Ribonucleoprotein

A ribonucleoprotein complex that contains the 7SK snRNA. The 7SK snRNP plays a central role in RNA polymerase II elongation control by regulating the availability of active P-TEFb.

A large ribonucleoprotein complex considered to be the earliest preribosomal complex. In S. cerevisiae, it has a size of 90S and consists of the 35S pre-rRNA, early-associating ribosomal proteins most of which are part of the small ribosomal subunit, the U3 snoRNA and associated proteins.

The degradosome is a protein complex playing a key role in mRNA degradation and RNA processing. It includes a RNA helicase, a 3'-5' phosphate-dependent PNPase and a RNase E bound-enolase.

A class of nuclear body, first seen after silver staining by Ramon y Cajal in 1903, enriched in small nuclear ribonucleoproteins, and certain general RNA polymerase II transcription factors; ultrastructurally, they appear as a tangle of coiled, electron-dense threads roughly 0.5 micrometers in diameter; involved in aspects of snRNP biogenesis; the protein coilin serves as a marker for Cajal bodies. Some argue that Cajal bodies are the sites for preassembly of transcriptosomes, unitary particles involved in transcription and processing of RNA.

A spliceosomal complex that is formed by the displacement of the two snRNPs from the precatalytic spliceosome; three snRNPs including U5 remain associated with the mRNA. This complex, sometimes called the activated spliceosome, is the catalytically active form of the spliceosome, and includes many proteins in addition to those found in the associated snRNPs.

A spliceosomal complex that contains three snRNPs, including U5, bound to a splicing intermediate in which the first catalytic cleavage of the 5' splice site has occurred. The precise subunit composition differs significantly from that of the catalytic step 1, or activated, spliceosome, and includes many proteins in addition to those found in the associated snRNPs.

A spliceosomal complex that is formed by association of the U1 snRNP with the 5' splice site of an unspliced intron in an RNA transcript.

A ribonuclease P complex located in the cyanelle, where it catalyzes the 5' endonucleolytic cleavage of precursor tRNAs to yield mature tRNAs. The best characterized cyanelle ribonuclease P complex, from the alga Cyanophora paradoxa, contains a single RNA molecule that is necessary but not sufficient for catalysis, and several protein molecules.

A ribonuclease complex that has 3-prime to 5-prime processive hydrolytic exoribonuclease activity producing 5-prime-phosphomonoesters. Participates in a multitude of cellular RNA processing and degradation events preventing nuclear export and/or translation of aberrant RNAs. Restricted to processing linear and circular single-stranded RNAs (ssRNA) only. RNAs with complex secondary structures may have to be unwound or pre-processed by co-factors prior to entering the complex, esp if the 3-prime end is structured.

A dense aggregation in the cytosol composed of proteins and RNAs that appear when the cell is under stress.

A ribonuclease P complex that contains a single RNA molecule that is necessary and usually sufficient for catalysis, and a single protein molecule.

A ribonuclease complex with 3'-to-5' exoribonuclease activity that participates in RNA processing and degradation.

A membraneless cytoplasmic ribonucleoprotein assembly that concentrates glycolytic enzymes and associated RNAs during hypoxic growth of Saccharomyces cerevisiae.

A stress-responsive, polar, membraneless ribonucleoprotein condensate organized by Hfq in Escherichia coli, with polyphosphate-modulated assembly and enrichment of polyadenylated transcripts and RNA-processing proteins.

A nuclear body associated with the histone gene locus that is thought to contain all of the factors necessary for histone mRNA transcription and pre-mRNA processing. In Drosophila, U7 snRNP is located in the histone locus body rather than the distinct Cajal body.

A class of nuclear body measuring 20-25 nm in diameter and distributed throughout the interchromatin space, linked together by thin fibrils. They are believed to be storage centers for various snRNAs, snRNPs, serine/arginine-rich proteins and RNA polymerase II. A typical mammalian cell contains 25-50 clusters of interchromatin granules. Interchromatin granule clusters do not contain the heterogeneous nuclear RNA-binding proteins (hnRNPs).

The larger of the two subunits of a ribosome. Two sites on the ribosomal large subunit are involved in translation, namely the aminoacyl site (A site) and peptidyl site (P site).

