A family of ribonucleoproteins that were originally found as proteins bound to nascent RNA transcripts in the form of ribonucleoprotein particles. Although considered ribonucleoproteins they are primarily classified by their protein component. They are involved in a variety of processes such as packaging of RNA and RNA TRANSPORT within the nucleus. A subset of heterogeneous-nuclear ribonucleoproteins are involved in additional functions such as nucleocytoplasmic transport (ACTIVE TRANSPORT, CELL NUCLEUS) of RNA and mRNA stability in the CYTOPLASM.
Nuclear nonribosomal RNA larger than about 1000 nucleotides, the mass of which is rapidly synthesized and degraded within the cell nucleus. Some heterogeneous nuclear RNA may be a precursor to mRNA. However, the great bulk of total hnRNA hybridizes with nuclear DNA rather than with mRNA.
Complexes of RNA-binding proteins with ribonucleic acids (RNA).
A class of closely related heterogeneous-nuclear ribonucleoproteins of approximately 34-40 kDa in size. Although they are generally found in the nucleoplasm, they also shuttle between the nucleus and the cytoplasm. Members of this class have been found to have a role in mRNA transport, telomere biogenesis and RNA SPLICING.
A group of closely-related heterogeneous-nuclear ribonucleoproteins that are involved in pre-mRNA splicing.
Highly conserved nuclear RNA-protein complexes that function in RNA processing in the nucleus, including pre-mRNA splicing and pre-mRNA 3'-end processing in the nucleoplasm, and pre-rRNA processing in the nucleolus (see RIBONUCLEOPROTEINS, SMALL NUCLEOLAR).
A group of closely related heterogeneous-nuclear ribonucleoproteins of approximately 41-43 kDa in size found in the cell nucleus. Members of this class have been implicated in a variety of processes including splicing, polyadenylation, and nuclear retention of RNA.
Proteins that bind to RNA molecules. Included here are RIBONUCLEOPROTEINS and other proteins whose function is to bind specifically to RNA.
A heterogeneous-nuclear ribonucleoprotein found in the CELL NUCLEUS and the CYTOPLASM. Heterogeneous-nuclear ribonucleoprotein K has been implicated in the regulation of gene expression at nearly all levels: GENETIC TRANSCRIPTION; mRNA processing (RNA PROCESSING, POST-TRANSCRIPTIONAL), mRNA transport, mRNA stability, and translation (TRANSLATION, GENETIC). The hnRNP protein has a strong affinity for polypyrimidine-rich RNA and for single-stranded polypyrimidine-rich DNA. Multiple hnRNP K protein isoforms exist due to alternative splicing and display different nucleic-acid-binding properties.
The ultimate exclusion of nonsense sequences or intervening sequences (introns) before the final RNA transcript is sent to the cytoplasm.
RNA transcripts of the DNA that are in some unfinished stage of post-transcriptional processing (RNA PROCESSING, POST-TRANSCRIPTIONAL) required for function. RNA precursors may undergo several steps of RNA SPLICING during which the phosphodiester bonds at exon-intron boundaries are cleaved and the introns are excised. Consequently a new bond is formed between the ends of the exons. Resulting mature RNAs can then be used; for example, mature mRNA (RNA, MESSENGER) is used as a template for protein production.
Proteins involved in the process of transporting molecules in and out the cell nucleus. Included here are: NUCLEOPORINS, which are membrane proteins that form the NUCLEAR PORE COMPLEX; KARYOPHERINS, which carry molecules through the nuclear pore complex; and proteins that play a direct role in the transport of karyopherin complexes through the nuclear pore complex.
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
The protein components that constitute the common core of small nuclear ribonucleoprotein particles. These proteins are commonly referred as Sm nuclear antigens due to their antigenic nature.
A distinct subnuclear domain enriched in splicesomal snRNPs (RIBONUCLEOPROTEINS, SMALL NUCLEAR) and p80-coilin.
Organelles in which the splicing and excision reactions that remove introns from precursor messenger RNA molecules occur. One component of a spliceosome is five small nuclear RNA molecules (U1, U2, U4, U5, U6) that, working in conjunction with proteins, help to fold pieces of RNA into the right shapes and later splice them into the message.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Short chains of RNA (100-300 nucleotides long) that are abundant in the nucleus and usually complexed with proteins in snRNPs (RIBONUCLEOPROTEINS, SMALL NUCLEAR). Many function in the processing of messenger RNA precursors. Others, the snoRNAs (RNA, SMALL NUCLEOLAR), are involved with the processing of ribosomal RNA precursors.
A complex of proteins that assemble the SNRNP CORE PROTEINS into a core structure that surrounds a highly conserved RNA sequence found in SMALL NUCLEAR RNA. They are found localized in the GEMINI OF COILED BODIES and in the CYTOPLASM. The SMN complex is named after the Survival of Motor Neuron Complex Protein 1, which is a critical component of the complex.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the U4-U6 snRNP along with the U5 snRNP preassemble into a single 25S particle that binds to the U1 and U2 snRNPs and the substrate to form mature SPLICEOSOMES. There is also evidence for the existence of individual U4 or U6 snRNPs in addition to their organization as a U4-U6 snRNP.
Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.
A multifunctional protein that is both a DEAD-box RNA helicase and a component of the SMN protein complex.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Electrophoresis in which a second perpendicular electrophoretic transport is performed on the separate components resulting from the first electrophoresis. This technique is usually performed on polyacrylamide gels.
A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the U1 snRNP along with other small nuclear ribonucleoproteins (U2, U4-U6, and U5) assemble into SPLICEOSOMES that remove introns from pre-mRNA by splicing. The U1 snRNA forms base pairs with conserved sequence motifs at the 5'-splice site and recognizes both the 5'- and 3'-splice sites and may have a fundamental role in aligning the two sites for the splicing reaction.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the U5 snRNP along with U4-U6 snRNP preassemble into a single 25S particle that binds to the U1 and U2 snRNPs and the substrate to form SPLICEOSOMES.
A species of newt in the Salamandridae family in which the larvae transform into terrestrial eft stage and later into an aquatic adult. They occur from Canada to southern United States. Viridescens refers to the greenish color often found in this species.
A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the U2 snRNP along with other small nuclear ribonucleoproteins (U1, U4-U6, and U5) assemble into SPLICEOSOMES that remove introns from pre-mRNA by splicing. The U2 snRNA forms base pairs with conserved sequence motifs at the branch point, which associates with a heat- and RNAase-sensitive factor in an early step of splicing.
Proteins conjugated with nucleic acids.
Endogenous tissue constituents that have the ability to interact with AUTOANTIBODIES and cause an immune response.
Enzymes that catalyze the methylation of arginine residues of proteins to yield N-mono- and N,N-dimethylarginine. This enzyme is found in many organs, primarily brain and spleen.
A group of disorders marked by progressive degeneration of motor neurons in the spinal cord resulting in weakness and muscular atrophy, usually without evidence of injury to the corticospinal tracts. Diseases in this category include Werdnig-Hoffmann disease and later onset SPINAL MUSCULAR ATROPHIES OF CHILDHOOD, most of which are hereditary. (Adams et al., Principles of Neurology, 6th ed, p1089)
Small RNAs found in the cytoplasm usually complexed with proteins in scRNPs (RIBONUCLEOPROTEINS, SMALL CYTOPLASMIC).
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
A SMN complex protein that is essential for the function of the SMN protein complex. In humans the protein is encoded by a single gene found near the inversion telomere of a large inverted region of CHROMOSOME 5. Mutations in the gene coding for survival of motor neuron 1 protein may result in SPINAL MUSCULAR ATROPHIES OF CHILDHOOD.
Post-transcriptional biological modification of messenger, transfer, or ribosomal RNAs or their precursors. It includes cleavage, methylation, thiolation, isopentenylation, pseudouridine formation, conformational changes, and association with ribosomal protein.
Use for nucleic acid precursors in general or for which there is no specific heading.
Nucleolar RNA-protein complexes that function in pre-ribosomal RNA processing.
Within most types of eukaryotic CELL NUCLEUS, a distinct region, not delimited by a membrane, in which some species of rRNA (RNA, RIBOSOMAL) are synthesized and assembled into ribonucleoprotein subunits of ribosomes. In the nucleolus rRNA is transcribed from a nucleolar organizer, i.e., a group of tandemly repeated chromosomal genes which encode rRNA and which are transcribed by RNA polymerase I. (Singleton & Sainsbury, Dictionary of Microbiology & Molecular Biology, 2d ed)
A protein that has been shown to function as a calcium-regulated transcription factor as well as a substrate for depolarization-activated CALCIUM-CALMODULIN-DEPENDENT PROTEIN KINASES. This protein functions to integrate both calcium and cAMP signals.
Enzymes that catalyze the methylation of amino acids after their incorporation into a polypeptide chain. S-Adenosyl-L-methionine acts as the methylating agent. EC 2.1.1.
Antibodies that react with self-antigens (AUTOANTIGENS) of the organism that produced them.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
Serologic tests in which a positive reaction manifested by visible CHEMICAL PRECIPITATION occurs when a soluble ANTIGEN reacts with its precipitins, i.e., ANTIBODIES that can form a precipitate.
A chronic, relapsing, inflammatory, and often febrile multisystemic disorder of connective tissue, characterized principally by involvement of the skin, joints, kidneys, and serosal membranes. It is of unknown etiology, but is thought to represent a failure of the regulatory mechanisms of the autoimmune system. The disease is marked by a wide range of system dysfunctions, an elevated erythrocyte sedimentation rate, and the formation of LE cells in the blood or bone marrow.
The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.
The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
A process whereby multiple RNA transcripts are generated from a single gene. Alternative splicing involves the splicing together of other possible sets of EXONS during the processing of some, but not all, transcripts of the gene. Thus a particular exon may be connected to any one of several alternative exons to form a mature RNA. The alternative forms of mature MESSENGER RNA produce PROTEIN ISOFORMS in which one part of the isoforms is common while the other parts are different.
Established cell cultures that have the potential to propagate indefinitely.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)
The aggregation of soluble ANTIGENS with ANTIBODIES, alone or with antibody binding factors such as ANTI-ANTIBODIES or STAPHYLOCOCCAL PROTEIN A, into complexes large enough to fall out of solution.
The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.
A group of adenine ribonucleotides in which the phosphate residues of each adenine ribonucleotide act as bridges in forming diester linkages between the ribose moieties.
The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.
'Nerve tissue proteins' are specialized proteins found within the nervous system's biological tissue, including neurofilaments, neuronal cytoskeletal proteins, and neural cell adhesion molecules, which facilitate structural support, intracellular communication, and synaptic connectivity essential for proper neurological function.
Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.
The sum of the weight of all the atoms in a molecule.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
Ribonucleic acid that makes up the genetic material of viruses.
A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.
A genus of CRUSTACEA of the order ANOSTRACA, found in briny pools and lakes and often cultured for fish food. It has 168 chromosomes and differs from most crustaceans in that its blood contains hemoglobin.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.

