Influenzavirus replikere deres RNA-genom i association med værts-celle kromatin. Her præsenterer vi en metode til at rense intakte...
A previously unrecognized mechanism through which large ribonucleoprotein (megaRNP) granules exit the nucleus is by budding through the nuclear envelope (NE). This mechanism is akin to the nuclear egress of herpes-type viruses and is essential for proper synapse development. However, the molecular machinery required to remodel the NE during this process is unknown. Here, we identify Torsin, an AAA-ATPase that in humans is linked to dystonia, as a major mediator of primary megaRNP envelopment during NE budding.
The nucleoprotein of negative-strand RNA viruses forms a major component of the ribonucleoprotein complex that is responsible for viral transcription and replication. However, the precise role of nucleoprotein in viral RNA transcription and replication is not clear. Here we show that nucleoprotein of influenza A virus is entirely dispensable for replication and transcription of short viral RNA-like templates in vivo, suggesting that nucleoprotein represents an elongation factor for the viral RNA polymerase. We also find that the recruitment of nucleoprotein to nascent ribonucleoprotein complexes during replication of full-length viral genes is mediated through nucleoprotein-nucleoprotein homo-oligomerization in a tail loop-first orientation and is independent of RNA binding. This work demonstrates that nucleoprotein does not regulate the initiation and termination of transcription and replication by the viral polymerase in vivo, and provides new mechanistic insights into the assembly and regulation of
The latest report Trailer Hitch by QY Research added to its database and brings to light the comprehensive study and factual information of global market. The report also provides the global market segmentation based on applications, end-users, technology, and geography. The Trailer Hitch research report offers a comprehensive assessment of the Trailer Hitch market and consists of historical data, scope, significant approaches and statistical data of the global market. Besides these, it also includes anticipated facts that are assessed with the aid of an appropriate set of postulations and techniques.. The report includes rigorous data, in-depth analysis in two ways, namely, quantitative and qualitative, industry professionals inputs and data given by the industry members and industry analysts involved in the complete value cycle. The report features thorough study of important market and their current trends, coupled with respective market segments. Information about the numerous factors and ...
The new Scripps Research Institute study shows flu virus proteins in the act of self-replication. Shown here is the influenza virus, which encapsidates its RNA genome (green) with a viral nucleoprotein (blue); the influenza virus polymerase (orange) reads and copies the RNA genome. In the background is an image of influenza virus ribonucleoprotein complexes observed using cryo-electron microscopy.
Regulates the coordinated translation of type I collagen alpha-1 and alpha-2 mRNAs, CO1A1 and CO1A2. Stabilizes mRNAs through high-affinity binding of a stem-loop structure in their 5 UTR. This regulation requires VIM and MYH10 filaments, and the helicase DHX9 ...
Recognition of the 3′-splice site is a key step in pre-mRNA splicing and accomplished by a dynamic complex comprising splicing factor 1 (SF1) and the U2 snRNP auxiliary factor 65-kDa subunit (U2AF65). Both proteins mediate protein-protein and protein-RNA interactions for cooperative RNA-binding during spliceosome assembly. Here, we report the solution structure of a novel helix-hairpin domain in the N-terminal region of SF1 (SF1NTD). The nuclear magnetic resonance- and small-angle X-ray scattering-derived structure of a complex of the SF1NTD with the C-terminal U2AF homology motif domain of U2AF65 (U2AF65UHM) reveals that, in addition to the known U2AF65UHM-SF1 interaction, the helix-hairpin domain forms a secondary, hydrophobic interface with U2AF65UHM, which locks the orientation of the two subunits. Mutational analysis shows that the helix hairpin is essential for cooperative formation of the ternary SF1-U2AF65-RNA complex. We further show that tandem serine phosphorylation of a conserved ...
Many RNA-associated proteins contain a ribonucleoprotein (RNP) consensus octamer encompassed by a conserved 80 amino acid sequence, termed an RNA recognition motif (RRM). RRM family members contain either one (class I) or multiple (class II) copies of this motif. A class II component of the U1 small nuclear RNP (snRNP), the A protein of U1 snRNP (U1snRNP-A), contains two RRMs (RRM1 and -2), yet has only one binding domain (RRM1) that interacts specifically with stem-loop II of U1 RNA. Quantitative analysis of binding affinities of fragments of U1snRNP-A demonstrates that an 86-amino acid polypeptide is competent to bind to U1 RNA with an affinity comparable to that of the full-length protein (Kd approximately 80 nM). The carboxyl-terminal RRM2 of U1snRNP-A does not bind to U1 RNA and may recognize an unidentified heterologous RNA. It is proposed that class II proteins may function as bridges between RNA components of RNP complexes, such as the spliceosome (Lutz-Freyermuth, 1990). The RNP domain ...