Heteroheptameric Sm-like protein ring complex composed of Lsm2, Lsm3, Lsm4, Lsm5, Lsm6, Lsm7 and Lsm8 or their orthologs that associates with U6-family spliceosomal snRNAs.

A ribonuclease P complex that generally contains a single RNA molecule and several protein molecules. Examples of this complex are found in Archaeal species.

A small round nuclear body, measuring 0.2-0.8 microns in diameter that is diffusely distributed throughout the nucleoplasm. Several proteins known to be involved in miRNA processing have been localized to these structures. D-bodies are thought to be involved in primary-miRNA processing and/or storage/assembly of miRNA processing complexes.

A ribonuclease complex that has 3-prime to 5-prime processive and distributive hydrolytic exoribonuclease activity and endoribonuclease activity, producing 5-prime-phosphomonoesters. Participates in a multitude of cellular RNA processing and degradation events preventing nuclear export and/or translation of aberrant RNAs. Restricted to processing linear and circular single-stranded RNAs (ssRNA) only. RNAs with complex secondary structures may have to be unwound or pre-processed by co-factors prior to entering the complex, esp if the 3-prime end is structured.

A discrete extra-nucleolar subnuclear domain, 20-50 in number, in which splicing factors are seen to be localized by immunofluorescence microscopy.

A dense aggregation in the nucleus composed of proteins and RNAs that appear when the cell is under stress.

A ribonuclease complex that has 3-prime to 5-prime distributive hydrolytic exoribonuclease activity and in some taxa (e.g. yeast) endoribonuclease activity, producing 5-prime-phosphomonoesters. Participates in a multitude of cellular RNA processing and degradation events preventing nuclear export and/or translation of aberrant RNAs. Restricted to processing linear and circular single-stranded RNAs (ssRNA) only. RNAs with complex secondary structures may have to be unwound or pre-processed by co-factors prior to entering the complex, esp if the 3-prime end is structured.

A ribonuclease P complex located in the nucleolus of a eukaryotic cell, where it catalyzes the 5' endonucleolytic cleavage of precursor tRNAs to yield mature tRNAs. Eukaryotic nucleolar ribonuclease P complexes generally contain a single RNA molecule that is necessary but not sufficient for catalysis, and several protein molecules.

A nucleoplasmic speckle distributed in the interchromatin space of cells in close proximity to chromatin. Omega speckles are distinct from interchromatin granules and contain heterogeneous nuclear RNA-binding proteins (hnRNPs).

A focus in the cytoplasm where mRNAs may become inactivated by decapping or some other mechanism. Protein and RNA localized to these foci are involved in mRNA degradation, nonsense-mediated mRNA decay (NMD), translational repression, and RNA-mediated gene silencing.

Discrete subnuclear bodies in the interchromatin nucleoplasmic space, often located adjacent to nuclear specks. 10-20 paraspeckles are typically found in human cell nuclei.

A ribonucleoprotein complex that is formed by the association of the U1, U2, U4/U6 and U5 small nuclear ribonucleoproteins.

The perinucleolar compartment (PNC) is a subnuclear structure associated with, but structurally distinct from, the nucleolus. The PNC contains large amounts of the heterogeneous nuclear ribonucleoprotein complex (hnRNP) called hnRNP I (PTB). Many RNA binding proteins as well as RNA polymerase III transcripts are highly enriched in this compartment. PTB and pol III transcripts are required for the integrity of the PNC.

A spliceosomal complex that is formed following the release of the spliced product from the post-spliceosomal complex and contains the excised intron and three snRNPs, either U2 or U12, U5, and either U6 or U6atac.

A spliceosomal complex that is formed following the second splicing event and contains the spliced product, the excised intron, and three snRNPs, including U5.

A spliceosomal complex that is formed by the recruitment of a preassembled U5-containing tri-snRNP to the prespliceosome. Although all 5 snRNPs are present, the precatalytic spliceosome is catalytically inactive. The precatalytic spliceosome includes many proteins in addition to those found in the associated snRNPs.

Any complex of pre-rRNAs, ribosomal proteins, and associated proteins formed during ribosome biogenesis.

A preribosomal complex consisting of 27SA, 27SB, and/or 7S pre-rRNA, 5S rRNA, ribosomal proteins including late-associating large subunit proteins, and associated proteins; a precursor of the eukaryotic cytoplasmic large ribosomal subunit.