Arginine methylation and binding of Hrp1p to the efficiency element for mRNA 3'-end formation. (1/856)

Hrp1p is a heterogeneous ribonucleoprotein (hnRNP) from the yeast Saccharomyces cerevisiae that is involved in the cleavage and polyadenylation of the 3'-end of mRNAs and mRNA export. In addition, Hrplp is one of several RNA-binding proteins that are posttranslationally modified by methylation at arginine residues. By using functional recombinant Hrp1p, we have identified RNA sequences with specific high affinity binding sites. These sites correspond to the efficiency element for mRNA 3'-end formation, UAUAUA. To examine the effect of methylation on specific RNA binding, purified recombinant arginine methyltransferase (Hmt1p) was used to methylate Hrp1p. Methylated Hrp1p binds with the same affinity to UAUAUA-containing RNAs as unmethylated Hrpl p indicating that methylation does not affect specific RNA binding. However, RNA itself inhibits the methylation of Hrp1p and this inhibition is enhanced by RNAs that specifically bind Hrpl p. Taken together, these data support a model in which protein methylation occurs prior to protein-RNA binding in the nucleus.  (+info)

Heterogeneous nuclear ribonucleoprotein D0B is a sequence-specific DNA-binding protein. (2/856)

Complement receptor 2 (CR2) is important in the regulation of the B lymphocyte response; the regulation of its expression is therefore of central importance. We recently reported that a 42 kDa heterogeneous nuclear ribonucleoprotein (hnRNP) is involved in the transcriptional regulation of the human CR2 gene [Tolnay, Lambris and Tsokos (1997) J. Immunol. 159, 5492-5501]. We cloned the cDNA encoding this protein and found it to be identical with hnRNP D0B, a sequence-specific RNA-binding protein. By using a set of mutated oligonucleotides, we demonstrated that the recombinant hnRNP D0B displays sequence specificity for double-stranded oligonucleotide defined by the CR2 promoter. We conducted electrophoretic mobility-shift assays to estimate the apparent Kd of hnRNP D0B for the double-stranded DNA motif and found it to be 59 nM. Interestingly, hnRNP D0B displayed affinities of 28 and 18 nM for the sense and anti-sense strands of the CR2 promoter-defined oligonucleotide respectively. The significantly greater binding affinity of hnRNP D0B for single-stranded DNA than for double-stranded DNA suggests that the protein might melt the double helix. The intranuclear concentration of sequence-specific protein was estimated to be 250-400 nM, indicating that the protein binds to the CR2 promoter in vivo. Co-precipitation of a complex formed in vivo between hnRNP D0B and the TATA-binding protein demonstrates that hnRNP D0B interacts with the basal transcription apparatus. Our results suggest a new physiological role for hnRNP D0B that involves binding to double- and single-stranded DNA sequences in a specific manner and functioning as a transcription factor.  (+info)

hnRNP C and polypyrimidine tract-binding protein specifically interact with the pyrimidine-rich region within the 3'NTR of the HCV RNA genome. (3/856)

Like other members of the Flaviviridae family, the 3' non-translated region (NTR) of the hepatitis C virus (HCV) is believed to function in the initiation and regulation of viral RNA replication by interacting with components of the viral replicase complex. To inves-tigate the possibility that host components may also participate in this process, we used UV cross-linking assays to determine if any cellular proteins could bind specifically to the 3'NTR RNA. We demonstrate the specific interaction of two host proteins with the extensive pyrimidine-rich region within the HCV 3'NTR. One host protein migrates as a doublet with a molecular weight of 57 kDa and is immunoreactive with antisera specific for polypyrimidine tract-binding protein (PTB), and the other protein (35 kDa) is recognized by a monoclonal antibody specific for heterogeneous nuclear ribonucleoprotein C (hnRNP C). These results suggest that recognition of the large pyrimidine-rich region by PTB and hnRNP C may play a role in the initiation and/or regulation of HCV RNA replication.  (+info)

Identification of the poly(C) binding protein in the complex associated with the 3' untranslated region of erythropoietin messenger RNA. (4/856)

Hypoxia regulates expression of erythropoietin (EPO), a glycoprotein that stimulates erythrocytosis, at the level of transcription and also possibly at the level of messenger RNA (mRNA) stability. A pyrimidine-rich region within the EPO mRNA 3' untranslated region was implicated in regulation of EPO mRNA stability element and shown to bind protein factors. In the present study we wished to identify the protein factor binding to the pyrimidine-rich sequence in the EPO mRNA stability element. Using mobility shift assays, ultraviolet light cross-linking, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and electroelution of protein factors from the gel slices corresponding to the ribonucleoprotein complexes, we found that two isoforms of a 40 kD poly(C) binding protein (PCBP, also known as alphaCP or hnRNPE), PCBP1, and PCBP2 are present in that complex. In Hep3B or HepG2 cells hypoxia induces neither expression of PCBP nor formation of the ribonucleoprotein complex associated with EPO mRNA that involves PCBP.  (+info)

Binding of hnRNP H to an exonic splicing silencer is involved in the regulation of alternative splicing of the rat beta-tropomyosin gene. (5/856)

In the rat beta-tropomyosin (beta-TM) gene, exons 6 and 7 are spliced alternatively in a mutually exclusive manner. Exon 6 is included in mRNA encoding nonmuscle TM-1, whereas exon 7 is used in mRNA encoding skeletal muscle beta-TM. Previously, we demonstrated that a six nucleotide mutation at the 5' end of exon 7, designated as ex-1, activated exon 7 splicing in nonmuscle cells. In this study, we show that the activating effect of this mutation is not the result of creating an exonic splicing enhancer (ESE) or disrupting a putative secondary structure. The sequence in exon 7 acts as a bona fide exonic splicing silencer (ESS), which is bound specifically by a trans-acting factor. Isolation and peptide sequencing reveal that this factor is hnRNP H, a member of the heterogeneous nuclear ribonucleoprotein (hnRNP) family. Binding of hnRNP H correlates with the ESS activity. Furthermore, addition of antibodies that specifically recognizes hnRNP H to the splicing reactions or partial depletion of hnRNP H from nuclear extract activates exon 7 splicing in vitro and this effect can be reversed by addition of purified recombinant hnRNP H. These results indicate that hnRNP H participates in exclusion of exon 7 in nonmuscle cells. The involvement of hnRNP H in the activity of an ESS may represent a prototype for the regulation of tissue- and developmental-specific alternative splicing.  (+info)

Polypyrimidine-tract binding protein (PTB) is necessary, but not sufficient, for efficient internal initiation of translation of human rhinovirus-2 RNA. (6/856)

Initiation of translation of the animal picornavirus RNAs is via a mechanism of direct internal ribosome entry, which requires a substantial segment of the viral 5'-untranslated region, generally known as the IRES (for "internal ribosome entry site"). Because, however, translation of the RNAs of members of the enterovirus, and more especially, the rhinovirus subgroups of the Picornaviridae is restricted in the reticulocyte lysate system, but is greatly stimulated by the addition of HeLa cell extracts, the implication is that, in these cases, internal initiation also requires cellular trans-acting factors that are more abundant in HeLa cell extracts than in rabbit reticulocytes. This was used as the basis of a functional assay for the purification of the HeLa cell factors required for translation dependent on the human rhinovirus-2 (HRV) IRES. There are two such HeLa cell factors separable by ion-exchange chromatography, each of which is individually active in the assay, although their combined effect is synergistic. One of these activities is shown to be polypyrimidine-tract binding protein (PTB) on the grounds that (1) the activity copurifies to homogeneity with PTB and (2) recombinant PTB expressed in Escherichia coli stimulates HRV IRES-dependent translation with a specific activity similar to that of the purified HeLa cell factor. Furthermore, it is shown that recombinant PTB also stimulates the translation of RNAs bearing the poliovirus type 1 (Mahoney) IRES.  (+info)

Identification of chURP, a nuclear calmodulin-binding protein related to hnRNP-U. (7/856)

In a screen for myosin-like proteins in embryonic chicken brain, we have identified a novel nuclear protein structurally related to hnRNP-U (heterogeneous nuclear ribonuclear protein U). We have called this protein chURP, for chicken U-related protein. In this screen, chURP was immunoreactive with two myosin antibodies and, in common with the unconventional myosins, bound calmodulin in vitro in both the presence and absence of calcium ions. Determination of 757 amino acids of the chURP sequence revealed that it shares 41% amino acid identity with human and rat hnRNP-U, although chURP and hnRNP-U appear not to be orthologous proteins. ChURP is ubiquitously expressed in the nuclei of all chick tissues and, as one of a growing number of calmodulin-binding proteins to be identified in the nucleus, further highlights the potential of calmodulin as a regulator of nuclear metabolism.  (+info)

Heterogeneous nuclear ribonucleoprotein B1 as a new marker of early detection for human lung cancers. (8/856)

Heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 is an RNA binding protein that is required for maturation of mRNA precursor. Tockman et al. previously reported that hnRNP A2/B1 with a M(r) of 31,000 is overexpressed from the early clinical stage of human lung cancer (M. S. Tockman et al., J. Clin. Oncol., 6: 1685-1693, 1988). However, when hnRNP A2/B1 mRNA and hnRNP B1 mRNA were separately studied, we found unique evidence that hnRNP B1 mRNA, which is a splicing variant of hnRNP A2 mRNA, was more significantly elevated in lung cancer tissues than hnRNP A2/B1 mRNA. Our hnRNP B1-specific polyclonal antibody specifically recognized hnRNP B1 protein as a M(r) 37,000 nuclear protein by Western blotting but did not recognize hnRNP A2 protein. Immunohistochemical staining with the hnRNP B1 antibody revealed that hnRNP B1 protein was specifically stained in the nuclei of human cancer cells, and in squamous cell carcinomas in particular, but not in those of normal adjacent lung epithelial cells. We think that hnRNP B1 protein of M(r) 37,000, not hnRNP A2, is well qualified as a biomarker for the detection of human lung cancer.  (+info)

Heterogeneous Nuclear Ribonucleoproteins (hnRNPs) are a type of nuclear protein complex associated with nascent RNA transcripts in the nucleus of eukaryotic cells. They play crucial roles in various aspects of RNA metabolism, including processing, transport, stability, and translation.

The term "heterogeneous" refers to the diverse range of proteins that make up these complexes, while "nuclear" indicates their location within the nucleus. The hnRNPs are composed of a core protein component and associated RNA molecules, primarily heterogeneous nuclear RNAs (hnRNAs) or pre-messenger RNAs (pre-mRNAs).

There are over 20 different hnRNP proteins identified so far, each with distinct functions and structures. Some of the well-known hnRNPs include hnRNP A1, hnRNP C, and hnRNP U. These proteins contain several domains that facilitate RNA binding, protein-protein interactions, and post-translational modifications.

The primary function of hnRNPs is to regulate gene expression at the post-transcriptional level by interacting with RNA molecules. They participate in splicing, 3' end processing, export, localization, stability, and translation of mRNAs. Dysregulation of hnRNP function has been implicated in various human diseases, including neurological disorders and cancer.

Heterogeneous Nuclear RNA (hnRNA) is a type of RNA molecule found in the nucleus of eukaryotic cells during the early stages of gene expression. The term "heterogeneous" refers to the diverse range of sizes and structures that these RNAs exhibit, which can vary from several hundred to tens of thousands of nucleotides in length.

HnRNA is transcribed from DNA templates by the enzyme RNA polymerase II and includes both introns (non-coding sequences) and exons (coding sequences) that will eventually be spliced together to form mature mRNA molecules. HnRNA also contains additional sequences, such as 5' cap structures and 3' poly(A) tails, which are added during post-transcriptional processing.

