messenger RNA

(noun)

RNA that encodes and carries information from DNA during transcription to sites of protein synthesis to undergo translation in order to yield a protein

Related Terms

Examples of messenger RNA in the following topics:

  • Antisense Agents

    • Antisense agents are short oligonucleotides that bind to target messenger RNA and inhibit protein synthesis.
    • Antisense agents are synthetic, single-stranded short sequences of DNA bases designed to hybridize to specific sequences of messenger RNA (mRNA) forming a duplex .
    • This DNA-RNA coupling attracts an endogenous nuclease, RNase H that destroys the bound RNA and frees the DNA antisense to rehybridize with another copy of mRNA.
    • When this agent binds to the pathogen DNA or messenger RNA, the biosynthesis of target proteins is disrupted.
    • Therefore, there are at least two ways in which antisense agents act to effectively reduce the amount of pathogenic protein being synthesized - RNase H based degradation of RNA and prevention of ribosomal assembly and translation.

  • Northern Blots

    • Northern blots allow investigators to determine messenger RNA molecular weight and sample content.
    • The Northern blot is a technique used in molecular biology research to study gene expression in a sample, through detection of RNA (or isolated messenger RNA ).
    • The major difference is that RNA, rather than DNA, is analyzed in the Northern blot.
    • Eukaryotic mRNA can then be isolated through the use of oligo (dT) cellulose chromatography to isolate only those RNAs with a poly(A) tail.
    • RNA samples are then separated by gel electrophoresis.

  • Unsticking Stuck Ribosomes

    • As a result it cannot eject the mRNA.
    • The proteins which freed the ribosome remain with the mRNA which targets the nonstop mRNA for recognition by RNA degradation pathway.
    • Trans-translation is a recently discovered pathway in E. coli, although it is not completely understood, it involves Transfer-messenger RNA (abbreviated tmRNA) which is a bacterial RNA molecule with dual tRNA-like and messenger RNA-like properties.
    • Subsequently, the ribosome moves from the 3' end of the truncated messenger RNA onto the tmRNA where it translates the codons of the tmRNA until the tmRNA stop codon is encountered.
    • A ribosome with its RNA binding sites, designated E, P, and A, is stuck near the 3' end of a broken mRNA.

  • Ribosomes

    • The purpose of the ribosome is to translate messenger RNA (mRNA) into proteins with the aid of tRNA.
    • The purpose of the ribosome is to translate messenger RNA (mRNA) to proteins with the aid of tRNA.
    • One is for the mRNA; the other two are for the tRNA.
    • The binding sites for tRNA are the A site, which holds the aminoacyl-tRNA complex, and the P site, which binds to the tRNA attached to the growing polypeptide chain .
    • The 50S subunit contains the 23S and 5S rRNA while the 30S subunit contains the 16S rRNA.

  • Viral Replication and Gene Expression

    • Replication also involves synthesis of viral messenger RNA (mRNA) from "early" genes (with exceptions for positive sense RNA viruses), viral protein synthesis, possible assembly of viral proteins, then viral genome replication mediated by early or regulatory protein expression.
    • Viruses that replicate via RNA intermediates need an RNA-dependent RNA-polymerase to replicate their RNA, but animal cells do not seem to possess a suitable enzyme.
    • Therefore, this type of animal RNA virus needs to code for an RNA-dependent RNA polymerase.
    • No viral proteins can be made until viral messenger RNA is available; thus, the nature of the RNA in the virion affects the strategy of the virus: In plus-stranded RNA viruses, the virion (genomic) RNA is the same sense as mRNA and so functions as mRNA.
    • One of these includes RNA-dependent RNA polymerase (RNA replicase), which copies the viral RNA to form a double-stranded replicative form, in turn this directs the formation of new virions.

  • RNA Regulation and Antisense RNA

    • Antisense RNAs are single-stranded RNA molecules that can bind and inhibit specific mRNA translation to protein.
    • There are specific types of RNA molecules that can be utilized to control gene regulation, including messenger RNAs (mRNAs), small RNAs such as microRNAs and lastly, antisense RNAs.
    • The following is a brief overview of antisense RNAs and their role in RNA regulation.
    • Antisense RNAs are single-stranded RNA molecules that exhibit a complementary relationship to specific mRNAs.
    • The antisense RNA can physically pair and bind to the complementary mRNA, thus inhibiting the ability of the mRNA to be processed in the translation machinery.

  • Viroids

    • Viroid RNA does not code for any protein.
    • The replication mechanism involves RNA polymerase II, an enzyme normally associated with synthesis of messenger RNA from DNA, which instead catalyzes "rolling circle" synthesis of new RNA using the viroid's RNA as template.
    • This reflects the fact that any siRNAs produced would have less complementary base pairing with target messenger RNA.
    • The viroid siRNAs actually contain sequences capable of complementary base pairing with the plant's own messenger RNAs and induction of degradation or inhibition of translation is what causes the classic viroid symptoms.
    • Pospiviroidae replication occurs in an asymmetric fashion via host cell RNA polymerase, RNase, and RNA ligase.

  • Inhibiting Nucleic Acid Synthesis

    • Antimicrobial drugs can target nucleic acid (either RNA or DNA) synthesis.
    • Prokaryotic transcription is the process in which messenger RNA transcripts of genetic material are produced for later translation into proteins.
    • For example, the antimicrobial rifampin binds to DNA-dependent RNA polymerase, thereby inhibiting the initiation of RNA transcription.
    • RNA Polymerase, an enzyme that produces RNA, from T. aquaticus pictured during elongation.
    • Portions of the enzyme were made transparent so as to make the path of RNA and DNA more clear.

  • Prokaryotic Transcription and Translation Are Coupled

    • Prokaryotic transcription is the process in which messenger RNA transcripts of genetic material in prokaryotes are produced, to be translated for the production of proteins.
    • RNA polymerase (RNAP) binds to one of several specificity factors, σ, to form a holoenzyme.
    • Two termination mechanisms are well known: Intrinsic termination (also called Rho-independent transcription termination) involves terminator sequences within the RNA that signal the RNA polymerase to stop.
    • This protein binds at a rho utilisation site on the nascent RNA strand and runs along the mRNA towards the RNAP.
    • This RNA is then subject to post-transcriptional modification and control, resulting in a mature mRNA (red) that is then transported out of the nucleus and into the cytoplasm (peach), where it undergoes translation into a protein. mRNA is translated by ribosomes (purple) that match the three-base codons of the mRNA to the three-base anti-codons of the appropriate tRNA.

  • Small Regulatory RNAs

    • Small regulatory RNAs encompass a specific class of RNAs that affect gene regulation.
    • Antisense RNAs are used to bind to complementary mRNAs and inhibit protein translation.
    • The antisense RNAs are categorized as small regulatory RNAs due to their small size.
    • Small regulatory RNAs encompass many RNAs involved in house-keeping processes as well.
    • The antisense RNA can bind to the mRNA and inhibit translation.