A preribosomal complex consisting of 20S pre-rRNA, ribosomal proteins including late-associating small subunit proteins, and associated proteins; a precursor of the eukaryotic cytoplasmic small ribosomal subunit.

A spliceosomal complex that is formed by association of the 5' splice site and the branch point sequence with specific snRNPs. The prespliceosome includes many proteins in addition to those found in the bound snRNPs. Commitment to a given pair of 5' and 3' splice sites occurs at the time of prespliceosome formation. Prespliceosome complexes are not active for splicing, but are instead an early step in the assembly of a spliceosomal complex.

A ribonucleoprotein complex that contains an RNA molecule of the snoRNA family, and cleaves the rRNA precursor as part of rRNA transcript processing. It also has other roles: In S. cerevisiae it is involved in cell cycle-regulated degradation of daughter cell-specific mRNAs, while in mammalian cells it also enters the mitochondria and processes RNAs to create RNA primers for DNA replication.

A ribonucleoprotein complex that catalyzes cleavage of the leader sequence of precursor tRNAs (pre-tRNAs), generating the mature 5' end of tRNAs.

The ribonucleoprotein particle that translates mRNA into protein. The bacterial and archaeal 70S ribosome comprises a small (30S) subunit built on 16S rRNA, which decodes the mRNA, and a large (50S) subunit built on 23S and 5S rRNA, whose 23S rRNA catalyses peptide bond formation. This record details that 70S form and the functional core shared with the larger eukaryotic cytosolic 80S ribosome; it does not enumerate 80S-specific components.

A ribonucleoprotein granule located in the cytoplasm of bacteria, minimally containing the RNase E protein and RNA molecules. Bacterial RNP-bodies are similar to eukaryotic P-bodies and stress granules.

A complex of protein and RNA which facilitates translocation of proteins across membranes.

A ribonucleoprotein complex that contains spliced leader (SL) RNA and associated proteins.

A ribonucleoprotein complex that contains at least one small nuclear RNA (snRNA) and associated proteins. Small nuclear ribonucleoproteins are typically named for the snRNA constituents they contain, such as U1 snRNP, U4/U6 snRNP, or 7SK snRNP; many become part of spliceosomes, while others regulate transcription elongation or replication-dependent histone pre-mRNA 3'-end processing.

The smaller of the two subunits of a ribosome.

A large ribonucleoprotein complex that is an early preribosomal complex. In S. cerevisiae, it has a size of 80S and consists of the 35S pre-rRNA, early-associating ribosomal proteins most of which are part of the small ribosomal subunit, the U3 snoRNA and associated proteins.

A ribonucleoprotein complex that contains an RNA molecule of the snoRNA family and associated proteins. Many are involved in a step of processing of rRNA molecules: cleavage, 2'-O-methylation, or pseudouridylation, but other RNA types can be targets as well. The majority fall into one of two classes, box C/D type or box H/ACA type, which are conserved across eukaryotes and archaea. Other members include the telomerase RNA and the ribonuclease MRP RNA.

A nuclear body that is found in the germinal vesicles of amphibian oocytes, and consist of three major parts: a remarkably spherical body about 5-10 pm in diameter, smaller spherical or nearly spherical granules on the surface, and inclusions of various sizes that strongly resemble the surface granules. The parts of the sphere organelle have distinct compositions, including splicing snRNAs and proteins.

Any of a series of ribonucleoprotein complexes that contain snRNA(s) and small nuclear ribonucleoproteins (snRNPs), and are formed sequentially during the spliceosomal splicing of one or more substrate RNAs, and which also contain the RNA substrate(s) from the initial target RNAs of splicing, the splicing intermediate RNA(s), to the final RNA products. During cis-splicing, the initial target RNA is a single, contiguous RNA transcript, whether mRNA, snoRNA, etc., and the released products are a spliced RNA and an excised intron, generally as a lariat structure. During trans-splicing, there are two initial substrate RNAs, the spliced leader RNA and a pre-mRNA.

A small ribonucleoprotein complex involved in formation of the spliceosome.

A spliceosomal snRNP complex that is formed by the association of the U4/U6 (or U4atac/U6atac) snRNP with the U5 snRNP.

Multicomponent complex of RNA and proteins that is composed of four active spliceosomes, termed native spliceosomes, connected to each other by the pre-mRNA. The supraspliceosome is the nuclear machine where the pre-mRNA processing takes place, like the 5'-end capping, 3'-end cleavage, splicing and editing.

