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Rna interference technology

In Structure and Function of RNA , we described the function of mRNA, rRNA, and tRNA. In addition to these types of RNA, cells also produce several types of small noncoding RNA molecules that are involved in the regulation of gene expression. These include antisense RNA molecules, which are complementary to regions of specific mRNA molecules found in both prokaryotes and eukaryotic cells. Non-coding RNA molecules play a major role in RNA interference (RNAi) , a natural regulatory mechanism by which mRNA molecules are prevented from guiding the synthesis of proteins. RNA interference of specific genes results from the base pairing of short, single-stranded antisense RNA molecules to regions within complementary mRNA molecules, preventing protein synthesis. Cells use RNA interference to protect themselves from viral invasion, which may introduce double-stranded RNA molecules as part of the viral replication process ( [link] ).

A eukaryotic cell transcribes a region of DNA into mrNA. Antisense mRNA then binds to the this mRNA to produce a double stranded region. This region is not translated (which means that ribosomes do not bind to the mRNA to produce proteins).
Cells like the eukaryotic cell shown in this diagram commonly make small antisense RNA molecules with sequences complementary to specific mRNA molecules. When an antisense RNA molecule is bound to an mRNA molecule, the mRNA can no longer be used to direct protein synthesis. (credit: modification of work by Robinson R)

Researchers are currently developing techniques to mimic the natural process of RNA interference as a way to treat viral infections in eukaryotic cells. RNA interference technology involves using small interfering RNAs (siRNAs) or microRNAs (miRNAs) ( [link] ). siRNAs are completely complementary to the mRNA transcript of a specific gene of interest while miRNAs are mostly complementary. These double-stranded RNAs are bound to DICER, an endonuclease that cleaves the RNA into short molecules (approximately 20 nucleotides long). The RNAs are then bound to RNA-induced silencing complex (RISC), a ribonucleoprotein. The siRNA-RISC complex binds to mRNA and cleaves it. For miRNA, only one of the two strands binds to RISC. The miRNA-RISC complex then binds to mRNA, inhibiting translation. If the miRNA is completely complementary to the target gene, then the mRNA can be cleaved. Taken together, these mechanisms are known as gene silencing .

Double stranded RNA can be produced from DNA in the nucleus. Dicer than cuts this dsRNA into either miRNA or siRNA. miRNA is an imperfect match and only one strand is usually incorporated into RISC. This blocks translation but the mRNA is stable. The RISC is stuck on the target. The siRNA has a perfect match and is incorporated into RISC. This triggers mRNA cleavage.
This diagram illustrates the process of using siRNA or miRNA in a eukaryotic cell to silence genes involved in the pathogenesis of various diseases. (credit: modification of work by National Center for Biotechnology Information)

Key concepts and summary

  • The science of genomics allows researchers to study organisms on a holistic level and has many applications of medical relevance.
  • Transcriptomics and proteomics allow researchers to compare gene expression patterns between different cells and shows great promise in better understanding global responses to various conditions.
  • The various –omics technologies complement each other and together provide a more complete picture of an organism’s or microbial community’s ( metagenomics ) state.
  • The analysis required for large data sets produced through genomics, transcriptomics, and proteomics has led to the emergence of bioinformatics .
  • Reporter genes encoding easily observable characteristics are commonly used to track gene expression patterns of genes of unknown function.
  • The use of recombinant DNA technology has revolutionized the pharmaceutical industry, allowing for the rapid production of high-quality recombinant DNA pharmaceuticals used to treat a wide variety of human conditions.
  • RNA interference technology has great promise as a method of treating viral infections by silencing the expression of specific genes

Fill in the blank

The application of genomics to evaluate the effectiveness and safety of drugs on the basis of information from an individual’s genomic sequence is called ____________.

pharmacogenomics or toxicogenomics

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A gene whose expression can be easily visualized and monitored is called a ________.

reporter gene

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True/false

RNA interference does not influence the sequence of genomic DNA.

true

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Short answer

If all cellular proteins are encoded by the cell’s genes, what information does proteomics provide that genomics cannot?