Because hnRNA is a precursor to mature mRNA, it is often used as a marker for transcriptionally active genes. However, not all hnRNA molecules are ultimately processed into mRNA; some may be degraded or converted into other types of RNA, such as microRNAs or long non-coding RNAs.

Overall, hnRNA plays a critical role in the regulation and expression of genes in eukaryotic cells.

Ribonucleoproteins (RNPs) are complexes composed of ribonucleic acid (RNA) and proteins. They play crucial roles in various cellular processes, including gene expression, RNA processing, transport, stability, and degradation. Different types of RNPs exist, such as ribosomes, spliceosomes, and signal recognition particles, each having specific functions in the cell.

Ribosomes are large RNP complexes responsible for protein synthesis, where messenger RNA (mRNA) is translated into proteins. They consist of two subunits: a smaller subunit containing ribosomal RNA (rRNA) and proteins that recognize the start codon on mRNA, and a larger subunit with rRNA and proteins that facilitate peptide bond formation during translation.

Spliceosomes are dynamic RNP complexes involved in pre-messenger RNA (pre-mRNA) splicing, where introns (non-coding sequences) are removed, and exons (coding sequences) are joined together to form mature mRNA. Spliceosomes consist of five small nuclear ribonucleoproteins (snRNPs), each containing a specific small nuclear RNA (snRNA) and several proteins, as well as numerous additional proteins.

Other RNP complexes include signal recognition particles (SRPs), which are responsible for targeting secretory and membrane proteins to the endoplasmic reticulum during translation, and telomerase, an enzyme that maintains the length of telomeres (the protective ends of chromosomes) by adding repetitive DNA sequences using its built-in RNA component.

In summary, ribonucleoproteins are essential complexes in the cell that participate in various aspects of RNA metabolism and protein synthesis.

Heterogeneous Nuclear Ribonucleoproteins (hnRNPs) are a group of nuclear proteins that are involved in the processing and metabolism of messenger RNA (mRNA). They were named "heterogeneous" because they were initially found to be associated with a heterogeneous population of RNA molecules. The hnRNPs are divided into several subfamilies, A and B being two of them.

The hnRNP A-B group is composed of proteins that share structural similarities and have overlapping functions in the regulation of mRNA metabolism. These proteins play a role in various aspects of RNA processing, including splicing, 3' end processing, transport, stability, and translation.

The hnRNP A-B group includes several members, such as hnRNPA1, hnRNPA2/B1, and hnRNPC. These proteins contain RNA recognition motifs (RRMs) that allow them to bind to specific sequences in the RNA molecules. They can also interact with other proteins and form complexes that regulate mRNA function.

Mutations in genes encoding hnRNP A-B group members have been associated with several human diseases, including neurodegenerative disorders, myopathies, and cancer. Therefore, understanding the structure and function of these proteins is essential for elucidating their role in disease pathogenesis and developing potential therapeutic strategies.

Heterogeneous Nuclear Ribonucleoproteins (hnRNPs) are a group of nuclear proteins that are involved in the processing and metabolism of messenger RNA (mRNA). The hnRNPs are divided into several subgroups, A to U.

The F/H subgroup includes two closely related proteins, hnRNP F and hnRNP H, which share a high degree of sequence similarity. These proteins are involved in various aspects of mRNA metabolism, including splicing, 3'-end processing, transport, stability, and translation.

Specifically, hnRNP F has been shown to play a role in the regulation of alternative splicing by binding to specific RNA sequences and modulating splice site selection. It also interacts with other proteins involved in splicing and mRNA transport.

Similarly, hnRNP H is involved in various aspects of mRNA metabolism, including splicing, 3'-end processing, and translation. It has been shown to bind to specific RNA sequences and regulate alternative splicing by promoting or repressing the inclusion of certain exons.

Together, hnRNP F and hnRNP H form heterodimers that can interact with other proteins and RNAs to regulate gene expression in a coordinated manner. Mutations in these proteins have been associated with various human diseases, including cancer and neurological disorders.

Small nuclear ribonucleoproteins (snRNPs) are a type of ribonucleoprotein (RNP) found within the nucleus of eukaryotic cells. They are composed of small nuclear RNA (snRNA) molecules and associated proteins, which are involved in various aspects of RNA processing, particularly in the modification and splicing of messenger RNA (mRNA).

The snRNPs play a crucial role in the formation of spliceosomes, large ribonucleoprotein complexes that remove introns (non-coding sequences) from pre-mRNA and join exons (coding sequences) together to form mature mRNA. Each snRNP contains a specific snRNA molecule, such as U1, U2, U4, U5, or U6, which recognizes and binds to specific sequences within the pre-mRNA during splicing. The associated proteins help stabilize the snRNP structure and facilitate its interactions with other components of the spliceosome.

In addition to their role in splicing, some snRNPs are also involved in other cellular processes, such as transcription regulation, RNA export, and DNA damage response. Dysregulation or mutations in snRNP components have been implicated in various human diseases, including cancer, neurological disorders, and autoimmune diseases.

Heterogeneous Nuclear Ribonucleoproteins (hnRNPs) are a group of nuclear proteins that are involved in the processing and metabolism of RNA. The 'Group C' hnRNPs refer to a specific subclass of these proteins, which include hnRNP C1 and hnRNP C2. These proteins are highly similar in their amino acid sequences and have molecular weights of approximately 34-36 kDa. They play important roles in various aspects of RNA metabolism, including pre-mRNA splicing, mRNA stability, and translation. Mutations in hnRNP C proteins have been associated with certain neurological disorders, such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD).

RNA-binding proteins (RBPs) are a class of proteins that selectively interact with RNA molecules to form ribonucleoprotein complexes. These proteins play crucial roles in the post-transcriptional regulation of gene expression, including pre-mRNA processing, mRNA stability, transport, localization, and translation. RBPs recognize specific RNA sequences or structures through their modular RNA-binding domains, which can be highly degenerate and allow for the recognition of a wide range of RNA targets. The interaction between RBPs and RNA is often dynamic and can be regulated by various post-translational modifications of the proteins or by environmental stimuli, allowing for fine-tuning of gene expression in response to changing cellular needs. Dysregulation of RBP function has been implicated in various human diseases, including neurological disorders and cancer.

Heterogeneous Nuclear Ribonucleoprotein K (hnRNP K) is a member of the family of heterogeneous nuclear ribonucleoproteins (hnRNPs), which are proteins that bind to RNA molecules in the nucleus of eukaryotic cells. These proteins play important roles in various aspects of RNA metabolism, including processing, transport, and stability.

Specifically, hnRNP K is a multifunctional protein that has been shown to participate in several cellular processes, such as transcription, splicing, mRNA stabilization, and translation. It can bind to both DNA and RNA molecules, and its binding affinity is influenced by various post-translational modifications, including phosphorylation, methylation, and acetylation.

hnRNP K has been implicated in the development and progression of several human diseases, including cancer, neurodegenerative disorders, and viral infections. Its expression levels and subcellular localization are often altered in these conditions, making it a potential target for therapeutic intervention.

RNA splicing is a post-transcriptional modification process in which the non-coding sequences (introns) are removed and the coding sequences (exons) are joined together in a messenger RNA (mRNA) molecule. This results in a continuous mRNA sequence that can be translated into a single protein. Alternative splicing, where different combinations of exons are included or excluded, allows for the creation of multiple proteins from a single gene.

RNA precursors, also known as primary transcripts or pre-messenger RNAs (pre-mRNAs), refer to the initial RNA molecules that are synthesized during the transcription process in which DNA is copied into RNA. These precursor molecules still contain non-coding sequences and introns, which need to be removed through a process called splicing, before they can become mature and functional RNAs such as messenger RNAs (mRNAs), ribosomal RNAs (rRNAs), or transfer RNAs (tRNAs).

Pre-mRNAs undergo several processing steps, including 5' capping, 3' polyadenylation, and splicing, to generate mature mRNA molecules that can be translated into proteins. The accurate and efficient production of RNA precursors and their subsequent processing are crucial for gene expression and regulation in cells.

Nucleocytoplasmic transport proteins are a group of specialized proteins that facilitate the exchange of molecules between the nucleus and the cytoplasm of a eukaryotic cell. These proteins are essential for regulating various cellular processes, including gene expression, signal transduction, and protein synthesis.

The nuclear envelope, which surrounds the nucleus, contains pores called nuclear pore complexes (NPCs) that act as gatekeepers, controlling the movement of molecules in and out of the nucleus. Nucleocytoplasmic transport proteins interact with these NPCs to mediate the translocation of macromolecules such as RNA, DNA, and proteins through the nuclear pore.

There are two main types of nucleocytoplasmic transport proteins: importins and exportins. Importins recognize and bind to specific nuclear localization signals (NLS) present on cargo molecules destined for the nucleus, while exportins interact with nuclear export signals (NES) found on cargoes that need to be transported out of the nucleus.

Once bound to their respective cargoes, these transport proteins form a complex and utilize energy from GTP hydrolysis to move through the NPC and release the cargo into the target compartment (nucleus or cytoplasm). The regulation of this process is crucial for maintaining proper cellular function and homeostasis. Dysfunction in nucleocytoplasmic transport proteins has been implicated in several diseases, including neurodegenerative disorders and cancers.

HeLa cells are a type of immortalized cell line used in scientific research. They are derived from a cancer that developed in the cervical tissue of Henrietta Lacks, an African-American woman, in 1951. After her death, cells taken from her tumor were found to be capable of continuous division and growth in a laboratory setting, making them an invaluable resource for medical research.

HeLa cells have been used in a wide range of scientific studies, including research on cancer, viruses, genetics, and drug development. They were the first human cell line to be successfully cloned and are able to grow rapidly in culture, doubling their population every 20-24 hours. This has made them an essential tool for many areas of biomedical research.

It is important to note that while HeLa cells have been instrumental in numerous scientific breakthroughs, the story of their origin raises ethical questions about informed consent and the use of human tissue in research.

The cell nucleus is a membrane-bound organelle found in the eukaryotic cells (cells with a true nucleus). It contains most of the cell's genetic material, organized as DNA molecules in complex with proteins, RNA molecules, and histones to form chromosomes.

The primary function of the cell nucleus is to regulate and control the activities of the cell, including growth, metabolism, protein synthesis, and reproduction. It also plays a crucial role in the process of mitosis (cell division) by separating and protecting the genetic material during this process. The nuclear membrane, or nuclear envelope, surrounding the nucleus is composed of two lipid bilayers with numerous pores that allow for the selective transport of molecules between the nucleoplasm (nucleus interior) and the cytoplasm (cell exterior).

The cell nucleus is a vital structure in eukaryotic cells, and its dysfunction can lead to various diseases, including cancer and genetic disorders.

SnRNP (small nuclear ribonucleoprotein) core proteins are a group of proteins that are associated with small nuclear RNAs (snRNAs) to form small nuclear ribonucleoprotein particles. These particles play crucial roles in various aspects of RNA processing, such as splicing, 3' end formation, and degradation.

The snRNP core proteins include seven Sm proteins (B, D1, D2, D3, E, F, and G) that form a heptameric ring-like structure called the Sm core, which binds to a conserved sequence motif in the snRNAs called the Sm site. In addition to the Sm proteins, there are also other core proteins such as Sm like (L) proteins and various other protein factors that associate with specific snRNP particles.