Telomerase is a ribonucleoprotein enzyme complex, with a minimal catalytic core composed of a catalytic reverse transcriptase subunit and an RNA subunit that provides the template for telomeric DNA addition. In vivo, the holoenzyme complex often contains additional subunits.

A polar, membraneless ribonucleoprotein condensate organized by TmaR in Escherichia coli that recruits phosphotransferase-system enzyme I and participates in spatial regulation of sugar utilization.

A spliceosomal complex that forms during the addition of a specific spliced leader (SL) sequence to the 5'-end of a messenger RNA primary transcript, a process which occurs in a number of eukaryotic organisms, including trypanosomatid protozoans, euglenoids, nematodes, trematodes, and chordates.

A ribonucleoprotein complex that contains small nuclear RNA U11, a heptameric ring of Sm proteins, as well as several proteins that are unique to the U11 snRNP, most of which remain associated with the U11 snRNA both while the U11 snRNP is free or assembled into a series of spliceosomal complexes.

A ribonucleoprotein complex that is formed by the association of the U11 and U12 small nuclear ribonucleoproteins.

A ribonucleoprotein complex that contains small nuclear RNA U12, a heptameric ring of Sm proteins, as well as several proteins that are unique to the U12 snRNP, most of which remain associated with the U12 snRNA both while the U12 snRNP is free or assembled into a series of spliceosomal complexes.

A spliceosomal complex that is formed by the displacement of the U11 and U4atac snRNPs from the precatalytic spliceosome; the U12, U5 and U6atac snRNPs remain associated with the mRNA. This complex, sometimes called the activated spliceosome, is the catalytically active form of the spliceosome, and includes many proteins in addition to those found in the U12, and U5 and U6atac snRNPs.

A spliceosomal complex that contains the U12, U5 and U6atac snRNPs bound to a splicing intermediate in which the first catalytic cleavage of the 5' splice site has occurred. The precise subunit composition differs significantly from that of the catalytic step 1, or activated, spliceosome, and includes many proteins in addition to those found in the U12, U5 and U6atac snRNPs.

A spliceosomal complex that is formed following the release of the spliced product from the post-spliceosomal complex and contains the excised intron and the U12, U5 and U6atac snRNPs.

A spliceosomal complex that is formed following the second splicing event and contains the spliced product, the excised intron, and three snRNPs, U5, U12 and U6atac.

A spliceosomal complex that is formed by the recruitment of the preassembled U4atac/U6atac.U5 tri-snRNP to the U12-type prespliceosome. Although all 5 snRNPs are present, the precatalytic spliceosome is catalytically inactive. The precatalytic spliceosome includes many proteins in addition to those found in the U11, U12 and U4atac/U6atac.U5 snRNPs.

A spliceosomal complex that is formed by the cooperative binding of the heterodimeric U11/U12 snRNP to the 5' splice site and the branch point sequence. The U12-type prespliceosome includes many proteins in addition to those found in the U11/U12 heterodimeric snRNPs. Commitment to a given pair of 5' and 3' splice sites occurs at the time of prespliceosome formation.

Any spliceosomal complex that forms during the splicing of a messenger RNA primary transcript to excise an intron; the series of U12-type spliceosomal complexes is involved in the splicing of the majority of introns that contain atypical AT-AC terminal dinucleotides, as well as other non-canonical introns. The entire splice site signal, not just the terminal dinucleotides, is involved in determining which spliceosome utilizes the site.

A ribonucleoprotein complex that contains small nuclear RNA U1, a heptameric ring of Sm proteins, as well as several proteins that are unique to the U1 snRNP, most of which remain associated with the U1 snRNA both while the U1 snRNP is free or assembled into a series of spliceosomal complexes.

A ribonucleoprotein complex that contains small nuclear RNA U2, a heptameric ring of Sm proteins, as well as several proteins that are unique to the U2 snRNP, most of which remain associated with the U2 snRNA both while the U2 snRNP is free or assembled into a series of spliceosomal complexes.

A spliceosomal complex that is formed by the displacement of the U1 and U4 snRNPs from the precatalytic spliceosome; the U2, U5 and U6 snRNPs remain associated with the mRNA. This complex, sometimes called the activated spliceosome, is the catalytically active form of the spliceosome, and includes many proteins in addition to those found in the U2, and U5 and U6 snRNPs.