Lucero Rogel. PREP Program. Lab Group: Alan Zahler. PREP Research: The Zahler lab works to investigate the mechanism of RNA splicing by utilizing C. elegans as a model organism. Accurate splicing of pre-mRNA is a critical step in the gene expression pathway in eukaryotes carried out by a large ribonucleoprotein complex known as the spliceosome. The spliceosome consists of 5 RNAs (U1, U2, U4, U5, and U6) that assemble onto the pre-mRNA by recognizing conserved sequence elements that define the beginning and ends of introns, known as 5 and 3 splice sites. To facilitate the interactions between the pre-mRNA and the 5 RNAs, over 150 proteins are employed to aid in the process. Currently in the lab, I am working on elucidating the role of spliceosomal protein SNRP-27 in 5 splice site selection by uncovering differential interactions that a mutant and wild type form of this factor have with the splicing machinery.. Undergraduate Major: Biochemistry and Molecular Biology. Undergraduate Institution: ...
Despite "decades of persistent failure to create life by the spark in the soup method,"1 evolutionary biochemists are still trying to find an exclusively naturalistic explanation for how the first cell developed. Many possible chemical precursors to life have been systematically ruled out by rigorous experiments. What they have found is that the molecules necessary for life are found exclusively within cells that are already living.. One explanation proposed by evolutionists was the "RNA world" hypothesis, which holds that the first molecules to have spontaneously materialized in an ancient chemical soup were RNAs.2 This has met with too many obstacles to remain viable, so an embellishment to the RNA world was recently proposed by Thomas Cech in the journal Cell.3 He suggested that the first molecules to evolve toward life were ribonucleoproteins (RNPs), molecules made partly of RNA and partly of protein.. In nature, RNPs are found only inside cells. They have specific shapes, sizes, and ...
The protein encoded by this gene plays a role in ribosomal protein transport and in the assembly of the 5S ribonucleoprotein particle (5S RNP). The encoded protein also may be involved in NOD2-mediated NF-kappaB signaling. [provided by RefSeq, Jul 2016 ...
Our results indicate that disturbed THOC1 and ALY expression are associated with tumorogenesis. Overexpression of THOC1 has previously been correlated to the grade of invasiveness in breast tumor, and also a relationship between the levels of this protein in non-small lung cancers has been suggested [12, 15]. This study shows that not only the expression of THOC1, but also that of THO/TREX complex is upregulated in breast cancer cells. Moreover, new links between the expression of THOC1 and different tumors were found. THOC1 mRNA and protein levels are up-regulated in ovarian, and lung tumors and down-regulated in those of testis and skin. Interestingly, we show that ALY, another mRNP biogenesis factor is highly detected in proliferative cells and overexpressed in a broad range of tumors. The different pattern of expression of THOC1 and ALY in tumors could indicate a different relevance for each factor in tumorogenesis. Nevertheless, since many genes are differentially expressed in cancer ...
Small ribonucleoproteins (RNPs) are essential components of all cells. Eukaryotic gene expression requires a constellation of small non-coding RNP particles tha...
Engineered to support up to a maximum load of 5,000 lb, this 10 drop ball mount is ideal for multiple oversized towing applications. It is constructed with carbon steel for extra strength and durability in all types of rough climates. Ideal for anything from towing yachts, to jeeps and other large vehicles. Heavy duty,
1L3K: Correlated alternative side chain conformations in the RNA-recognition motif of heterogeneous nuclear ribonucleoprotein A1.
Complete information for SLC6A8 gene (Protein Coding), Solute Carrier Family 6 Member 8, including: function, proteins, disorders, pathways, orthologs, and expression. GeneCards - The Human Gene Compendium
Complete information for SLC6A8 gene (Protein Coding), Solute Carrier Family 6 Member 8, including: function, proteins, disorders, pathways, orthologs, and expression. GeneCards - The Human Gene Compendium
Intermodal transportation requires specialized rail equipment which is, on occasion, too specialized. To allow more flexibility in loading containers and trailers at terminals all-purpose spine cars were developed. These cars can be configured to allow loading of trailers of varying lengths, from 28 pups to 53 high capacity units. With the trailer hitches collapsed containers can also be loaded. 40, 45 48 and 53 containers call all be accommodated on these cars as well as 20 models provided they are mounted to a chassis. The prototype for our model is based on a Trinity-built car owned by the TTX Company. These 70-ton cars (TTX class RAF30A) numbered TTRX 360817-361116 first appeared on the rails in the late 1990s. The Athearn model is faithful to the prototype allowing modelers to load a variety of trailers and containers ...
