The role of the C-terminal extension of αB-crystallin upon structure and function and the relationship with disease
The eye lens protein αB-crystallin plays an important role in maintaining the refractive index of the lens, however is also found in many non-lenticular tissues suggest that it has general cellular functions over and above its role in light refraction. The role of the C-terminal extension of αB -cry...
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ndltd-bl.uk-oai-ethos.bl.uk-4906482015-03-20T04:49:30ZThe role of the C-terminal extension of αB-crystallin upon structure and function and the relationship with diseaseHayes, Victoria. H.2008The eye lens protein αB-crystallin plays an important role in maintaining the refractive index of the lens, however is also found in many non-lenticular tissues suggest that it has general cellular functions over and above its role in light refraction. The role of the C-terminal extension of αB -cryStellin upon solubility, structure and function and the relationship with disease has not been investigated. In this study, the systematic analysis of the role of the C-terminal extension of αB -crystallin aimed to investigate the hypothesis that the C-terminal region in αB -crystallm is important for solubility, structure and function of the protein. This study also aimed to find a link between the role of the C-terminal and the symptoms of disease, thus providing a potential explanation of whether the three congenital mutations (450delA, Q151X and 464delCT), which alter the C-terminal extension of αB -crystallin, cause the various diseases via the loss of chaperone function or perhaps by a different mechanism. Further more this study aimed to elucidate the mechanism of phenotypic heterogeneity associated with these αB -crystallin mutations.I compared the three C-terminal αB -crystallin mutants (450delA, Q151X and 464delCT) to a series of C-terminal truncations (E164X, E165X, K174X and A171X) and found that the C-terminal extension was essential for oligomerisation but not chaperone function, infact the removal of the entire C-terminal extension actually enhanced chaperone activity, however significantly destabilized αB -crystallin causing it to self-aggregate. This instability was supported by refolding analysis, where the 450delA and 464delCT mutants could only be refolded and assayed as a complex with wild type αB -crystallin, however the Q151X αB -crystallin could be refolded alone. From these studies, I conclude that all three disease-causing mutations (450delA, 464delCT and Q151X) in the C-terminal extension destabilise αB -crystฝlin and increase its tendency to self-aggregate. I propose that it is this, rather than a catastrophic loss of chaperone activity, that is a major factor in disease development.572.8Durham Universityhttp://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490648http://etheses.dur.ac.uk/2929/Electronic Thesis or Dissertation |
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572.8 Hayes, Victoria. H. The role of the C-terminal extension of αB-crystallin upon structure and function and the relationship with disease |
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The eye lens protein αB-crystallin plays an important role in maintaining the refractive index of the lens, however is also found in many non-lenticular tissues suggest that it has general cellular functions over and above its role in light refraction. The role of the C-terminal extension of αB -cryStellin upon solubility, structure and function and the relationship with disease has not been investigated. In this study, the systematic analysis of the role of the C-terminal extension of αB -crystallin aimed to investigate the hypothesis that the C-terminal region in αB -crystallm is important for solubility, structure and function of the protein. This study also aimed to find a link between the role of the C-terminal and the symptoms of disease, thus providing a potential explanation of whether the three congenital mutations (450delA, Q151X and 464delCT), which alter the C-terminal extension of αB -crystallin, cause the various diseases via the loss of chaperone function or perhaps by a different mechanism. Further more this study aimed to elucidate the mechanism of phenotypic heterogeneity associated with these αB -crystallin mutations.I compared the three C-terminal αB -crystallin mutants (450delA, Q151X and 464delCT) to a series of C-terminal truncations (E164X, E165X, K174X and A171X) and found that the C-terminal extension was essential for oligomerisation but not chaperone function, infact the removal of the entire C-terminal extension actually enhanced chaperone activity, however significantly destabilized αB -crystallin causing it to self-aggregate. This instability was supported by refolding analysis, where the 450delA and 464delCT mutants could only be refolded and assayed as a complex with wild type αB -crystallin, however the Q151X αB -crystallin could be refolded alone. From these studies, I conclude that all three disease-causing mutations (450delA, 464delCT and Q151X) in the C-terminal extension destabilise αB -crystฝlin and increase its tendency to self-aggregate. I propose that it is this, rather than a catastrophic loss of chaperone activity, that is a major factor in disease development. |
author |
Hayes, Victoria. H. |
author_facet |
Hayes, Victoria. H. |
author_sort |
Hayes, Victoria. H. |
title |
The role of the C-terminal extension of αB-crystallin upon structure and function and the relationship with disease |
title_short |
The role of the C-terminal extension of αB-crystallin upon structure and function and the relationship with disease |
title_full |
The role of the C-terminal extension of αB-crystallin upon structure and function and the relationship with disease |
title_fullStr |
The role of the C-terminal extension of αB-crystallin upon structure and function and the relationship with disease |
title_full_unstemmed |
The role of the C-terminal extension of αB-crystallin upon structure and function and the relationship with disease |
title_sort |
role of the c-terminal extension of αb-crystallin upon structure and function and the relationship with disease |
publisher |
Durham University |
publishDate |
2008 |
url |
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490648 |
work_keys_str_mv |
AT hayesvictoriah theroleofthecterminalextensionofabcrystallinuponstructureandfunctionandtherelationshipwithdisease AT hayesvictoriah roleofthecterminalextensionofabcrystallinuponstructureandfunctionandtherelationshipwithdisease |
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1716786639734308864 |