A spliceosomal complex that contains the U2, U5 and U6 snRNPs bound to a splicing intermediate in which the first catalytic cleavage of the 5' splice site has occurred. The precise subunit composition differs significantly from that of the catalytic step 1, or activated, spliceosome, and includes many proteins in addition to those found in the U2, U5 and U6 snRNPs.

A spliceosomal complex that is formed following the release of the spliced product from the post-spliceosomal complex and contains the excised intron and the U2, U5 and U6 snRNPs.

A spliceosomal complex that is formed following the second splicing event and contains the spliced product, the excised intron, and three snRNPs, U5, U2 and U6.

A spliceosomal complex that is formed by the recruitment of the preassembled U4/U6.U5 tri-snRNP to the prespliceosome. Although all 5 snRNPs are present, the precatalytic spliceosome is catalytically inactive. The precatalytic spliceosome includes many proteins in addition to those found in the U1, U2 and U4/U6.U5 snRNPs.

A spliceosomal complex that is formed by association of the 5' splice site with the U1 snRNP, while the branch point sequence is recognized by the U2 snRNP. The prespliceosome includes many proteins in addition to those found in the U1 and U2 snRNPs. Commitment to a given pair of 5' and 3' splice sites occurs at the time of prespliceosome formation.

Any spliceosomal complex that forms during the splicing of a messenger RNA primary transcript to excise an intron that has canonical consensus sequences near the 5' and 3' ends.

A ribonucleoprotein complex that contains small nuclear RNA U4, a heptameric ring of Sm proteins, as well as several proteins that are unique to the U4 snRNP, most of which remain associated with the U4 snRNA both while the U4 snRNP is free or assembled into the U4/U6 snRNP or into a series of spliceosomal complexes.

A ribonucleoprotein complex that contains the extensively base paired small nuclear RNAs U4 and U6, a heptameric ring of Sm proteins associated with U4, the Lsm2-8 heptameric ring complex associated with U6, as well as several proteins that are unique to the U4 snRNP or U6 snRNPs, some of which remain associated with the U4/U6 snRNA both while the U4 snRNP is free or assembled into a series of spliceosomal complexes.

A ribonucleoprotein complex that is formed by the association of the U4/U6 and U5 snRNPs.

A ribonucleoprotein complex that contains small nuclear RNA U4atac, a heptameric ring of Sm proteins, as well as several proteins that are unique to the U4atac snRNP, most of which remain associated with the U4atac snRNA both while the U4atac snRNP is free or assembled into the U4atac/U6atac complex or into a series of spliceosomal complexes.

A ribonucleoprotein complex that contains the extensively base paired small nuclear RNAs U4atac and U6atac, a heptameric ring of Sm proteins associated with U4atac, the Lsm2-8 heptameric ring complex associated with U6atac, as well as several proteins that are unique to the U4atac snRNP or U6atac snRNPs, some of which remain associated with the U4atac/U6atac snRNA both while the U4atac snRNP is free or assembled into a series of spliceosomal complexes.

A spliceosomal snRNP complex that is formed by the association of the U4atac/U6atac and U5 snRNPs.

A ribonucleoprotein complex that contains small nuclear RNA U5, a heptameric ring of Sm proteins, as well as several proteins that are unique to the U5 snRNP, most of which remain associated with the U5 snRNA both while the U5 snRNP is free or assembled into a series of spliceosomal complexes.

A ribonucleoprotein complex that contains small nuclear RNA U6, the Lsm2-8 heptameric ring complex, as well as several proteins that are unique to the U6 snRNP, most of which remain associated with the U6 snRNA both while the U6 snRNP is free or assembled into the U4/U6 snRNP or into a series of spliceosomal complexes.

A ribonucleoprotein complex that contains small nuclear RNA U6atac, the Lsm2-8 heptameric ring complex, as well as several proteins that are unique to the U6atac snRNP, most of which remain associated with the U6atac snRNA both while the U6atac snRNP is free or assembled into the U4atac/U6atac snRNP or into a series of spliceosomal complexes.

A ribonucleoprotein complex that contains the U7 snRNA and is required for the 3'-end processing of replication-dependent histone pre-mRNAs.