For Sale 1987 Dodge Power Ram W250 4x4. rebuilt 318 with low miles, 727 auto trans, 4x4, good tires, bed liner, class 3 trailer hitch, newer...
TY - JOUR. T1 - The Ro ribonucleoprotein particle. T2 - Induction of autoantibodies and the detection of Ro RNAs among species. AU - Mamula, Mark J.. AU - OBrien, Charles A.. AU - Harley, John B.. AU - Hardin, John A.. PY - 1989. Y1 - 1989. N2 - High titers of autoantibody specific for the Ro(SSA) ribonucleoprotein are frequently found in patients with systemic lupus erythematosus and Sjogrens syndrome. In this study we have analyzed the immune responses to the Ro particle when utilized as an immunogen in animal hosts. Anti-Ro autoantibodies which bound autologous Ro ribonucleoprotein particles were induced in rabbits. In immunodiffusion studies using crude rabbit tissue extracts, the rabbit antibody made a precipitin line of identity with a prototype human anti-Ro serum. In solid-phase assays, the human autoimmune serum and the antigen-induced rabbit serum competed for similar or overlapping epitopes on the Ro particle. The rabbit and human sera precipitated the four Ro RNAs from human cells ...
Balbiani ring (BR) granules are premessenger ribonucleoprotein particles (RNPs) generated in giant chromosomal puffs, the BRs, in the larval salivary glands of the dipteran chironomus tentans. Monoclonal antibodies were raised against nuclear proteins collected on a single-stranded-DNA-agarose affinity column, and two of them were used to identify RNA-binding proteins in BR granules. First, in Western blots (immunoblots), one of the antibodies recognized a 36-kDa protein and the other recognized a 45-KDa protein. Second, both antibodies bound to the BRs in immunocytological experiments. It was shown in cross-linking experiments that the two proteins are associated with heterogeneous nuclear RNP (hnRNP) complexes extracted from C. tentans nuclei. By immunoelectron microscopy of isolated and partly unfolded BR RNPs, it was specifically demonstrated that the BR granules contain the two proteins and, in addition, that both proteins are distributed frequently along the RNP fiber of the particles. ...
In higher eukaryotes, the polypyrimidine-tract (Py-tract) adjacent to the 3 splice site is recognized by several proteins, including the essential splicing factor U2AF65, the splicing regulator Sex-lethal (Sxl), and polypyrimidine tract-binding protein (PTB), whose function is unknown. Iterative in vitro genetic selection was used to show that these proteins have distinct sequence preferences. The uridine-rich degenerate sequences selected by U2AF65 are similar to those present in the diverse array of natural metazoan Py-tracts. In contrast, the Sxl-consensus is a highly specific sequence, which can help explain the ability of Sxl to regulate splicing of transformer pre-mRNA and autoregulate splicing of its own pre-mRNA. The PTB-consensus is not a typical Py-tract; it can be found in certain alternatively spliced pre-mRNAs that undergo negative regulation. Here it is shown that PTB can regulate alternative splicing by selectively repressing 3 splice sites that contain a PTB-binding site. ...
Q. I am towing a roughly 3,000-pound 1999 21-foot tandem-axle hybrid travel trailer with a 2005 Chevrolet Trailblazer. How important is it for the travel trailers 400-pound hitch to remain level after I put on the weight distributing bars? Is this mostly an issue of suspension and/or tire wear on the trailer? Is a few inches off level at the coupler a big deal?. - A.B., via e-mail. A. Im guessing that by "remain level" you are referring to the back end of the Trailblazer sagging a bit under the weight of the trailer hitch. If that happens, you dont have the hitch adjusted properly. Yes, it can be a big deal because if the Trailblazer back end is a few inches low, that means the front end is a bit high, and that means your steering geometry can be thrown off. It may not be obvious at first, but get into a squirrely driving situation and you may have a handful of excitement in a big hurry.. The bars will need to be tighter to better distribute some of that hitch weight to the tow rigs front ...
