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wasin kusakabe

Direct transfer of plant genes from chloroplasts into the cell nucleus: Gene function p... - 0 views

www.sciencedaily.com/...120413121916.htm

Genes Chloroplasts Cell Nucleus DNA

shared by wasin kusakabe on 14 Apr 12 - No Cached
  • Chloroplasts, the plant cell's green solar power generators, were once living beings in their own right.
  • This changed about one billion years ago, when they were swallowed up but not digested by larger cells.
  • either direct transport in the form of DNA fragments from the chloroplasts to the nucleus or transport in the form of mRNA, which is then transcribed back into DNA.
  • ...5 more annotations...
  • Genes consist of several modules, separated by non-coding DNA regions (introns).
  • It was found that the transfer takes place without the involvement of RNA and that the DNA apparently jumps directly from the cell's chloroplasts into its nucleus.
  • t is thought that the introns even help the splicing enzymes by folding themselves into stable RNA structures, thus directing the enzymes to the right locations.
  • Since the introns obstruct protein synthesis, they need to be removed from the mRNA, a procedure described as splicing.
    • wasin kusakabe
      wasin kusakabe on 14 Apr 12
       
      The Chloroplasts was an different entity before they were swallowed up by larger cells to corporate with each other.
  • wasin kusakabe on 14 Apr 12
     
    The differences between the genes in the chloroplasts and the genes in the nucleus being researched.
Nitchakan Chaiprukmalakan

Biotechdaily - Human Mitochondrial Mutations Repaired by New Technique - 2 views

www.biotechdaily.com/...repaired_by_new_technique.html

shared by Nitchakan Chaiprukmalakan on 01 Apr 12 - No Cached
  • researchers have identified a generic approach to correct mutations in human mitochondrial DNA by targeting corrective RNAs,
  • In adults, many aging disorders have been associated with defects of mitochondrial function, including diabetes, Parkinson’s disease, cancer, heart disease, stroke, and Alzheimer’s disease.
  • The introduction of nucleus-encoded small RNAs into mitochondria is critical for the replication, transcription, and translation of the mitochondrial genome,
  • ...4 more annotations...
  • The study defined a new role for a protein called polynucleotide phosphorylase (PNPASE) in regulating the import of RNA into mitochondria. Reducing the expression--or output--of PNPASE decreased RNA import, which impaired the processing of mitochondrial genome-encoded RNAs. Reduced RNA processing inhibited the translation of proteins required to maintain the mitochondrial electron transport chain that consumes oxygen during cell respiration to produce energy. With reduced PNPASE, unprocessed mitochondrial-encoded RNAs accumulated, protein translation was inhibited, and energy production was compromised, leading to stalled cell growth.
  • Geng Wang developed a strategy to target and import specific RNA molecules encoded in the nucleus into the mitochondria and, once there, to express proteins needed to repair mitochondrial gene mutations.
  • First, the researchers had to find a way to stabilize the reparative RNA so that it was moved out of the nucleus and then localized to the mitochondrial outer membrane. This was accomplished by modifying an export sequence to direct the RNA to the mitochondrion. Once the RNA was in the area of the transport machinery on the mitochondrial surface, then a second transport sequence was required to direct the RNA into the targeted organelle. With these two modifications, a wide range of RNAs were targeted to and imported into the mitochondria, where they worked to repair defects in mitochondrial respiration and energy production in two different cell line models of human mitochondrial disease.
    • Nitchakan Chaiprukmalakan
      Nitchakan Chaiprukmalakan on 03 Apr 12
       
      This article shows the importance of the RNAs in making proteins for the mitochondria to work efficiently.  The article summarizes a method in repairing the mitochondria that is still being worked on.
  • wasin kusakabe on 01 Apr 12
     
    Mutations in the mitochondrial genome inflicts diseases
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