Together, these snRNP core proteins help to stabilize the snRNA, facilitate its assembly into functional ribonucleoprotein complexes, and participate in the recognition and processing of target RNAs during post-transcriptional regulation.

Coiled bodies are nuclear structures found in the cells of higher organisms. They are composed of masses of DNA and RNA, as well as proteins. Coiled bodies are also known as Cajal bodies, after the Spanish histologist and neuroscientist Santiago Ramón y Cajal who first described them.

Coiled bodies are involved in various aspects of nuclear function, including the modification and processing of ribonucleoprotein (RNP) complexes, which are important for the regulation of gene expression. They also play a role in the biogenesis of telomerase, an enzyme that is responsible for maintaining the length and integrity of telomeres, the protective caps on the ends of chromosomes.

Coiled bodies are often associated with active genes and are thought to be involved in the regulation of gene expression. They have been implicated in a number of cellular processes, including transcription, splicing, and the transport of RNA. Coiled bodies are dynamic structures that can change in size and number in response to various stimuli, such as changes in the cell cycle or exposure to certain drugs.

It is worth noting that while coiled bodies have been well-studied, there is still much that is not known about their precise functions and how they contribute to normal cellular processes and disease.

A spliceosome is a complex of ribonucleoprotein (RNP) particles found in the nucleus of eukaryotic cells that removes introns (non-coding sequences) from precursor messenger RNA (pre-mRNA) and joins exons (coding sequences) together to form mature mRNA. This process is called splicing, which is an essential step in gene expression and protein synthesis. Spliceosomes are composed of five small nuclear ribonucleoprotein particles (snRNPs), known as U1, U2, U4/U6, and U5 snRNPs, and numerous proteins. The assembly of spliceosomes and the splicing reaction are highly regulated and can be influenced by various factors, including cis-acting elements in pre-mRNA and trans-acting factors such as serine/arginine-rich (SR) proteins.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Small nuclear RNA (snRNA) are a type of RNA molecules that are typically around 100-300 nucleotides in length. They are found within the nucleus of eukaryotic cells and are components of small nuclear ribonucleoproteins (snRNPs), which play important roles in various aspects of RNA processing, including splicing of pre-messenger RNA (pre-mRNA) and regulation of transcription.

There are several classes of snRNAs, each with a distinct function. The most well-studied class is the spliceosomal snRNAs, which include U1, U2, U4, U5, and U6 snRNAs. These snRNAs form complexes with proteins to form small nuclear ribonucleoprotein particles (snRNPs) that recognize specific sequences in pre-mRNA and catalyze the removal of introns during splicing.

Other classes of snRNAs include signal recognition particle (SRP) RNA, which is involved in targeting proteins to the endoplasmic reticulum, and Ro60 RNA, which is associated with autoimmune diseases such as systemic lupus erythematosus.

Overall, small nuclear RNAs are essential components of the cellular machinery that regulates gene expression and protein synthesis in eukaryotic cells.

The Survival Motor Neuron (SMN) complex is a protein complex that plays a crucial role in the biogenesis of small nuclear ribonucleoproteins (snRNPs), which are essential components of the spliceosome involved in pre-messenger RNA (pre-mRNA) splicing. The SMN complex consists of several proteins, including the SMN protein itself, Gemins2-8, and unrip.

The SMN protein is the central component of the complex and is encoded by the SMN1 gene located on chromosome 5q13.2. Mutations in this gene can lead to spinal muscular atrophy (SMA), a genetic disorder characterized by degeneration of motor neurons in the spinal cord, leading to muscle weakness and atrophy.

The SMN complex assembles in the cytoplasm and facilitates the assembly of spliceosomal snRNPs by helping to load Sm proteins onto small nuclear RNA (snRNA) molecules. Proper functioning of the SMN complex is essential for the correct splicing of pre-mRNA, and its dysfunction can lead to various developmental abnormalities and diseases, including SMA.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

A ribonucleoprotein, U4-U6 small nuclear (snRNP) is a type of small nuclear ribonucleoprotein particle that plays a crucial role in the splicing of pre-messenger RNA (pre-mRNA) in the nucleus of eukaryotic cells. Specifically, U4-U6 snRNP is part of the spliceosome complex, which catalyzes the removal of introns (non-coding sequences) from pre-mRNA during the process of gene expression.

The U4-U6 snRNP is composed of several proteins and three small nuclear RNAs (snRNAs): U4, U6, and U6atac. These snRNAs are highly conserved across different species and are essential for the stability and function of the U4-U6 snRNP complex. The U4 and U6 snRNAs form a specific base-pairing interaction that is critical for the assembly and activity of the spliceosome.

During splicing, the U4-U6 snRNP interacts with other snRNPs (U1, U2, and U5) to form a large ribonucleoprotein complex called the spliceosome. The U4-U6 snRNP then undergoes a series of conformational changes that ultimately lead to the formation of the active site for splicing. This process involves the displacement of U4 snRNA from U6 snRNA, allowing U6 snRNA to base-pair with the intron and form the catalytic core of the spliceosome.

Defects in U4-U6 snRNP biogenesis or function have been implicated in various human diseases, including cancer, neurological disorders, and autoimmune diseases.

Nuclear proteins are a category of proteins that are primarily found in the nucleus of a eukaryotic cell. They play crucial roles in various nuclear functions, such as DNA replication, transcription, repair, and RNA processing. This group includes structural proteins like lamins, which form the nuclear lamina, and regulatory proteins, such as histones and transcription factors, that are involved in gene expression. Nuclear localization signals (NLS) often help target these proteins to the nucleus by interacting with importin proteins during active transport across the nuclear membrane.

DEAD-Box Protein 20 (DDX20) is a member of the DEAD-box protein family, which are named for the conserved amino acid sequence "Asp-Glu-Ala-Asp" within their helicase domains. These proteins are involved in various aspects of RNA metabolism, including splicing, transport, translation, and degradation.

DDX20, also known as p68 or DP103, is a DNA/RNA helicase that plays a role in transcriptional regulation, pre-mRNA processing, and RNA export. It has been implicated in several cellular processes, including cell cycle progression, differentiation, and apoptosis. DDX20 can interact with various proteins involved in transcription, such as RNA polymerase II and the basal transcription factor TFIID, as well as components of the spliceosome and other RNA-binding proteins.

Mutations or dysregulation of DDX20 have been associated with several human diseases, including cancer, neurodevelopmental disorders, and autoimmune diseases. For example, increased expression of DDX20 has been observed in various types of cancer, such as breast, lung, and ovarian cancers, and may contribute to tumor progression by promoting cell proliferation and inhibiting apoptosis. Additionally, mutations in the gene encoding DDX20 have been identified in patients with intellectual disability, epilepsy, and autism spectrum disorder.

Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.

Two-dimensional (2D) gel electrophoresis is a type of electrophoretic technique used in the separation and analysis of complex protein mixtures. This method combines two types of electrophoresis – isoelectric focusing (IEF) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) – to separate proteins based on their unique physical and chemical properties in two dimensions.

In the first dimension, IEF separates proteins according to their isoelectric points (pI), which is the pH at which a protein carries no net electrical charge. The proteins are focused into narrow zones along a pH gradient established within a gel strip. In the second dimension, SDS-PAGE separates the proteins based on their molecular weights by applying an electric field perpendicular to the first dimension.

The separated proteins form distinct spots on the 2D gel, which can be visualized using various staining techniques. The resulting protein pattern provides valuable information about the composition and modifications of the protein mixture, enabling researchers to identify and compare different proteins in various samples. Two-dimensional gel electrophoresis is widely used in proteomics research, biomarker discovery, and quality control in protein production.

A ribonucleoprotein, U1 small nuclear (U1 snRNP) is a type of small nuclear ribonucleoprotein (snRNP) particle that is found within the nucleus of eukaryotic cells. These complexes are essential for various aspects of RNA processing, particularly in the form of spliceosomes, which are responsible for removing introns from pre-messenger RNA (pre-mRNA) during the process of gene expression.

The U1 snRNP is composed of a small nuclear RNA (snRNA) molecule called U1 snRNA, several proteins, and occasionally other non-coding RNAs. The U1 snRNA contains conserved sequences that recognize and bind to specific sequences in the pre-mRNA, forming base pairs with complementary regions within the intron. This interaction is crucial for the accurate identification and removal of introns during splicing.

In addition to its role in splicing, U1 snRNP has been implicated in other cellular processes such as transcription regulation, RNA decay, and DNA damage response. Dysregulation or mutations in U1 snRNP components have been associated with various human diseases, including cancer and neurological disorders.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

A ribonucleoprotein, U5 small nuclear (snRNP), is a type of spliceosomal small nuclear ribonucleoprotein (snRNP) particle that plays a crucial role in the process of pre-messenger RNA (pre-mRNA) splicing. Pre-mRNA splicing is the removal of non-coding sequences, called introns, from the pre-mRNA molecule and the joining together of the remaining coding sequences, or exons, to form a mature mRNA molecule that can be translated into protein.

The U5 snRNP particle consists of a small uridine-rich RNA (U5 snRNA) molecule and several associated proteins. The U5 snRNA contains highly conserved sequences that are important for its recognition by the other components of the spliceosome, which is the large ribonucleoprotein complex responsible for pre-mRNA splicing.

During the splicing process, the U5 snRNP particle interacts with other snRNP particles (U1, U2, and U4/U6) to form a functional spliceosome that catalyzes the splicing reaction. The U5 snRNA base-pairs with the intron sequences at the 5' and 3' splice sites, helping to position the exons for splicing. After the splicing reaction is complete, the U5 snRNP particle is released from the spliceosome and can be recycled for further rounds of splicing.

Defects in the components of the U5 snRNP particle have been implicated in several human diseases, including certain forms of cancer and neurological disorders.

"Notophthalmus viridescens" is the scientific name for a species of salamander, commonly known as the Eastern Newt or the Red-spotted Newt. It is not a medical term. The Eastern Newt is found in the eastern parts of North America and undergoes three distinct life stages: aquatic larva, terrestrial juvenile (known as an "ef," short for "effluent"), and fully aquatic adult. They are known for their distinctive coloration and toxic skin secretions, which serve as a defense against predators.

A ribonucleoprotein, U2 small nuclear (U2 snRNP) is a type of spliceosomal small nuclear ribonucleoprotein (snRNP) complex that plays a crucial role in the pre-messenger RNA (pre-mRNA) splicing process during gene expression in eukaryotic cells.

Pre-mRNA splicing is the removal of non-coding sequences, called introns, from the pre-mRNA molecule and the joining together of the remaining coding sequences, or exons, to form a continuous mRNA sequence that can be translated into protein. U2 snRNPs are essential components of the spliceosome, the large ribonucleoprotein complex responsible for pre-mRNA splicing.

The U2 snRNP is composed of several proteins and a small nuclear RNA (snRNA) molecule called U2 small nuclear RNA (U2 snRNA). The U2 snRNA binds to specific sequences within the pre-mRNA, forming part of the intron's branch site, which helps define the boundaries of the exons and introns. This interaction facilitates the recognition and assembly of other spliceosomal components, ultimately leading to the precise excision of introns and ligation of exons in the mature mRNA molecule.

In summary, U2 snRNP is a ribonucleoprotein complex involved in pre-mRNA splicing, where it plays a critical role in recognizing and processing intron-exon boundaries during gene expression in eukaryotic cells.

