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Chaperones are
proteins in the cell which function to
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help proteins to
fold correctly
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molecular
chaparones guide folding of proteins present in the
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cytosol, lumen of
RER, mitochondria, etc.
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chaparones also
promote the assembly of protein complexes from
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subunits
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chaperones
prevent the aggregation of unfolded proteins
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heat shock
proteins
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a set of
proteins induced by a brief exposure of cells to elevated
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temperature (42°
C)
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many of
molecular chaperones are heat shock proteins (hsp)
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the heat shock
causes many proteins to unfold or misfold and the
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hsp are induced
to help refold these proteins correctly
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examples of heat
shock proteins:
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hsp 70 -
cytosol hsp 60 - cytosol BiP - in lumen of RER (BiP is
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an
abbreviation for
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binding
protein) mitochondrial hsp - (mhsp 60 and mhsp 70)
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mechanism of
action:
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bind to exposed hydrophobic regions of
proteins to achieve
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proper folding
ATP requirement for action
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