central dogma of genetic information and DNA replication

ANDREA CAROLINA VARGAS OLMOS MEDICINE ESTUDENT

RNA is created from a DNA molecule, the difference is that the RNA consists of a single

chain that containing the codons (sequence of 3 nucleotides) that give rise to the different

amino-acids.

the transport of mRNA is critical in protein synthesis.

the replication occurs in coordination with cell division, and requires several

enzymes such as helicase whose function is the separating two annealed nucleic acid strands .

SCIENTIST CONTRUCT VISUAL OF INTRACELLULAR “ZIP CODE” SIGNALING LINKED

TO LEARNINGMEMORY. July 15, 2013. science daily

after a long process of investigations a graduate student of the university of Vermont obtained visual evidence of the mechanisms involved when a cell transports mRNA (or messenger RNA) to where a protein is needed to perform a cellular function.

mRNA is an important molecule in the process of protein synthesis. the process of mRNA localization is critical for cellular function, for these Thomas Sladewsky proposed the existence of a "zip code" to ensure the transport of this molecule to the translation places into the cell(ribosomes).

these zip codes help transport the mRNA by linking up with a tiny molecular motor called myosin, which walks on a track called actin, carrying the mRNA to its destination

for each RNA molecules, exist a lot of zip codes to ensure that the mRNA will engage with at least one motor and will be successfully transported to its destination.

the synaptic plasticity is essential to the

learning process and memory.

defects in synaptic plasticity (neuronal communication) are

related to defects in the mRNA transport.

Personal opiniónin my opinion this research realized by Thomas Sladewsky gives

us important insights into the complex process of protein synthesis from macromolecules such as DNA and RNA. for me

the discovery of this signal, responsible for the transport of mRNA can lead to a great improvement over the treatment and understanding of some diseases associated with defects in the

long process of protein synthesis.

KEY STEP IN MOLECULAR 'DANCE' THAT DUPLICATES DNA DECIPHERED. July

14,2012. science daily

this investigation is aimed at understanding the molecular details

and mechanism of DNA replication at a fundamental level, based in the

relation between the "origin recognition complex" (ORC) and the

helicase.

the mounting in the laboratory included freezing and purification processes, with the objective of arrest the process during the assembly of the helicase, finally they took tens of thousands of pictures with a cry-electron microscope.

Thanks to this, an important information was obtained about the disposition of the helicase and ORC in the process of cell replication.

Binding of the helicase core components appears to shift the ORC into a spiral conformation that closely matches the spiral shape of double-stranded DNA.This shape-shifting of the ORC appears to be an important step in facilitating binding of the ring-shaped helicase to the DNA

in my opinion this research brings us closer to a better understanding and discovery of potential treatments for

diseases associated with mutations in the genetic material, by defects in the DNA

replication process.

Personal opinión

today thanks to the great advances in technology, we

managed have a great knowledge about the structure

of DNA and all the processes arising from this

macromolecule (replication, transcription), the scientists have identified a number

mutations in the genes which give rise to a disease. so any

study that have the objective to study the different processes and transformations of the genetic information, have

medical utility.

diseases like Alzheimer's and spinal muscular atrophy are related to defects in the transport of m-RNA to ribosomes. the discovery of zip code signal involved in the transport of m-RNA could provide potential treatments for these diseases.

defects in the transport of RNA are also associated with

synaptic plasticity damage affecting memory and learning.

on the other hand, damages in the replication process may lead to mutations in the DNA molecule and the appearance of different diseases, including cancer. is important to have good knowledge of all the processes involved in replication, for have a possible of created a new form to fight cancer

REFERENCES

•Journal reference: Thomas E Sladewski, Carol S Bookwalter, Myoung-Soon Hong, Kathleen M Trybus. Single-molecule reconstitution of mRNA transport by a class V myosin. Nature Structural & Molecular Biology, 2013; DOI: 10.1038/nsmb.2614•Journal reference: Jingchuan Sun, Cecile Evrin, Stefan A Samel, Alejandra Fernández-Cid, Alberto Riera, Hironori Kawakami, Bruce Stillman, Christian Speck, Huilin Li. Cryo-EM structure of a helicase loading intermediate containing ORC–Cdc6–Cdt1–MCM2-7 bound to DNA. Nature Structural & Molecular Biology, 2013; DOI: 10.1038/nsmb.2629•MARTINEZ SÁNCHEZ, Lina María. Biología molecular. 7.ed. Medellin:UPB.fac.de medicina,2012. 292p.