Faulty Membrane Repair May Lead To Muscular Dystrophy

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Faulty Membrane Repair May Lead To Muscular
Dystrophy

• a new pathway for the
  genesis of muscular dystrophy

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Dystrophin the key protein in Duchenne muscular
dystrophy
Defects in the dystrophin gene render the muscle
cell wall weaker and more susceptible to collapse
in Duchenne's patients, and it was believed that
structural defects in the cell membrane might be
responsible for the other muscular dystrophies
The key protein in DMD
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A new proteinDysfelin
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• When the body is hurt, the injured muscle cell is
  stimulated to collect the Ca2 which cause the
  levels rising of Ca2. The high level of Ca2
  will make a signal which stimulates the muscle
  cells to secrete a lot of vesicles. When the
  vesicles accumulate to a certain number, cells
  that remain around the wound can be fused with
  each other, especially with the erythrocyte, so
  that the wound can be covered by a pile of fused
  cells, as a result, the muscle cells can be
  protected from further damages.

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• There are many important factors in this
  repairing work. Some of them are belong to the
  protein familys SNARE and SNAP. This two kinds of
  proteins also play important roles in the
  vesicle-fusion of the nerve conduction.
• One of this kind of protein has two special
  domain that can adhere to the plasma membrane,
  this process depends on the Ca2 . That make this
  protein to be a appropriate Ca2 sensor.

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• Dysferlin was found in the sarcolemma and
  vesicles. It now appears that the muscular
  dystrophies can arrive at their muscle-whittling
  goal by another route. A genetic mutation found
  in people with either of two forms of the
  disease, limb girdle muscular dystrophy type 2B
  and Miyoshi myopathy, appears to cause disease by
  impeding the muscle cell's efforts to fix the
  everyday wear and tear that even healthy
  membranes experience.

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• Lack of dysferlin lead to neither the disfunction
  of the dystrofin-associated glycoprotein complex
  nor the lose of stabilization in the sarcolemma.
  That is to say, the function of dysferlin has
  nothing to do with the dystrofin-associated
  glycoprotein.
• Actually, the scientist found that dysferlin
  functions in the Ca 2 related repair of
  membrane.

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• Muscular dystrophy may result when muscle cells
  lose their ability to repair everyday wear and
  tear on their membranes. Normally, when a cell
  membrane is damaged, intracellular vesicles
  travel to the site of injury where they form a
  kind of protective patch. Dysferlin, which binds
  the annexins, may help guide the vesicle patch to
  the site of injury. Defects in dysferlin, which
  have been found in people with some forms of
  muscular dystrophy, could therefore lead to
  disease by preventing injury repair.

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