Nucleoproteins are complexes formed by the association of proteins with nucleic acids (DNA or RNA). These complexes play crucial roles in various biological processes, such as packaging and protecting genetic material, regulating gene expression, and replication and repair of DNA. In these complexes, proteins interact with nucleic acids through electrostatic, hydrogen bonding, and other non-covalent interactions, leading to the formation of stable structures that help maintain the integrity and function of the genetic material. Some well-known examples of nucleoproteins include histones, which are involved in DNA packaging in eukaryotic cells, and reverse transcriptase, an enzyme found in retroviruses that transcribes RNA into DNA.

Autoantigens are substances that are typically found in an individual's own body, but can stimulate an immune response because they are recognized as foreign by the body's own immune system. In autoimmune diseases, the immune system mistakenly attacks and damages healthy tissues and organs because it recognizes some of their components as autoantigens. These autoantigens can be proteins, DNA, or other molecules that are normally present in the body but have become altered or exposed due to various factors such as infection, genetics, or environmental triggers. The immune system then produces antibodies and activates immune cells to attack these autoantigens, leading to tissue damage and inflammation.

Protein-Arginine N-Methyltransferases (PRMTs) are a group of enzymes that catalyze the transfer of methyl groups from S-adenosylmethionine to specific arginine residues in proteins, leading to the formation of N-methylarginines. This post-translational modification plays a crucial role in various cellular processes such as signal transduction, DNA repair, and RNA processing. There are nine known PRMTs in humans, which can be classified into three types based on the type of methylarginine produced: Type I (PRMT1, 2, 3, 4, 6, and 8) produce asymmetric dimethylarginines, Type II (PRMT5 and 9) produce symmetric dimethylarginines, and Type III (PRMT7) produces monomethylarginine. Aberrant PRMT activity has been implicated in several diseases, including cancer and neurological disorders.

Spinal muscular atrophy (SMA) is a genetic disorder that affects the motor neurons in the spinal cord, leading to muscle weakness and atrophy. It is caused by a mutation in the survival motor neuron 1 (SMN1) gene, which results in a deficiency of SMN protein necessary for the survival of motor neurons.

There are several types of SMA, classified based on the age of onset and severity of symptoms. The most common type is type 1, also known as Werdnig-Hoffmann disease, which presents in infancy and is characterized by severe muscle weakness, hypotonia, and feeding difficulties. Other types include type 2 (intermediate SMA), type 3 (Kugelberg-Welander disease), and type 4 (adult-onset SMA).

The symptoms of SMA may include muscle wasting, fasciculations, weakness, hypotonia, respiratory difficulties, and mobility impairment. The diagnosis of SMA typically involves genetic testing to confirm the presence of a mutation in the SMN1 gene. Treatment options for SMA may include medications, physical therapy, assistive devices, and respiratory support.

"Small cytoplasmic RNAs" (scRNAs) are a heterogeneous group of non-coding RNA molecules that are typically 100-300 nucleotides in length and are located within the cytoplasm of cells. They play various roles in post-transcriptional regulation of gene expression, including serving as components of ribonucleoprotein complexes involved in mRNA splicing, stability, and translation.

Some specific types of scRNAs include small nuclear RNAs (snRNAs), which are involved in spliceosomal complexes that remove introns from pre-mRNA; small nucleolar RNAs (snoRNAs), which guide chemical modifications of other RNA molecules, such as ribosomal RNAs (rRNAs); and microRNAs (miRNAs), which bind to target mRNAs and inhibit their translation or promote their degradation.

It's worth noting that the term "small cytoplasmic RNA" is a broad category, and individual scRNAs can have distinct functions and characteristics.

RNA (Ribonucleic Acid) is a single-stranded, linear polymer of ribonucleotides. It is a nucleic acid present in the cells of all living organisms and some viruses. RNAs play crucial roles in various biological processes such as protein synthesis, gene regulation, and cellular signaling. There are several types of RNA including messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA), small nuclear RNA (snRNA), microRNA (miRNA), and long non-coding RNA (lncRNA). These RNAs differ in their structure, function, and location within the cell.

Survival of Motor Neuron 1 (SMN1) protein is a critical component for the survival of motor neurons, which are nerve cells that control muscle movements. The SMN1 protein is produced by the Survival of Motor Neuron 1 gene, located on human chromosome 5q13.

The primary function of the SMN1 protein is to assist in the biogenesis of small nuclear ribonucleoproteins (snRNPs), which are essential for spliceosomes - complex molecular machines responsible for RNA processing in the cell. The absence or significant reduction of SMN1 protein leads to defective snRNP assembly, impaired RNA splicing, and ultimately results in motor neuron degeneration.

Mutations in the SMN1 gene can cause Spinal Muscular Atrophy (SMA), a genetic disorder characterized by progressive muscle weakness, atrophy, and paralysis due to the loss of lower motor neurons in the spinal cord. The severity of SMA depends on the amount of functional SMN1 protein produced, with less protein leading to more severe symptoms.

Post-transcriptional RNA processing refers to the modifications and regulations that occur on RNA molecules after the transcription of DNA into RNA. This process includes several steps:

1. 5' capping: The addition of a cap structure, usually a methylated guanosine triphosphate (GTP), to the 5' end of the RNA molecule. This helps protect the RNA from degradation and plays a role in its transport, stability, and translation.
2. 3' polyadenylation: The addition of a string of adenosine residues (poly(A) tail) to the 3' end of the RNA molecule. This process is important for mRNA stability, export from the nucleus, and translation initiation.
3. Intron removal and exon ligation: Eukaryotic pre-messenger RNAs (pre-mRNAs) contain intronic sequences that do not code for proteins. These introns are removed by a process called splicing, where the flanking exons are joined together to form a continuous mRNA sequence. Alternative splicing can lead to different mature mRNAs from a single pre-mRNA, increasing transcriptomic and proteomic diversity.
4. RNA editing: Specific nucleotide changes in RNA molecules that alter the coding potential or regulatory functions of RNA. This process is catalyzed by enzymes like ADAR (Adenosine Deaminases Acting on RNA) and APOBEC (Apolipoprotein B mRNA Editing Catalytic Polypeptide-like).
5. Chemical modifications: Various chemical modifications can occur on RNA nucleotides, such as methylation, pseudouridination, and isomerization. These modifications can influence RNA stability, localization, and interaction with proteins or other RNAs.
6. Transport and localization: Mature mRNAs are transported from the nucleus to the cytoplasm for translation. In some cases, specific mRNAs are localized to particular cellular compartments to ensure local protein synthesis.
7. Degradation: RNA molecules have finite lifetimes and undergo degradation by various ribonucleases (RNases). The rate of degradation can be influenced by factors such as RNA structure, modifications, or interactions with proteins.

Nucleic acid precursors are the molecules that are used in the synthesis of nucleotides, which are the building blocks of nucleic acids, including DNA and RNA. The two main types of nucleic acid precursors are nucleoside triphosphates (deoxyribonucleoside triphosphates for DNA and ribonucleoside triphosphates for RNA) and their corresponding pentose sugars (deoxyribose for DNA and ribose for RNA).

Nucleoside triphosphates consist of a nitrogenous base, a pentose sugar, and three phosphate groups. The nitrogenous bases in nucleic acids are classified as purines (adenine and guanine) or pyrimidines (thymine, cytosine, and uracil). In the synthesis of nucleotides, nucleophilic attack by the nitrogenous base on a pentose sugar in the form of a phosphate ester leads to the formation of a glycosidic bond between the base and the sugar. The addition of two more phosphate groups through anhydride linkages forms the nucleoside triphosphate.

The synthesis of nucleic acids involves the sequential addition of nucleotides to a growing chain, with the removal of a pyrophosphate group from each nucleotide providing energy for the reaction. The process is catalyzed by enzymes called polymerases, which use nucleic acid templates to ensure the correct base-pairing and sequence of nucleotides in the final product.

In summary, nucleic acid precursors are the molecules that provide the building blocks for the synthesis of DNA and RNA, and include nucleoside triphosphates and their corresponding pentose sugars.

Small nucleolar ribonucleoproteins (snoRNPs) are a type of ribonucleoprotein complex found in the nucleus of eukaryotic cells. They play a crucial role in the post-transcriptional modification of ribosomal RNA (rRNA) and small nuclear RNA (snRNA). Specifically, snoRNPs are responsible for guiding the addition of methyl groups to specific nucleotides in rRNA and snRNA, a process known as 2'-O-methylation.

Small nucleolar ribonucleoproteins are composed of two main components: a small nucleolar RNA (snoRNA) and several proteins. The snoRNA molecule contains a conserved sequence that base-pairs with the target rRNA or snRNA, forming a structure that positions the methyl group donor enzyme, methyltransferase, in close proximity to the nucleotide to be modified.

Small nucleolar ribonucleoproteins are classified into two main categories based on their snoRNA components: box C/D snoRNPs and box H/ACA snoRNPs. Box C/D snoRNPs guide 2'-O-methylation, while box H/ACA snoRNPs are responsible for pseudouridination, another type of RNA modification.

Overall, small nucleolar ribonucleoproteins play a critical role in maintaining the stability and functionality of rRNAs and snRNAs, which are essential components of the translation and splicing machinery in eukaryotic cells.

The nucleolus is a structure found within the nucleus of eukaryotic cells (cells that contain a true nucleus). It plays a central role in the production and assembly of ribosomes, which are complex molecular machines responsible for protein synthesis. The nucleolus is not a distinct organelle with a membrane surrounding it, but rather a condensed region within the nucleus where ribosomal biogenesis takes place.

The process of ribosome formation begins in the nucleolus with the transcription of ribosomal DNA (rDNA) genes into long precursor RNA molecules called rRNAs (ribosomal RNAs). Within the nucleolus, these rRNA molecules are cleaved, modified, and assembled together with ribosomal proteins to form small and large ribosomal subunits. Once formed, these subunits are transported through the nuclear pores to the cytoplasm, where they come together to form functional ribosomes that can engage in protein synthesis.

In addition to its role in ribosome biogenesis, the nucleolus has been implicated in other cellular processes such as stress response, cell cycle regulation, and aging. Changes in nucleolar structure and function have been associated with various diseases, including cancer and neurodegenerative disorders.

CREB (Cyclic AMP Response Element-Binding Protein) is a transcription factor that plays a crucial role in regulating gene expression in response to various cellular signals. CREB binds to the cAMP response element (CRE) sequence in the promoter region of target genes and regulates their transcription.

When activated, CREB undergoes phosphorylation at a specific serine residue (Ser-133), which leads to its binding to the coactivator protein CBP/p300 and recruitment of additional transcriptional machinery to the promoter region. This results in the activation of target gene transcription.

CREB is involved in various cellular processes, including metabolism, differentiation, survival, and memory formation. Dysregulation of CREB has been implicated in several diseases, such as cancer, neurodegenerative disorders, and mood disorders.

Protein methyltransferases (PMTs) are a family of enzymes that transfer methyl groups from a donor, such as S-adenosylmethionine (SAM), to specific residues on protein substrates. This post-translational modification plays a crucial role in various cellular processes, including epigenetic regulation, signal transduction, and protein stability.

PMTs can methylate different amino acid residues, such as lysine, arginine, and histidine, on proteins. The methylation of these residues can lead to changes in the charge, hydrophobicity, or interaction properties of the target protein, thereby modulating its function.