Zheng X, Cho S, Moon H, Loh TJ, Oh HK, Green MR, Shen H. Polypyrimidine tract binding protein inhibits IgM pre-mRNA splicing by diverting U2 snRNA base-pairing away from the branch point. RNA. 2014 Apr; 20(4):440-6 ...
We have purified the yeast U5 and U6 pre-mRNA splicing small nuclear ribonucleoproteins (snRNPs) by affinity chromatography and analyzed the associated polypeptides by mass spectrometry. The yeast U5 snRNP is composed of the two variants of U5 snRNA, six U5-specific proteins and the 7 proteins of the canonical Sm core. The U6 snRNP is composed of the U6 snRNA, Prp24, and the 7 Sm-Like (LSM) proteins. Surprisingly, the yeast DEAD-box helicase-like protein Prp28 is stably associated with the U5 snRNP, yet is absent from the purified U4/U6.U5 snRNR A novel yeast U5 and four novel yeast U4/U6.U5 snRNP polypeptides were characterized by genetic and biochemical means to demonstrate their involvement in the pre-mRNA splicing reaction. We also show that, unlike the human tri-snRNP, the yeast tri-snRNP dissociated upon addition of ATP or dATP. ...
A complex composed of RNA of the small nuclear RNA (snRNA) class and protein, found in the nucleus of a eukaryotic cell. These are typically named after the snRNA(s) they contain, e.g. U1 snRNP or U4/U6 snRNP. Many, but not all, of these complexes are involved in splicing of nuclear mRNAs. [GOC:krc, GOC:mah, ISBN:0879695897]
Ribosome biogenesis factor. Involved in nucleolar processing of pre-18S ribosomal RNA. Involved in small subunit (SSU) pre-rRNA processing at sites A, A0, 1 and 2b. Required for optimal pre-ribosomal RNA transcription by RNA polymerase. May be a transcriptional regulator. Acts as a positive regulator of HIVEP1.
Precursor mRNA (pre-mRNA) splicing is catalyzed by a large ribonucleoprotein complex known as the spliceosome. Numerous studies have indicated that aberrant splicing patterns or mutations in spliceosome components, including the splicing factor 3b subunit 1 (SF3B1), are associated with hallmark cancer phenotypes. This has led to the identification and development of small molecules with spliceosome-modulating activity as potential anticancer agents. Jerantinine A (JA) is a novel indole alkaloid which displays potent anti-proliferative activities against human cancer cell lines by inhibiting tubulin polymerization and inducing G2/M cell cycle arrest. Using a combined pooled-genome wide shRNA library screen and global proteomic profiling, we showed that JA targets the spliceosome by up-regulating SF3B1 and SF3B3 protein in breast cancer cells. Notably, JA induced significant tumor-specific cell death and a significant increase in unspliced pre-mRNAs. In contrast, depletion of endogenous SF3B1 ...
Synthesis of proteins is performed by the ribosome, a large ribonucleoprotein complex. Apart from the ribosome, numerous protein factors participate in this process. Elongation factor 2 (eEF2) is one of these factors. eEF2 is an essential protein with a mol. mass of about 100 kDa. The amino acid sequence of eEF2 is highly conserved in different organisms. eEF2 from S. cerevisiae contains 842 amino acids. The role of eEF2 in protein synthesis is to participate in the translocation of tRNAs from the A- and P-sites on the ribosome to the P- and E-sites. This movement of tRNAs is accompanied by a simultaneous movement of mRNA by one codon. eEF2 consists of six domains referred to as domains G, G′ and II-V, belongs to the G-protein super-family and possesses all structural motifs characterizing proteins in this family. eEF2 binds to the ribosome in complex with GTP. After GTP hydrolysis and translocation, it leaves the ribosome bound to GDP. The rate of protein synthesis in the cell can be ...
cytoplasm, cytoplasmic ribonucleoprotein granule, cytosol, exon-exon junction complex, nucleus, perinuclear region of cytoplasm, polysome, telomeric DNA binding, animal organ regeneration, liver development
When recombinant La protein was added to these reactions at 50 nM, the precursor transcript remained unprocessed after a 60-min incubation (Fig. 1B, compare lanes 1 and 2). Reactions with unfractionated HeLa S100 containing endogenous La at 50 nM (2 pmol) also yielded primarily unprocessed precursor (lane 3), a finding consistent with previous results (45).. Because the lack of processing in S100 might be due to an inhibitory protein other than La, we performed reactions that were immunodepleted of La and after repletion with purified La (Fig. 1C). Depletion of La led to the tRNAi Met-size transcript as the major product (lane 2). Most importantly, protection of pre-tRNA from processing could be recovered by adding highly purified La back into the immunodepleted reaction mixture (lane 3). In contrast to depletion with anti-La, mock depletion with normal human immunoglobulin G produced unprocessed pre-tRNAi Met (not shown). This established that La is inhibitory to pre-tRNAi Metprocessing at the ...
