Association of the chaperone alphaB-crystallin with titin in heart muscle.
alphaB-crystallin, a major component of the vertebrate lens, is a chaperone belonging to the family of small heat shock proteins. These proteins form oligomers that bind to partially unfolded substrates and prevent denaturation. alphaB-crystallin in cardiac muscle binds to myofibrils under condition...
| 主要な著者: | , , , , , , , , , , |
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| フォーマット: | Journal article |
| 言語: | English |
| 出版事項: |
2004
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| _version_ | 1826266942956109824 |
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| author | Bullard, B Ferguson, C Minajeva, A Leake, M Gautel, M Labeit, D Ding, L Labeit, S Horwitz, J Leonard, K Linke, W |
| author_facet | Bullard, B Ferguson, C Minajeva, A Leake, M Gautel, M Labeit, D Ding, L Labeit, S Horwitz, J Leonard, K Linke, W |
| author_sort | Bullard, B |
| collection | OXFORD |
| description | alphaB-crystallin, a major component of the vertebrate lens, is a chaperone belonging to the family of small heat shock proteins. These proteins form oligomers that bind to partially unfolded substrates and prevent denaturation. alphaB-crystallin in cardiac muscle binds to myofibrils under conditions of ischemia, and previous work has shown that the protein binds to titin in the I-band of cardiac fibers (Golenhofen, N., Arbeiter, A., Koob, R., and Drenckhahn, D. (2002) J. Mol. Cell. Cardiol. 34, 309-319). This part of titin extends as muscles are stretched and is made up of immunoglobulin-like modules and two extensible regions (N2B and PEVK) that have no well defined secondary structure. We have followed the position of alphaB-crystallin in stretched cardiac fibers relative to a known part of the titin sequence. alphaB-crystallin bound to a discrete region of the I-band that moved away from the Z-disc as sarcomeres were extended. In the physiological range of sarcomere lengths, alphaB-crystallin bound in the position of the N2B region of titin, but not to PEVK. In overstretched myofibrils, it was also in the Ig region between N2B and the Z-disc. Binding between alphaB-crystallin and N2B was confirmed using recombinant titin fragments. The Ig domains in an eight-domain fragment were stabilized by alphaB-crystallin; atomic force microscopy showed that higher stretching forces were needed to unfold the domains in the presence of the chaperone. Reversible association with alphaB-crystallin would protect I-band titin from stress liable to cause domain unfolding until conditions are favorable for refolding to the native state. |
| first_indexed | 2024-03-06T20:46:37Z |
| format | Journal article |
| id | oxford-uuid:361f5f3c-4091-4f1b-a504-cedd7ac75ee1 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:46:37Z |
| publishDate | 2004 |
| record_format | dspace |
| spelling | oxford-uuid:361f5f3c-4091-4f1b-a504-cedd7ac75ee12022-03-26T13:35:56ZAssociation of the chaperone alphaB-crystallin with titin in heart muscle.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:361f5f3c-4091-4f1b-a504-cedd7ac75ee1EnglishSymplectic Elements at Oxford2004Bullard, BFerguson, CMinajeva, ALeake, MGautel, MLabeit, DDing, LLabeit, SHorwitz, JLeonard, KLinke, WalphaB-crystallin, a major component of the vertebrate lens, is a chaperone belonging to the family of small heat shock proteins. These proteins form oligomers that bind to partially unfolded substrates and prevent denaturation. alphaB-crystallin in cardiac muscle binds to myofibrils under conditions of ischemia, and previous work has shown that the protein binds to titin in the I-band of cardiac fibers (Golenhofen, N., Arbeiter, A., Koob, R., and Drenckhahn, D. (2002) J. Mol. Cell. Cardiol. 34, 309-319). This part of titin extends as muscles are stretched and is made up of immunoglobulin-like modules and two extensible regions (N2B and PEVK) that have no well defined secondary structure. We have followed the position of alphaB-crystallin in stretched cardiac fibers relative to a known part of the titin sequence. alphaB-crystallin bound to a discrete region of the I-band that moved away from the Z-disc as sarcomeres were extended. In the physiological range of sarcomere lengths, alphaB-crystallin bound in the position of the N2B region of titin, but not to PEVK. In overstretched myofibrils, it was also in the Ig region between N2B and the Z-disc. Binding between alphaB-crystallin and N2B was confirmed using recombinant titin fragments. The Ig domains in an eight-domain fragment were stabilized by alphaB-crystallin; atomic force microscopy showed that higher stretching forces were needed to unfold the domains in the presence of the chaperone. Reversible association with alphaB-crystallin would protect I-band titin from stress liable to cause domain unfolding until conditions are favorable for refolding to the native state. |
| spellingShingle | Bullard, B Ferguson, C Minajeva, A Leake, M Gautel, M Labeit, D Ding, L Labeit, S Horwitz, J Leonard, K Linke, W Association of the chaperone alphaB-crystallin with titin in heart muscle. |
| title | Association of the chaperone alphaB-crystallin with titin in heart muscle. |
| title_full | Association of the chaperone alphaB-crystallin with titin in heart muscle. |
| title_fullStr | Association of the chaperone alphaB-crystallin with titin in heart muscle. |
| title_full_unstemmed | Association of the chaperone alphaB-crystallin with titin in heart muscle. |
| title_short | Association of the chaperone alphaB-crystallin with titin in heart muscle. |
| title_sort | association of the chaperone alphab crystallin with titin in heart muscle |
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