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Questions & Answers

what are the two acids the skin produce
Caro Reply
alpha hydroxy and beta hydroxy there are water soluble compounds and often use as exfoliant
Enow
what must a positive strand of an RNA virus do first
Kelsi-Ann Reply
A positive-sense single-stranded RNA virus (or (+)ssRNA virus) is a virus that uses positive sense single stranded RNA as its genetic material. Single stranded RNA viruses are classified as positive or negative depending on the sense or polarity of the RNA.
Dejene
 The positive-sense viral RNA genome can serve as messenger RNA and can be translated into protein in the host cell. Positive-sense ssRNA viruses belong to Group IV in the Baltimore classification. Positive-sense RNA viruses account for a large fraction of known viruses, including many pathogens
Dejene
such as the hepaci virus C, West nail virus, dengue virus, SARS and MERS coronaviruses, and SARS-CoV-2 as well as less clinically serious pathogens such as the rhinoviruses that cause the common cold.
Dejene
Why strong acid and alkline are not harmful to mycobacterium bacili?
Brian
What are the types of bacteria
John Reply
Do you mean the shapes or the the two different types of bacteria? Bacteria are often described in terms of their general shape. Common shapes include spherical (coccus), rod-shaped (bacillus), or curved (spirillum, spirochete, or vibrio) The two different types are gram negative or gram positive.
Melanie
what other characteristics of prokaryotes a bacteria don't have?
Brian
Prokaryotes are single-celled organisms belonging to the domains Bacteria and Archaea. Prokaryotic cells are much smaller than eukaryotic cells, have no nucelus, and lack organelles. All prokaryotic cells are encased by a cell wall. Many also have a capsule or slime layer made of polysaccharide.
Dejene
gram positive bacteria and gram negative bacteria
mubeen
Most bacteria can be broadly classified as Gram positive or Gram negative. Gram positive bacteria have cell walls composed of thick layers of peptidoglycan.cells stain purple when subjected to a Gram stain procedure. Gram negative bacteria have cell walls with a thin layer of peptidoglycan.
Dejene
all of you are amazing microbiologists
demisew
thanks demisew....
Dejene
guys what are the two acids the skin produce
Caro
what are the bacteria's involved in the decaying of food
Enow Reply
Some pathogenic bacteria, such as Clostridium perfringens and Bacillus cereus, are capable of causing spoilage.
Dejene
Corona has a gray and black cell structure ....if yes explain..if no explain
Joshua Reply
multiple questions and answers in microbiology and bio chemistry
Lakshmi Reply
is the study of a bacteria and other organisms
isir
yes..this book is about bacteria & others organisms
Hasan
biochemistry is the branch of science that dealing of chemical compounds reactions and other processes
isir
have you any question?
Hasan
yess, Why scientists not search coronavirus vaccines in short time.
demisew
they are on
Monyditchol
what are the symptoms for tuberculosis
Chiamaka
Most people infected with the bacteria that cause tuberculosis don't have symptoms. When symptoms do occur, they usually include a cough (sometimes blood-tinged), weight loss, night sweats and fever.
Dejene
symptoms tuberculosis. Fever Chills Night sweats Cough Loss of appetite Weight loss Blood in the sputum (phlegm) Loss of energy
lourdes
can corona virus transmitted from mother to her child through placenta ?
Abdul
probably
Mad
no
Oke
no,but it can through trait
Falere
mutation occur in the genome of corona virus. thats why the corona vaccines forming just difficult
Muzamil
intersted
Do
no
Esther
No
John
Yes
Suhaib
yes
Benjamin
yes coz it's spread through the soft body parts more so the openings in our bodies
Rebecca
Yes
Ayan
what is relation between fear (from covid 19 ) and immune sys ?
Abdul
because it damages the immune system by reduction the action of WBC
mike
reducing pls
mike
how is it possible for a woman to be pregnant and still See's her period
Prince Reply
we term it as discharge
Monyditchol
what is immunity
evans Reply
What is a varuis
evans
A submicroscopic infectious organism, now understood to be a non-cellular structure consisting of a core of DNA or RNA surrounded by a protein coat. It requires a living cell to replicate, and often causes disease
Ebo
A virus is a biological agent that reproduces inside the cells of living hosts. When infected by a virus, a host cell is forced to produce thousands of identical copies of the original virus at an extraordinary rate
Dejene
A virus is a microorganism which invade our bodies causing diseases due to eliciting immune responses by the body against it, can replicate using our genome inducing production of proteins helping them to establish new life inside our bodies.
What are the important of capsules
Marriam Reply
what are the roles of male sex hormones
Marriam
Testosterone is the principal sex hormone inmales and is produced in the testes (testicles). Dihydrotestosterone is a hormonein which the double bond of testosterone has been reduced by enzyrne reactions in the body. ... The testes perform two functions: They produce sperm, and they producetestoster
Dejene
Capsules in bacteria protect them from phagocytosis of eukaryotic organisms. This is what makes them virulent and harmful without antibodies.
Lewis
any one told me definition of amoebic dysentery & amoebic liver dysentery?
Mira
Amoebiasis, also known amoebic dysentery, is an infection caused by any of the amobae of the Entamoeba group. Symptoms are most common during infection by Entamoeba histolytica. Amoebiasis can be present with no, mild, or severe symptoms. Symptoms may include abdominal pain, diarrhea....
Dejene
tnx
Mira