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The PDB archive contains information about experimentally-determined structures of proteins, nucleic acids, and complex assemblies. As a member of the wwPDB, the RCSB PDB curates and annotates PDB data according to agreed upon standards. The RCSB PDB also provides a variety of tools and resources. Users can perform simple and advanced searches based on annotations relating to sequence, structure and function. These molecules are visualized, downloaded, and analyzed by users who range from students to specialized scientists.
The Laboratory of Ribonucleoprotein Biochemistry, led by Dr. J. Robert Hogg, studies how RNAs attain unique functions in the cell by their intimate associations with proteins as part of ribonucleoprotein complexes (RNPs). In particular, Dr. Hoggs focus has been on quality control and RNA surveillance ...
SSB antibody [3H9] (Sjogren syndrome antigen B (autoantigen La)) for ICC/IF, IHC-P, IP, WB. Anti-SSB mAb (GTX83560) is tested in Human, Dog samples. 100% Ab-Assurance.
Intracellular Redistribution of Truncated La Protein Produced by Poliovirus 3Cpro-Mediated Cleavage: The La autoantigen (also known as SS-B), a cellular RNA bin
Watkins, N. J.; Segault, V.; Carpentier, B.; Nottrott, S.; Fabrizio, P.; Bachi, A.; Wilm, M.; Rosbash, M.; Branlant, C.; Luehrmann, R.: A common core RNP structure shared between the small nuclear box C/D RNPs and the spliceosomal U 4 snRNP. Cell 103, pp. 457 - 466 (2000 ...
Churchill Car Insurance Problem?. Had accident which was my fault in Nov 08, hit a van in rear that stopped suddenly going through a roundabout (less than 5mph) and his trailer hitch ball went into my radiator and damaged the hood, grill and radiator. Car was 1996 Honda in very reasonable condition, MOTd and all in good service despite its 125,000 mileage, new tyres, exhaust, battery, and clean throughout. Had fully comprehensive insurance with £50 deductable, loaner car and legal support so paid to be protected. When car was collected from accident, collecting garage said at that time that due to the mileage my car would not be repaired. However it took 5 to 6 weeks for the insurance examiner to determine that my car was beyond repair, so I did without a car all that time. Despite repeated phone calls to them, they never called me back as their examiner was on holiday. Then when we finally agree that a price of £500 for my car in January 08 and that took some haggling, the cheque never and ...
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The movement of genetic materials, such as RNA and ribosomes, from the nucleus to the cytoplasm is a critical component in a cells ability to make the proteins necessary for essential biological functions. Until now, it ...
Name: ______________________________________ Date: ________________________ Student Exploration: RNA and Protein SynthesisVocabulary: amino…
Попробуйте оправдать игровые автоматы Вокруг киберпространства, которое вы покидаете, вы услышите, как веб-сайты дают вам возможность сыграть в онлайн-слоты на мертвую версию. Если вы выполнили загрузку «Кассино», то вы точно поймете, что нужно выиграть в следующих четырех казино. В эдикте, чтобы исключить очередное разочарование в слотах, вы можете захотеть получить авто, которое завещает гарантированную плату, сопоставимую с тем, что на самом деле говорится. Осуществление выставки дает вам возможность убедиться, что мерчендайзинг был просто ...
Попробуйте оправдать игровые автоматы Вокруг киберпространства, которое вы покидаете, вы услышите, как веб-сайты дают вам возможность сыграть в онлайн-слоты на мертвую версию. Если вы выполнили загрузку «Кассино», то вы точно поймете, что нужно выиграть в следующих четырех казино. В эдикте, чтобы исключить очередное разочарование в слотах, вы можете захотеть получить авто, которое завещает гарантированную плату, сопоставимую с тем, что на самом деле говорится. Осуществление выставки дает вам возможность убедиться, что мерчендайзинг был просто ...
