Ribonucleoprotein is a
nucleoproteinA nucleoprotein is any protein that is structurally associated with nucleic acid .Many viruses harness this protein, and they are known for being host-specific...
that contains
RNARibonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
, i.e. it is an association that combines ribonucleic acid and
proteinProteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
together. A few known examples include the
ribosomeA ribosome is a component of cells that assembles the twenty specific amino acid molecules to form the particular protein molecule determined by the nucleotide sequence of an RNA molecule....
, the enzyme
telomeraseTelomerase is an enzyme that adds DNA sequence repeats to the 3' end of DNA strands in the telomere regions, which are found at the ends of eukaryotic chromosomes. This region of repeated nucleotide called telomeres contains non-coding DNA material and prevents constant loss of important DNA from...
,
vault ribonucleoproteinsThe vault or vault cytoplasmic ribonucleoprotein is a eukaryotic organelle whose function is not fully understood. Discovered and successfully isolated by cell biologist Nancy Kedersha and biochemist Leonard Rome of the UCLA School of Medicine in the 1980s, vaults are cytoplasmic organelles which...
, and small nuclear RNPs (
snRNPsnRNPs , or small nuclear ribonucleoproteins, are RNA-protein complexes that combine with unmodified pre-mRNA and various other proteins to form a spliceosome, a large RNA-protein molecular complex upon which splicing of pre-mRNA occurs...
s), which are implicated in pre-mRNA
splicingIn molecular biology and genetics, splicing is a modification of an RNA after transcription, in which introns are removed and exons are joined. This is needed for the typical eukaryotic messenger RNA before it can be used to produce a correct protein through translation...
and are among the main components of the
nucleolusThe nucleolus is a non-membrane bound structure composed of proteins and nucleic acids found within the nucleus. Ribosomal RNA is transcribed and assembled within the nucleolus...
. 'RNP' can also refer to
ribonucleoprotein particlesA ribonucleoprotein particle or RNP is a complex formed between RNA and RNA-binding proteins . The term 'RNP foci' is also used to denote an intracellular compartment involved in processing of RNA transcripts.- RNA/RBP complexes :...
, distinct intracellular foci for
post-transcriptional regulationPost-transcriptional regulation is the control of gene expression at the RNA level, therefore between the transcription and the translation of the gene...
.
RNP in snRNPs has an RNA-binding
motifIn a chain-like biological molecule, such as a protein or nucleic acid, a structural motif is a supersecondary structure, which appears also in a variety of other molecules...
in its RNA-binding protein.
AromaticIn organic chemistry, Aromaticity is a chemical property in which a conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibit a stabilization stronger than would be expected by the stabilization of conjugation alone. The earliest use of the term was in an article by August...
amino acidAmino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
residues in this motif result in stacking interactions with RNA.
LysineLysine is an α-amino acid with the chemical formula HO2CCH4NH2. It is an essential amino acid, which means that the human body cannot synthesize it. Its codons are AAA and AAG....
residues in the
helicalA helix is a type of smooth space curve, i.e. a curve in three-dimensional space. It has the property that the tangent line at any point makes a constant angle with a fixed line called the axis. Examples of helixes are coil springs and the handrails of spiral staircases. A "filled-in" helix – for...
portion of RNA-binding proteins help to stabilize interactions with nucleic acids. This nucleic acid binding is strengthened by
electrostaticElectrostatics is the branch of physics that deals with the phenomena and properties of stationary or slow-moving electric charges....
attraction between the positive lysine
side chainIn organic chemistry and biochemistry, a side chain is a chemical group that is attached to a core part of the molecule called "main chain" or backbone. The placeholder R is often used as a generic placeholder for alkyl group side chains in chemical structure diagrams. To indicate other non-carbon...
s and the negative
nucleic acidNucleic acids are biological molecules essential for life, and include DNA and RNA . Together with proteins, nucleic acids make up the most important macromolecules; each is found in abundance in all living things, where they function in encoding, transmitting and expressing genetic information...
phosphateA phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
backbones.
RNPs play an important role in
influenzavirus AInfluenza A virus causes influenza in birds and some mammals and is the only species of Influenzavirus A. Influenzavirus A is a genus of the Orthomyxoviridae family of viruses. Strains of all subtypes of influenza A virus have been isolated from wild birds, although disease is uncommon...
replicationSelf-replication is any behavior of a dynamical system that yields construction of an identical copy of that dynamical system. Biological cells, given suitable environments, reproduce by cell division. During cell division, DNA is replicated and can be transmitted to offspring during reproduction...
. The
viralA virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
RNARibonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
is
transcribedTranscription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...
into
mRNAsMessenger RNA is a molecule of RNA encoding a chemical "blueprint" for a protein product. mRNA is transcribed from a DNA template, and carries coding information to the sites of protein synthesis: the ribosomes. Here, the nucleic acid polymer is translated into a polymer of amino acids: a protein...
by the
RNA polymeraseRNA polymerase is an enzyme that produces RNA. In cells, RNAP is needed for constructing RNA chains from DNA genes as templates, a process called transcription. RNA polymerase enzymes are essential to life and are found in all organisms and many viruses...
attached to the RNPs.
Anti-RNP antibodies
Anti-RNP antibodies are autoantibodies associated with
mixed connective tissue diseaseIn medicine, mixed connective tissue disease , commonly abbreviated as MCTD, is an autoimmune disease, in which the body's defense system attacks itself. It was characterized in 1972....
and are also detected in nearly 40% of
Lupus erythematosusLupus erythematosus is a category for a collection of diseases with similar underlying problems with immunity . Symptoms of these diseases can affect many different body systems, including joints, skin, kidneys, blood cells, heart, and lungs...
patients. Two types of anti-RNP antibodies are closely related to
Sjögren's syndromeSjögren's syndrome , also known as "Mikulicz disease" and "Sicca syndrome", is a systemic autoimmune disease in which immune cells attack and destroy the exocrine glands that produce tears and saliva....
: SS-A (Ro) and SS-B (La).
List of RNPs
This is a (partial) list of ribonucleoprotein families:
- hnRNP
- Ribosome
A ribosome is a component of cells that assembles the twenty specific amino acid molecules to form the particular protein molecule determined by the nucleotide sequence of an RNA molecule....
- snRNP
snRNPs , or small nuclear ribonucleoproteins, are RNA-protein complexes that combine with unmodified pre-mRNA and various other proteins to form a spliceosome, a large RNA-protein molecular complex upon which splicing of pre-mRNA occurs...
- Signal recognition particle
The signal recognition particle is an abundant, cytosolic, universally conserved ribonucleoprotein that recognizes and targets specific proteins to the endoplasmic reticulum in eukaryotes and the plasma membrane in prokaryotes....
(a protein coated ribozymeA ribozyme is an RNA molecule with a well defined tertiary structure that enables it to catalyze a chemical reaction. Ribozyme means ribonucleic acid enzyme. It may also be called an RNA enzyme or catalytic RNA. Many natural ribozymes catalyze either the hydrolysis of one of their own...
)
- Telomerase
Telomerase is an enzyme that adds DNA sequence repeats to the 3' end of DNA strands in the telomere regions, which are found at the ends of eukaryotic chromosomes. This region of repeated nucleotide called telomeres contains non-coding DNA material and prevents constant loss of important DNA from...