounced “snurps”), which in turn combines with other snRNPs to form a large ribonucleoprotein complex called a spliceosome. The spliceosome removes introns from a transcribed pre-mRNA, a type of primary transcript. This process is generally referred to as splicing. An analogy is a film editor, who selectively cuts out irrelevant or incorrect material (equivalent to the introns) from the initial film and sends the cleaned-up version to the director for the final cut. However, sometimes the RNA within the intron acts as a ribozyme, splicing itself without the use of a spliceosome or protein enzymes. History In 1977, work by the Sharp and Roberts labs reveale ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SnRNP
snRNPs (pronounced "snurps"), or small nuclear ribonucleoproteins, are RNA-protein complexes that combine with unmodified pre-mRNA and various other proteins to form a spliceosome, a large RNA-protein molecular complex upon which splicing of pre-mRNA occurs. The action of snRNPs is essential to the removal of introns from pre-mRNA, a critical aspect of post-transcriptional modification of RNA, occurring only in the nucleus of eukaryotic cells. Additionally, '' U7 snRNP'' is not involved in splicing at all, as U7 snRNP is responsible for processing the 3′ stem-loop of histone pre-mRNA. The two essential components of snRNPs are protein molecules and RNA. The RNA found within each snRNP particle is known as ''small nuclear RNA'', or snRNA, and is usually about 150 nucleotides in length. The snRNA component of the snRNP gives specificity to individual introns by " recognizing" the sequences of critical splicing signals at the 5' and 3' ends and branch site of introns. The snRN ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