For example, lysine methyltransferases (KMTs) are a subclass of PMTs that specifically methylate lysine residues on histone proteins, which are the core components of nucleosomes in chromatin. Histone methylation can either activate or repress gene transcription, depending on the specific residue and degree of methylation.

Protein arginine methyltransferases (PRMTs) are another subclass of PMTs that methylate arginine residues on various protein substrates, including histones, transcription factors, and RNA-binding proteins. Arginine methylation can also affect protein function by altering its interaction with other molecules or modulating its stability.

Overall, protein methyltransferases are essential regulators of cellular processes and have been implicated in various diseases, including cancer, neurodegenerative disorders, and cardiovascular diseases. Therefore, understanding the mechanisms and functions of PMTs is crucial for developing novel therapeutic strategies to target these diseases.

Autoantibodies are defined as antibodies that are produced by the immune system and target the body's own cells, tissues, or organs. These antibodies mistakenly identify certain proteins or molecules in the body as foreign invaders and attack them, leading to an autoimmune response. Autoantibodies can be found in various autoimmune diseases such as rheumatoid arthritis, lupus, and thyroiditis. The presence of autoantibodies can also be used as a diagnostic marker for certain conditions.

Genetic transcription is the process by which the information in a strand of DNA is used to create a complementary RNA molecule. This process is the first step in gene expression, where the genetic code in DNA is converted into a form that can be used to produce proteins or functional RNAs.

During transcription, an enzyme called RNA polymerase binds to the DNA template strand and reads the sequence of nucleotide bases. As it moves along the template, it adds complementary RNA nucleotides to the growing RNA chain, creating a single-stranded RNA molecule that is complementary to the DNA template strand. Once transcription is complete, the RNA molecule may undergo further processing before it can be translated into protein or perform its functional role in the cell.

Transcription can be either "constitutive" or "regulated." Constitutive transcription occurs at a relatively constant rate and produces essential proteins that are required for basic cellular functions. Regulated transcription, on the other hand, is subject to control by various intracellular and extracellular signals, allowing cells to respond to changing environmental conditions or developmental cues.

A precipitin test is a type of immunodiagnostic test used to detect and measure the presence of specific antibodies or antigens in a patient's serum. The test is based on the principle of antigen-antibody interaction, where the addition of an antigen to a solution containing its corresponding antibody results in the formation of an insoluble immune complex known as a precipitin.

In this test, a small amount of the patient's serum is added to a solution containing a known antigen or antibody. If the patient has antibodies or antigens that correspond to the added reagent, they will bind and form a visible precipitate. The size and density of the precipitate can be used to quantify the amount of antibody or antigen present in the sample.

Precipitin tests are commonly used in the diagnosis of various infectious diseases, autoimmune disorders, and allergies. They can also be used in forensic science to identify biological samples. However, they have largely been replaced by more modern immunological techniques such as enzyme-linked immunosorbent assays (ELISAs) and radioimmunoassays (RIAs).

Systemic Lupus Erythematosus (SLE) is a complex autoimmune disease that can affect almost any organ or system in the body. In SLE, the immune system produces an exaggerated response, leading to the production of autoantibodies that attack the body's own cells and tissues, causing inflammation and damage. The symptoms and severity of SLE can vary widely from person to person, but common features include fatigue, joint pain, skin rashes (particularly a "butterfly" rash across the nose and cheeks), fever, hair loss, and sensitivity to sunlight.

Systemic lupus erythematosus can also affect the kidneys, heart, lungs, brain, blood vessels, and other organs, leading to a wide range of symptoms such as kidney dysfunction, chest pain, shortness of breath, seizures, and anemia. The exact cause of SLE is not fully understood, but it is believed to involve a combination of genetic, environmental, and hormonal factors. Treatment typically involves medications to suppress the immune system and manage symptoms, and may require long-term management by a team of healthcare professionals.

Nucleic acid conformation refers to the three-dimensional structure that nucleic acids (DNA and RNA) adopt as a result of the bonding patterns between the atoms within the molecule. The primary structure of nucleic acids is determined by the sequence of nucleotides, while the conformation is influenced by factors such as the sugar-phosphate backbone, base stacking, and hydrogen bonding.

Two common conformations of DNA are the B-form and the A-form. The B-form is a right-handed helix with a diameter of about 20 Å and a pitch of 34 Å, while the A-form has a smaller diameter (about 18 Å) and a shorter pitch (about 25 Å). RNA typically adopts an A-form conformation.

The conformation of nucleic acids can have significant implications for their function, as it can affect their ability to interact with other molecules such as proteins or drugs. Understanding the conformational properties of nucleic acids is therefore an important area of research in molecular biology and medicine.

Cytoplasm is the material within a eukaryotic cell (a cell with a true nucleus) that lies between the nuclear membrane and the cell membrane. It is composed of an aqueous solution called cytosol, in which various organelles such as mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles are suspended. Cytoplasm also contains a variety of dissolved nutrients, metabolites, ions, and enzymes that are involved in various cellular processes such as metabolism, signaling, and transport. It is where most of the cell's metabolic activities take place, and it plays a crucial role in maintaining the structure and function of the cell.

Sequence homology, amino acid, refers to the similarity in the order of amino acids in a protein or a portion of a protein between two or more species. This similarity can be used to infer evolutionary relationships and functional similarities between proteins. The higher the degree of sequence homology, the more likely it is that the proteins are related and have similar functions. Sequence homology can be determined through various methods such as pairwise alignment or multiple sequence alignment, which compare the sequences and calculate a score based on the number and type of matching amino acids.

Alternative splicing is a process in molecular biology that occurs during the post-transcriptional modification of pre-messenger RNA (pre-mRNA) molecules. It involves the removal of non-coding sequences, known as introns, and the joining together of coding sequences, or exons, to form a mature messenger RNA (mRNA) molecule that can be translated into a protein.

In alternative splicing, different combinations of exons are selected and joined together to create multiple distinct mRNA transcripts from a single pre-mRNA template. This process increases the diversity of proteins that can be produced from a limited number of genes, allowing for greater functional complexity in organisms.

Alternative splicing is regulated by various cis-acting elements and trans-acting factors that bind to specific sequences in the pre-mRNA molecule and influence which exons are included or excluded during splicing. Abnormal alternative splicing has been implicated in several human diseases, including cancer, neurological disorders, and cardiovascular disease.

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

In the context of medical and biological sciences, a "binding site" refers to a specific location on a protein, molecule, or cell where another molecule can attach or bind. This binding interaction can lead to various functional changes in the original protein or molecule. The other molecule that binds to the binding site is often referred to as a ligand, which can be a small molecule, ion, or even another protein.

The binding between a ligand and its target binding site can be specific and selective, meaning that only certain ligands can bind to particular binding sites with high affinity. This specificity plays a crucial role in various biological processes, such as signal transduction, enzyme catalysis, or drug action.

In the case of drug development, understanding the location and properties of binding sites on target proteins is essential for designing drugs that can selectively bind to these sites and modulate protein function. This knowledge can help create more effective and safer therapeutic options for various diseases.

Methylation, in the context of genetics and epigenetics, refers to the addition of a methyl group (CH3) to a molecule, usually to the nitrogenous base of DNA or to the side chain of amino acids in proteins. In DNA methylation, this process typically occurs at the 5-carbon position of cytosine residues that precede guanine residues (CpG sites) and is catalyzed by enzymes called DNA methyltransferases (DNMTs).

DNA methylation plays a crucial role in regulating gene expression, genomic imprinting, X-chromosome inactivation, and suppression of repetitive elements. Hypermethylation or hypomethylation of specific genes can lead to altered gene expression patterns, which have been associated with various human diseases, including cancer.

In summary, methylation is a fundamental epigenetic modification that influences genomic stability, gene regulation, and cellular function by introducing methyl groups to DNA or proteins.

Immunoprecipitation (IP) is a research technique used in molecular biology and immunology to isolate specific antigens or antibodies from a mixture. It involves the use of an antibody that recognizes and binds to a specific antigen, which is then precipitated out of solution using various methods, such as centrifugation or chemical cross-linking.

In this technique, an antibody is first incubated with a sample containing the antigen of interest. The antibody specifically binds to the antigen, forming an immune complex. This complex can then be captured by adding protein A or G agarose beads, which bind to the constant region of the antibody. The beads are then washed to remove any unbound proteins, leaving behind the precipitated antigen-antibody complex.

Immunoprecipitation is a powerful tool for studying protein-protein interactions, post-translational modifications, and signal transduction pathways. It can also be used to detect and quantify specific proteins in biological samples, such as cells or tissues, and to identify potential biomarkers of disease.

Exons are the coding regions of DNA that remain in the mature, processed mRNA after the removal of non-coding intronic sequences during RNA splicing. These exons contain the information necessary to encode proteins, as they specify the sequence of amino acids within a polypeptide chain. The arrangement and order of exons can vary between different genes and even between different versions of the same gene (alternative splicing), allowing for the generation of multiple protein isoforms from a single gene. This complexity in exon structure and usage significantly contributes to the diversity and functionality of the proteome.

"Poly A" is an abbreviation for "poly(A) tail" or "polyadenylation." It refers to the addition of multiple adenine (A) nucleotides to the 3' end of eukaryotic mRNA molecules during the process of transcription. This poly(A) tail plays a crucial role in various aspects of mRNA metabolism, including stability, transport, and translation. The length of the poly(A) tail can vary from around 50 to 250 nucleotides depending on the cell type and developmental stage.

Protein biosynthesis is the process by which cells generate new proteins. It involves two major steps: transcription and translation. Transcription is the process of creating a complementary RNA copy of a sequence of DNA. This RNA copy, or messenger RNA (mRNA), carries the genetic information to the site of protein synthesis, the ribosome. During translation, the mRNA is read by transfer RNA (tRNA) molecules, which bring specific amino acids to the ribosome based on the sequence of nucleotides in the mRNA. The ribosome then links these amino acids together in the correct order to form a polypeptide chain, which may then fold into a functional protein. Protein biosynthesis is essential for the growth and maintenance of all living organisms.

Nerve tissue proteins are specialized proteins found in the nervous system that provide structural and functional support to nerve cells, also known as neurons. These proteins include:

1. Neurofilaments: These are type IV intermediate filaments that provide structural support to neurons and help maintain their shape and size. They are composed of three subunits - NFL (light), NFM (medium), and NFH (heavy).

2. Neuronal Cytoskeletal Proteins: These include tubulins, actins, and spectrins that provide structural support to the neuronal cytoskeleton and help maintain its integrity.

3. Neurotransmitter Receptors: These are specialized proteins located on the postsynaptic membrane of neurons that bind neurotransmitters released by presynaptic neurons, triggering a response in the target cell.

4. Ion Channels: These are transmembrane proteins that regulate the flow of ions across the neuronal membrane and play a crucial role in generating and transmitting electrical signals in neurons.

5. Signaling Proteins: These include enzymes, receptors, and adaptor proteins that mediate intracellular signaling pathways involved in neuronal development, differentiation, survival, and death.

6. Adhesion Proteins: These are cell surface proteins that mediate cell-cell and cell-matrix interactions, playing a crucial role in the formation and maintenance of neural circuits.

7. Extracellular Matrix Proteins: These include proteoglycans, laminins, and collagens that provide structural support to nerve tissue and regulate neuronal migration, differentiation, and survival.