TY - JOUR. T1 - Reconstitution of nucleoprotein complexes with mammalian heterogeneous nuclear ribonucleoprotein (hnRNP) core proteins. AU - Pullman, J. M.. AU - Martin, T. E.. PY - 1983/1/1. Y1 - 1983/1/1. N2 - Newly transcribed heterogeneous nuclear RNA (hnRNA) in the eukaryotic cell nucleus is bound by proteins, giving rise to large ribonucleoprotein (RNP) fibrils with an inherent substructure consisting largely of relatively homogeneous ~20-nm 30S particles, which contain core polypeptides of 34,000-38,000 mol wt. To determine whether this group of proteins was sufficient for the assembly of the native beaded nucleoprotein structure, we dissociated 30S hnRNP purified from mouse ascites cells into their component proteins and RNA by treatment with the ionic detergent sodium deoxycholate and then reconstituted this complex by addition of Triton X-100 to sequester the deoxycholate. Dissociation and reassembly were assayed by sucrose gradient centrifugation, monitoring UV absorbance, protein ...
Shop Heterogeneous nuclear ribonucleoproteins ELISA Kit, Recombinant Protein and Heterogeneous nuclear ribonucleoproteins Antibody at MyBioSource. Custom ELISA Kit, Recombinant Protein and Antibody are available.
The multifunctional β-galactoside-binding protein galectin-3 is found in many distinct subcellular compartments including the cell nucleus. Expression and distribution of galectin-3 between the cell nucleus and the cytosol changes during cell differentiation and cancer development. Nuclear functions of galectin-3 and how they contribute to tumorigenesis are not understood. In order to identify nuclear galectin-3 interaction partners, we used affinity chromatography and co-immunoprecipitation. Spatial proximity in the nucleus was assessed by immunofluorescence and proximity ligation assay. We also investigated the function of galectin-3 on mRNA-export by fluorescence in situ hybridization and on mRNA-processing by RNA-sequencing. The heterogeneous ribonucleoprotein particle component hnRNPA2B1 was identified as a novel galectin-3 binding protein that associates with the lectin in a lactose-dependent manner in the cell nucleus. Specific individual depletion of galectin-3 does not affect the mRNA
Many eukaryotic cells contain large ribonucleoprotein particles in the cytoplasm known as vaults. The vault complex comprises the major vault protein (MVP), two minor vault proteins (VPARP and TEP1), and a variety of small untranslated RNA molecules. Given the association with the nuclear membrane and the location within the cell, vaults are thought to play roles in intracellular and nucleocytoplasmic transport processes. Also, given that the structure and protein composition are highly conserved among species, it is believed that the roles vault plays are integral to eukaryotic function. While vault proteins appear to be present in a variety of organisms, vaults isolated from higher eukaryotes contain a small portion, about 5%, of small untranslated RNAs called vault RNAs, or vtRNAs. These RNA molecules are polymerase III transcripts. In addition, a study, using cryo-electron microscopy, has determined that vtRNAs are found close to the end caps of vaults. This positioning of the RNA indicates ...
The proximal promoter of the hypoxia inducible factor 1 alpha (HIF-1α) gene contains a poly-purine/poly-pyrimidine (pPu/pPy) tract, which has been shown to affect 9..
Small nuclear ribonucleoprotein-associated protein B and B is a protein that in humans is encoded by the SNRPB gene. The protein encoded by this gene is one of several nuclear proteins that are found in common among U1, U2, U4/U6, and U5 small ribonucleoprotein particles (snRNPs). These snRNPs are involved in pre-mRNA splicing, and the encoded protein may also play a role in pre-mRNA splicing or snRNP structure. Autoantibodies from patients with systemic lupus erythematosus frequently recognize epitopes on the encoded protein. Two transcript variants encoding different isoforms (B and B) have been found for this gene.
Polypyrimidine Tract Binding Protein (PTB) is an intensely studied RNA binding protein involved in several post-transcriptional regulatory events of gene expression. Initially described as a pre-mRNA splicing regulator, PTB is now widely accepted as a multifunctional protein shuttling between nucleus and cytoplasm. Accordingly, PTB can interact with selected RNA targets, structural elements and proteins. There is increasing evidence that PTB and its paralog PTBP2 play a major role as repressors of alternatively spliced exons, whose transcription is tissue-regulated. In addition to alternative splicing, PTB is involved in almost all steps of mRNA metabolism, including polyadenylation, mRNA stability and initiation of protein translation. Furthermore, it is well established that PTB recruitment in internal ribosome entry site (IRES) activates the translation of picornaviral and cellular proteins. Detailed studies of the structural properties of PTB have contributed to our understanding of the mechanism of