u welcome mira
Dejene
people explain for me this words in public health.tb prevention 1:promotive 2:preventive 3:curative 4:rehabilitative
Obrian
Capsules function similarly to endospores they provide an extra layer of protection especially in acidic or basic environments. It is also a thicker membrane which can change the osmosis process and can provides resistance to antibotics depending if it is gram negative or positive.
Melanie
...As some antibotics focus on breaking down the cell wall and is not able to.
Melanie
what are the clinical classification of amoxicillin?
Rebecca
how does a autoimmune diso ders develop
Oliver Reply
simply autoimmune disease is not completely understood. There are many variations from genetically inherited to acquired by viruses like HIV. Genetically they may not be prominent until an unknown point in one's life. I am far from an expert, I am just reciting what I have learned. Take rheumatoid
Lewis
what is anatomy
Mohamed Reply
Anatomy is the study of parts of the human body
Matilda
the branch of science concerned with the bodily structure of humans, animals, and other living organisms, especially as revealed by dissection and the separation of parts.
Dejene
Describe the halden effect
Suleiman
The Haldane effect is a property of haemoglobin first described by John ScottHaldane. Oxygenation of blood in the lungs displaces carbon dioxide from hemoglobin which increases the removal of carbon dioxide. This property is the Haldane effect.
Dejene
Difference between chief cells and parietal cells in the stomach
Suleiman
 Parietal cells are the epithelialcells that secrete HCl and intrinsic factor. They are located in the gastric glands found in lining of fundus and stomach. The gastric chief cells , are cells in the stomach that release pepsinogen and chymosin.
Dejene
is the study of structure and organs located in human life
isir
listen to Matilda
Lewis
essay on microbiology and how it contribute to the pharmacy assistant programme
Tagedevi Reply
I want to know how it contribute to the pharmacy assistant programme
chidiebube
Contribute how? If you want to contribute to pharmaceutical stuff you should look for websites with blogs that relate to your interests.
Lewis
hello i want to know how it contribute to microbiology programs
Dejene
Microbiology is the study of bacteria and and organisms such as viruses, fungi, and mold. How does this apply to medicine? It applies to medicine or pharmacology because when you get sick you are infected by a pathogen and understanding how these organisms interact with each other helps you to....
Melanie
develop medicine. A lot of bacteria infections can be cured with various medicines but not all medicines work equally. It depends if your sickness is based on gram positve or negative bacteria, if its s mold or fungus or a virius. Each medicine targets a certain one.
Melanie
If you need any ideas I recommend looking up Louis Pastar who used microbiology to invent a lot of medicines and contributed greatly to microbiology and pharmaceutical.
Melanie
what is a bacterial
Eric Reply
Bacteria is a microscopic organism belonging to the kingdom prokaryotic
John
what is prokaryotic
Oliver
if you are here, read this free book, it is mostly correct, there are a few pictures that should be corrected
Lewis
thanks
Eric
A prokaryotes does not have lipid- bilayer bound organelles, they can reproduce by binary fission, they have a DNA region, most have a cell well, contains a plasmid, 70s ribosomes, high mutation rate due lack of certain DNA replication enzymes.
Eric
HIV And Coronavírus, what is the difference ? Both are Retrovirus, please , I want to know. Thank you.
Cl Reply
does it mean Corona is incurable just like the HIV for the it to be retroviral too?
Joy
The reason researchers are looking to these medicines is that the new coronavirus—like HIV, Ebola, and hepatitis C—are all RNA viruses.but covid-19 is to detect human and animal virus. hiv is only human virus do not detecte animals
Dejene
***niaid.nih.gov/diseases-conditions/coronaviruses start here, since this is what is new, then recap yourself on autoimmune diseases that are not recoverable
Lewis
what happen when virus escape the host
Hailemichael
A virus must attach to a living cell, be taken inside, manufacture its proteins and copy its genome, and find a way to escape the cell so that the virus can infect other cells. Viruses can infect only certain species of hosts and only certain cells within that host.
Dejene
what is the difference between capsule and glycocylx in relation to prokaryotes
Felix Reply
However glycocalyx exists in bacteria as either a capsule or a slime layer. Thedifference between a capsule and a slime layer is that in a capsule polysaccharides are firmly attached to the cell wall, while in aslime layer, the glycoproteins are loosely attached to the cell wall.
Dejene
Glycocalyx is composed of glycosaminoglycans, proteoglycans and other glycoproteins bearing acidic oligosaccharides and terminal sialic acids. Capsule is Composed of polysaccharide (i.e. poly: many, saccharide: sugar). Exception: The capsule of Bacillus anthracis is composed of polymerized D-glutami
assarra
Capsule is located immediately exterior to the murein (peptidoglycan) layer  of gram-positive bacteria and the outer membrane (Lipopolysaccharide layer) of gram-negative bacteria The glycocalyx, which is located on the apical surface of endothelial cells, is composed of a negatively charged network
assarra
Meu I watch at microscopic HIV
Cl
assarra is paying attention. look into taking a course is you want to truly understand what is known now
Lewis

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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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