Saccharomyces cerevisiae proteins are the proteins that are produced by the budding yeast, Saccharomyces cerevisiae. This organism is a single-celled eukaryote that has been widely used as a model organism in scientific research for many years due to its relatively simple genetic makeup and its similarity to higher eukaryotic cells.

The genome of Saccharomyces cerevisiae has been fully sequenced, and it is estimated to contain approximately 6,000 genes that encode proteins. These proteins play a wide variety of roles in the cell, including catalyzing metabolic reactions, regulating gene expression, maintaining the structure of the cell, and responding to environmental stimuli.

Many Saccharomyces cerevisiae proteins have human homologs and are involved in similar biological processes, making this organism a valuable tool for studying human disease. For example, many of the proteins involved in DNA replication, repair, and recombination in yeast have human counterparts that are associated with cancer and other diseases. By studying these proteins in yeast, researchers can gain insights into their function and regulation in humans, which may lead to new treatments for disease.

Molecular weight, also known as molecular mass, is the mass of a molecule. It is expressed in units of atomic mass units (amu) or daltons (Da). Molecular weight is calculated by adding up the atomic weights of each atom in a molecule. It is a useful property in chemistry and biology, as it can be used to determine the concentration of a substance in a solution, or to calculate the amount of a substance that will react with another in a chemical reaction.

Electrophoresis, polyacrylamide gel (EPG) is a laboratory technique used to separate and analyze complex mixtures of proteins or nucleic acids (DNA or RNA) based on their size and electrical charge. This technique utilizes a matrix made of cross-linked polyacrylamide, a type of gel, which provides a stable and uniform environment for the separation of molecules.

In this process:

1. The polyacrylamide gel is prepared by mixing acrylamide monomers with a cross-linking agent (bis-acrylamide) and a catalyst (ammonium persulfate) in the presence of a buffer solution.
2. The gel is then poured into a mold and allowed to polymerize, forming a solid matrix with uniform pore sizes that depend on the concentration of acrylamide used. Higher concentrations result in smaller pores, providing better resolution for separating smaller molecules.
3. Once the gel has set, it is placed in an electrophoresis apparatus containing a buffer solution. Samples containing the mixture of proteins or nucleic acids are loaded into wells on the top of the gel.
4. An electric field is applied across the gel, causing the negatively charged molecules to migrate towards the positive electrode (anode) while positively charged molecules move toward the negative electrode (cathode). The rate of migration depends on the size, charge, and shape of the molecules.
5. Smaller molecules move faster through the gel matrix and will migrate farther from the origin compared to larger molecules, resulting in separation based on size. Proteins and nucleic acids can be selectively stained after electrophoresis to visualize the separated bands.

EPG is widely used in various research fields, including molecular biology, genetics, proteomics, and forensic science, for applications such as protein characterization, DNA fragment analysis, cloning, mutation detection, and quality control of nucleic acid or protein samples.

A viral RNA (ribonucleic acid) is the genetic material found in certain types of viruses, as opposed to viruses that contain DNA (deoxyribonucleic acid). These viruses are known as RNA viruses. The RNA can be single-stranded or double-stranded and can exist as several different forms, such as positive-sense, negative-sense, or ambisense RNA. Upon infecting a host cell, the viral RNA uses the host's cellular machinery to translate the genetic information into proteins, leading to the production of new virus particles and the continuation of the viral life cycle. Examples of human diseases caused by RNA viruses include influenza, COVID-19 (SARS-CoV-2), hepatitis C, and polio.

"Saccharomyces cerevisiae" is not typically considered a medical term, but it is a scientific name used in the field of microbiology. It refers to a species of yeast that is commonly used in various industrial processes, such as baking and brewing. It's also widely used in scientific research due to its genetic tractability and eukaryotic cellular organization.

However, it does have some relevance to medical fields like medicine and nutrition. For example, certain strains of S. cerevisiae are used as probiotics, which can provide health benefits when consumed. They may help support gut health, enhance the immune system, and even assist in the digestion of certain nutrients.

In summary, "Saccharomyces cerevisiae" is a species of yeast with various industrial and potential medical applications.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

Introns are non-coding sequences of DNA that are present within the genes of eukaryotic organisms, including plants, animals, and humans. Introns are removed during the process of RNA splicing, in which the initial RNA transcript is cut and reconnected to form a mature, functional RNA molecule.

After the intron sequences are removed, the remaining coding sequences, known as exons, are joined together to create a continuous stretch of genetic information that can be translated into a protein or used to produce non-coding RNAs with specific functions. The removal of introns allows for greater flexibility in gene expression and regulation, enabling the generation of multiple proteins from a single gene through alternative splicing.

In summary, introns are non-coding DNA sequences within genes that are removed during RNA processing to create functional RNA molecules or proteins.

'Artemia' is a genus of aquatic branchiopod crustaceans, also known as brine shrimp. They are commonly found in saltwater environments such as salt lakes and highly saline ponds. Artemia are known for their ability to produce cysts (also called "resting eggs") that can survive extreme environmental conditions, making them an important organism in research related to survival in harsh environments and space exploration.

In a medical context, Artemia is not typically used as a term but may be referenced in scientific studies related to biology, genetics, or astrobiology. The compounds derived from Artemia, such as astaxanthin and other carotenoids, have been studied for their potential health benefits, including antioxidant properties and support for eye and heart health. However, these applications are still under research and not yet considered part of mainstream medical practice.

'Drosophila melanogaster' is the scientific name for a species of fruit fly that is commonly used as a model organism in various fields of biological research, including genetics, developmental biology, and evolutionary biology. Its small size, short generation time, large number of offspring, and ease of cultivation make it an ideal subject for laboratory studies. The fruit fly's genome has been fully sequenced, and many of its genes have counterparts in the human genome, which facilitates the understanding of genetic mechanisms and their role in human health and disease.

Here is a brief medical definition:

Drosophila melanogaster (droh-suh-fih-luh meh-lon-guh-ster): A species of fruit fly used extensively as a model organism in genetic, developmental, and evolutionary research. Its genome has been sequenced, revealing many genes with human counterparts, making it valuable for understanding genetic mechanisms and their role in human health and disease.

The Fluorescent Antibody Technique (FAT) is a type of immunofluorescence assay used in laboratory medicine and pathology for the detection and localization of specific antigens or antibodies in tissues, cells, or microorganisms. In this technique, a fluorescein-labeled antibody is used to selectively bind to the target antigen or antibody, forming an immune complex. When excited by light of a specific wavelength, the fluorescein label emits light at a longer wavelength, typically visualized as green fluorescence under a fluorescence microscope.

The FAT is widely used in diagnostic microbiology for the identification and characterization of various bacteria, viruses, fungi, and parasites. It has also been applied in the diagnosis of autoimmune diseases and certain cancers by detecting specific antibodies or antigens in patient samples. The main advantage of FAT is its high sensitivity and specificity, allowing for accurate detection and differentiation of various pathogens and disease markers. However, it requires specialized equipment and trained personnel to perform and interpret the results.

