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Axonal transport of calmodulin: a physiologic approach to identification of long-term associations between proteins
Calmodulin is a soluble, heat-stable protein which has been shown to modulate both membrane-bound and soluble enzymes, but relatively little has been known about the in vivo associations of calmodulin. A 17,000- dalton heat-stable protein was found to move in axonal transport in the guinea pig visua...
Formato: | Texto |
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Lenguaje: | English |
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The Rockefeller University Press
1981
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2111803/ https://www.ncbi.nlm.nih.gov/pubmed/6166619 |
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collection | PubMed |
description | Calmodulin is a soluble, heat-stable protein which has been shown to modulate both membrane-bound and soluble enzymes, but relatively little has been known about the in vivo associations of calmodulin. A 17,000- dalton heat-stable protein was found to move in axonal transport in the guinea pig visual system with the proteins of slow component b (SCb; 2 mm/d) along with actin and the bulk of the soluble proteins of the axon. Co-electrophoresis of purified calmodulin and radioactively labeled SCb proteins in two dimensional polyacrylamide gel electrophoresis (PAGE) demonstrated the identity of the heat-stable SCb protein and calmodulin on the basis of pI, molecular weight, and anomalous migration in the presence of Ca2+-chelating agents. No proteins co-migrating with calmodulin in two-dimensional PAGE could be detected among the proteins of slow component a (SCa; 0.3 mm/d, microtubules and neurofilaments) or fast component (FC; 250 mm/d, membrane-associated proteins). We conclude that calmodulin is transported solely as part of the SCb complex of proteins, the axoplasmic matrix. Calmodulin moves in axonal transport independent of the movements of microtubules (SCa) and membranes (FC), which suggests that the interactions of calmodulin with these structures may represent a transient interaction between groups of proteins moving in axonal transport at different rates. Axonal transport has been shown to be an effective tool for the demonstration of long-term in vivo protein associations. |
format | Text |
id | pubmed-2111803 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1981 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21118032008-05-01 Axonal transport of calmodulin: a physiologic approach to identification of long-term associations between proteins J Cell Biol Articles Calmodulin is a soluble, heat-stable protein which has been shown to modulate both membrane-bound and soluble enzymes, but relatively little has been known about the in vivo associations of calmodulin. A 17,000- dalton heat-stable protein was found to move in axonal transport in the guinea pig visual system with the proteins of slow component b (SCb; 2 mm/d) along with actin and the bulk of the soluble proteins of the axon. Co-electrophoresis of purified calmodulin and radioactively labeled SCb proteins in two dimensional polyacrylamide gel electrophoresis (PAGE) demonstrated the identity of the heat-stable SCb protein and calmodulin on the basis of pI, molecular weight, and anomalous migration in the presence of Ca2+-chelating agents. No proteins co-migrating with calmodulin in two-dimensional PAGE could be detected among the proteins of slow component a (SCa; 0.3 mm/d, microtubules and neurofilaments) or fast component (FC; 250 mm/d, membrane-associated proteins). We conclude that calmodulin is transported solely as part of the SCb complex of proteins, the axoplasmic matrix. Calmodulin moves in axonal transport independent of the movements of microtubules (SCa) and membranes (FC), which suggests that the interactions of calmodulin with these structures may represent a transient interaction between groups of proteins moving in axonal transport at different rates. Axonal transport has been shown to be an effective tool for the demonstration of long-term in vivo protein associations. The Rockefeller University Press 1981-06-01 /pmc/articles/PMC2111803/ /pubmed/6166619 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Articles Axonal transport of calmodulin: a physiologic approach to identification of long-term associations between proteins |
title | Axonal transport of calmodulin: a physiologic approach to identification of long-term associations between proteins |
title_full | Axonal transport of calmodulin: a physiologic approach to identification of long-term associations between proteins |
title_fullStr | Axonal transport of calmodulin: a physiologic approach to identification of long-term associations between proteins |
title_full_unstemmed | Axonal transport of calmodulin: a physiologic approach to identification of long-term associations between proteins |
title_short | Axonal transport of calmodulin: a physiologic approach to identification of long-term associations between proteins |
title_sort | axonal transport of calmodulin: a physiologic approach to identification of long-term associations between proteins |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2111803/ https://www.ncbi.nlm.nih.gov/pubmed/6166619 |