Heterogeneous nuclear ribonucleoprotein A3 is a protein that in humans is encoded by the HNRNPA3 gene. GRCh38: Ensembl release ... "Entrez Gene: HNRPA3 heterogeneous nuclear ribonucleoprotein A3". Lairmore TC, Dou S, Howe JR, et al. (1993). "A 1.5-megabase ... Ma AS, Moran-Jones K, Shan J, Munro TP, Snee MJ, Hoek KS, Smith R (May 2002). "Heterogeneous nuclear ribonucleoprotein A3, a ... 1993). "Identification and characterization of a cDNA, which is highly homologous to the ribonucleoprotein gene, from a locus ( ...
Heterogeneous nuclear ribonucleoprotein H3 is a protein that in humans is encoded by the HNRNPH3 gene. This gene belongs to the ... "Entrez Gene: HNRPH3 heterogeneous nuclear ribonucleoprotein H3 (2H9)". Rasmussen HH, van Damme J, Puype M, et al. (1993). " ... "Cloning of human 2H9 heterogeneous nuclear ribonucleoproteins. Relation with splicing and early heat shock-induced splicing ... subfamily of ubiquitously expressed heterogeneous nuclear ribonucleoproteins (hnRNPs). The hnRNPs are RNA binding proteins and ...
Heterogeneous nuclear ribonucleoprotein K and Y-box-binding protein". J. Biol. Chem. 275 (20): 15498-503. doi:10.1074/jbc. ...
HNRPA2B1 heterogeneous nuclear ribonucleoprotein A2/B1". "HNRNPA2B1 heterogeneous nuclear ribonucleoprotein A2/B1 [Homo sapiens ... Heterogeneous nuclear ribonucleoproteins A2/B1 is a protein that in humans is encoded by the HNRNPA2B1 gene. HNRNPA2B1 gene ... Pancetti F, Bosser R, Krehan A, Pyerin W, Itarte E, Bachs O (June 1999). "Heterogeneous nuclear ribonucleoprotein A2 interacts ... Pancetti F, Bosser R, Krehan A, Pyerin W, Itarte E, Bachs O (1999). "Heterogeneous nuclear ribonucleoprotein A2 interacts with ...
This gene encodes a nuclear RNA-binding protein of the heterogeneous nuclear ribonucleoprotein (hnRNP) family. This protein ... Heterogeneous nuclear ribonucleoprotein U-like protein 1 is a protein that in humans is encoded by the HNRNPUL1 gene. ... 2001). "Heterogeneous nuclear ribonucleoprotein E1B-AP5 is methylated in its Arg-Gly-Gly (RGG) box and interacts with human ... "Entrez Gene: HNRPUL1 heterogeneous nuclear ribonucleoprotein U-like 1". Kzhyshkowska, J; Schütt H; Liss M; Kremmer E; Stauber R ...
Heterogeneous nuclear ribonucleoprotein L is a protein that in humans is encoded by the HNRNPL gene. Heterogeneous nuclear RNAs ... Heterogeneous nuclear ribonucleoprotein L is present in the nucleoplasm as part of the HNRP complex. HNRP proteins have also ... "Entrez Gene: HNRPL heterogeneous nuclear ribonucleoprotein L". Oberdoerffer S, Moita LF, Neems D, Freitas RP, Hacohen N, Rao A ... Heterogeneous nuclear ribonucleoprotein L is among the proteins that are stably associated with hnRNP complexes and along with ...
It is from heterogeneous nuclear ribonucleoprotein (hnRNP) K. Therefore, binding domains that belong to this family are called ... Swanson MS, Dreyfuss G, Pinol-Roma S (1988). "Heterogeneous nuclear ribonucleoprotein particles and the pathway of mRNA ... Matera, A. Gregory; Terns, Rebecca M.; Terns, Michael P. (March 2007). "Non-coding RNAs: lessons from the small nuclear and ...
Heterogeneous nuclear ribonucleoprotein L-like is a protein that in humans is encoded by the HNRNPLL gene. HNRNPLL is a master ... "Entrez Gene: Heterogeneous nuclear ribonucleoprotein L-like". Oberdoerffer S, Moita LF, Neems D, Freitas RP, Hacohen N, Rao A ( ... and RC isoforms for TCR signaling and peripheral T cell deficiency resulting from heterogeneous nuclear ribonucleoprotein L- ... August 2008). "Regulation of CD45 alternative splicing by heterogeneous ribonucleoprotein, hnRNPLL". Science. 321 (5889): 686- ...
HNRPA1 heterogeneous nuclear ribonucleoprotein A1". Kaur R, Lal SK (March 2020). "The multifarious roles of heterogeneous ... Heterogeneous nuclear ribonucleoprotein A1 is a protein that in humans is encoded by the HNRNPA1 gene. Mutations in hnRNP A1 ... Hamilton BJ, Nagy E, Malter JS, Arrick BA, Rigby WF (1993). "Association of heterogeneous nuclear ribonucleoprotein A1 and C ... This gene belongs to the A/B subfamily of ubiquitously expressed heterogeneous nuclear ribonucleoproteins (hnRNPs). The hnRNPs ...
Heterogeneous nuclear ribonucleoprotein A0 is a protein that in humans is encoded by the HNRNPA0 gene. This gene belongs to the ... "Entrez Gene: HNRPA0 heterogeneous nuclear ribonucleoprotein A0". Dawson SJ, White LA (1992). "Treatment of Haemophilus ... A/B subfamily of ubiquitously expressed heterogeneous nuclear ribonucleoproteins (hnRNPs). The hnRNPs are RNA binding proteins ... and they complex with heterogeneous nuclear RNA (hnRNA). These proteins are associated with pre-mRNAs in the nucleus and appear ...
Heterogeneous nuclear ribonucleoprotein K (also protein K) is a protein that in humans is encoded by the HNRNPK gene. It is ... "Entrez Gene: HNRPK heterogeneous nuclear ribonucleoprotein K". Gallardo M, Lee HJ, Zhang X, Bueso-Ramos C, Pageon LR, McArthur ... Heterogeneous nuclear ribonucleoprotein K and Y-box-binding protein". The Journal of Biological Chemistry. 275 (20): 15498-503 ... Miau LH, Chang CJ, Shen BJ, Tsai WH, Lee SC (April 1998). "Identification of heterogeneous nuclear ribonucleoprotein K (hnRNP K ...
Heterogeneous nuclear ribonucleoprotein D-like, also known as HNRPDL, is a protein which in humans is encoded by the HNRPDL ... "Entrez Gene: HNRPDL heterogeneous nuclear ribonucleoprotein D-like". Doi A, Shiosaka T, Takaoka Y, et al. (1998). "Molecular ... 1999). "Two forms of expression and genomic structure of the human heterogeneous nuclear ribonucleoprotein D-like JKTBP gene ( ... 1998). "Cloning and characterization of a cDNA encoding a novel heterogeneous nuclear ribonucleoprotein-like protein and its ...
Heterogeneous nuclear ribonucleoprotein K and Y-box-binding protein". J. Biol. Chem. 275 (20): 15498-503. doi:10.1074/jbc. ... "The tight junction protein ZO-2 localizes to the nucleus and interacts with the heterogeneous nuclear ribonucleoprotein ... the nuclear matrix, or both. Scaffold attachment factors are a subset of nuclear matrix proteins (NMP) with enriched binding to ... a novel nuclear DNA binding protein from HeLa cells with high affinity for nuclear matrix/scaffold attachment DNA elements". ...
Heterogeneous nuclear ribonucleoprotein A/B, also known as HNRNPAB, is a protein which in humans is encoded by the HNRNPAB gene ... "HNRNPAB heterogeneous nuclear ribonucleoprotein A/B [ Homo sapiens (human) ]". Khan FA, Jaiswal AK, Szer W (September 1991). " ... Gao C, Guo H, Wei J, Mi Z, Wai P, Kuo PC (March 2004). "S-nitrosylation of heterogeneous nuclear ribonucleoprotein A/B ... This gene belongs to the subfamily of ubiquitously expressed heterogeneous nuclear ribonucleoproteins (hnRNPs). The hnRNPs are ...
"Entrez Gene: HNRPC heterogeneous nuclear ribonucleoprotein C (C1/C2)". Zhang Y, Zhang YL, Feng C, Wu YT, Liu AX, Sheng JZ, Cai ... Heterogeneous nuclear ribonucleoproteins C1/C2 is a protein that in humans is encoded by the HNRNPC gene. It is abnormally ... Hamilton BJ, Nagy E, Malter JS, Arrick BA, Rigby WF (1993). "Association of heterogeneous nuclear ribonucleoprotein A1 and C ... Burd CG, Swanson MS, Görlach M, Dreyfuss G (1990). "Primary structures of the heterogeneous nuclear ribonucleoprotein A2, B1, ...
Pancetti F, Bosser R, Krehan A, Pyerin W, Itarte E, Bachs O (June 1999). "Heterogeneous nuclear ribonucleoprotein A2 interacts ...
This gene belongs to the subfamily of ubiquitously expressed heterogeneous nuclear ribonucleoproteins (hnRNPs). The hnRNPs are ... "Organization of the human gene encoding heterogeneous nuclear ribonucleoprotein type I (hnRNP I) and characterization of hnRNP ... "Assignment of the human gene encoding heterogeneous nuclear RNA ribonucleoprotein I (PTB) to chromosome 14q23-q24.1". Genomics ... Meissner M, Dechat T, Gerner C, Grimm R, Foisner R, Sauermann G (January 2000). "Differential nuclear localization and nuclear ...
Heterogeneous nuclear ribonucleoprotein F is a protein that in humans is encoded by the HNRNPF gene. This gene belongs to the ... 2000). "Heterogeneous nuclear RNA-ribonucleoprotein F binds to DNA via an oligo(dG)-motif and is associated with RNA polymerase ... "Entrez Gene: HNRPF heterogeneous nuclear ribonucleoprotein F". McDonald H, Smailus D, Jenkins H, et al. (1992). "Identification ... Honoré B, Baandrup U, Vorum H (2004). "Heterogeneous nuclear ribonucleoproteins F and H/H' show differential expression in ...
Vincendeau M, Nagel D, Brenke JK, Brack-Werner R, Hadian K (2013). "Heterogenous nuclear ribonucleoprotein Q increases protein ... Harris CE, Boden RA, Astell CR (January 1999). "A novel heterogeneous nuclear ribonucleoprotein-like protein interacts with NS1 ... This gene belongs to the subfamily of ubiquitously expressed heterogeneous nuclear ribonucleoproteins (hnRNPs). The hnRNPs are ... Synaptotagmin-binding, cytoplasmic RNA-interacting protein (SYNCRIP), also known as heterogeneous nuclear ribonucleoprotein ( ...
Heterogeneous nuclear ribonucleoprotein H2 is a protein that in humans is encoded by the HNRNPH2 gene. This gene belongs to the ... "Entrez Gene: HNRPH2 heterogeneous nuclear ribonucleoprotein H2 (H')". Vorechovský I, Vetrie D, Holland J, et al. (1994). " ... Honoré B, Baandrup U, Vorum H (2004). "Heterogeneous nuclear ribonucleoproteins F and H/H' show differential expression in ... Caputi M, Zahler AM (2001). "Determination of the RNA binding specificity of the heterogeneous nuclear ribonucleoprotein (hnRNP ...
Heterogeneous nuclear ribonucleoprotein R is a protein that in humans is encoded by the HNRNPR gene. This gene belongs to the ... "Entrez Gene: HNRPR heterogeneous nuclear ribonucleoprotein R". Briese M, Saal-Bauernschubert L, Ji C, Moradi M, Ghanawi H, Uhl ... Huang J, Chen XH, Wu K, Xu P (May 2005). "Cloning and expression of a novel isoform of heterogeneous nuclear ribonucleoprotein- ... Glinka M, Herrmann T, Funk N, Havlicek S, Rossoll W, Winkler C, Sendtner M (2010). "The heterogeneous nuclear ribonucleoprotein ...
Heterogeneous nuclear ribonucleoprotein U is a protein that in humans is encoded by the HNRNPU gene. This gene belongs to the ... "Entrez Gene: HNRNPU heterogeneous nuclear ribonucleoprotein U (scaffold attachment factor A)". Martens JH, Verlaan M, Kalkhoven ... "The class III POU factor Brn-4 interacts with other class III POU factors and the heterogeneous nuclear ribonucleoprotein U." ... Taniura H, Yoshikawa K (2002). "Necdin interacts with the ribonucleoprotein hnRNP U in the nuclear matrix". J. Cell. Biochem. ...
Heterogeneous nuclear ribonucleoprotein D0 (HNRNPD) also known as AU-rich element RNA-binding protein 1 (AUF1) is a protein ... "Entrez Gene: HNRPD heterogeneous nuclear ribonucleoprotein D (AU-rich element RNA binding protein 1, 37kDa)". Mazan-Mamczarz K ... Tay N, Chan SH, Ren EC (1992). "Identification and cloning of a novel heterogeneous nuclear ribonucleoprotein C-like protein ... Kiledjian M, DeMaria CT, Brewer G, Novick K (1997). "Identification of AUF1 (heterogeneous nuclear ribonucleoprotein D) as a ...
Heterogeneous nuclear ribonucleoprotein H is a protein that in humans is encoded by the HNRNPH1 gene. This gene belongs to the ... "Entrez Gene: HNRPH1 heterogeneous nuclear ribonucleoprotein H1 (H)". Rasmussen HH, van Damme J, Puype M, et al. (1993). " ... Honoré B, Baandrup U, Vorum H (2004). "Heterogeneous nuclear ribonucleoproteins F and H/H' show differential expression in ... "Heterogeneous nuclear ribonucleoproteins H, H', and F are members of a ubiquitously expressed subfamily of related but distinct ...
RRM proteins have a variety of RNA binding preferences and functions, and include heterogeneous nuclear ribonucleoproteins ( ... "Heterogeneous nuclear ribonucleoprotein particles and the pathway of mRNA formation". Trends Biochem. Sci. 13 (3): 86-91. doi: ... protein components of small nuclear ribonucleoproteins (U1 and U2 snRNPs), and proteins that regulate RNA stability and ...
... a cytoplasmic counterpart of heterogeneous nuclear ribonucleoprotein R, interacts with ubiquitous synaptotagmin isoforms". The ... a cytoplasmic counterpart of heterogeneous nuclear ribonucleoprotein R, interacts with ubiquitous synaptotagmin isoforms". The ...
... a cytoplasmic counterpart of heterogeneous nuclear ribonucleoprotein R, interacts with ubiquitous synaptotagmin isoforms". The ... a cytoplasmic counterpart of heterogeneous nuclear ribonucleoprotein R, interacts with ubiquitous synaptotagmin isoforms". The ...
"Homo sapiens heterogeneous nuclear ribonucleoprotein H2 (HNRNPH2), transcript variant 1, mRNA". 21 October 2018. Bain, JM; Cho ... This gene (GenBank: NM_019597.4) encodes a member of a family of ubiquitous heterogeneous nuclear ribonucleoproteins (HNRNP). ... These ribonucleoproteins act as a shuttle between the nucleus and the cytoplasm and act on pre-mRNA to positively or negatively ...
2000). "SYNCRIP, a cytoplasmic counterpart of heterogeneous nuclear ribonucleoprotein R, interacts with ubiquitous ...
However, this inhibition is only possible when the splice factor heterogenous nuclear ribonucleoprotein H (hnRNP H) maintains ... "Heterogeneous Nuclear Ribonucleoprotein H Blocks MST2-Mediated Apoptosis in Cancer Cells by Regulating a-raf Transcription". ...

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