Cargando…
Chaperonin-mediated folding of vertebrate actin-related protein and gamma-tubulin
The folding of actin and tubulin is mediated via interaction with a heteromeric toroidal complex (cytoplasmic chaperonin) that hydrolyzes ATP as part of the reaction whereby native proteins are ultimately released. Vertebrate actin-related protein (actin-RPV) (also termed centractin) and gamma-tubul...
Formato: | Texto |
---|---|
Lenguaje: | English |
Publicado: |
The Rockefeller University Press
1993
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2119862/ https://www.ncbi.nlm.nih.gov/pubmed/8104191 |
_version_ | 1782141359782625280 |
---|---|
collection | PubMed |
description | The folding of actin and tubulin is mediated via interaction with a heteromeric toroidal complex (cytoplasmic chaperonin) that hydrolyzes ATP as part of the reaction whereby native proteins are ultimately released. Vertebrate actin-related protein (actin-RPV) (also termed centractin) and gamma-tubulin are two proteins that are distantly related to actin and tubulin, respectively: gamma-tubulin is exclusively located at the centrosome, while actin-RPV is conspicuously abundant at the same site. Here we show that actin-RPV and gamma- tubulin are both folded via interaction with the same chaperonin that mediates the folding of beta-actin and alpha- and beta-tubulin. In each case, the unfolded polypeptide forms a binary complex with cytoplasmic chaperonin and is released as a soluble, monomeric protein in the presence of Mg-ATP and the presence or absence of Mg-GTP. In contrast to alpha- and beta-tubulin, the folding of gamma-tubulin does not require the presence of cofactors in addition to chaperonin itself. Monomeric actin-RPV produced in in vitro folding reactions cocycles efficiently with native brain actin, while in vitro folded gamma- tubulin binds to polymerized microtubules in a manner consistent with interaction with microtubule ends. Both monomeric actin-RPV and gamma- tubulin bind to columns of immobilized nucleotide: monomeric actin-RPV has no marked preference for ATP or GTP, while gamma-tubulin shows some preference for GTP binding. We show that actin-RPV and gamma-tubulin compete with one another, and with beta-actin or alpha-tubulin, for binary complex formation with cytoplasmic chaperonin. |
format | Text |
id | pubmed-2119862 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1993 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21198622008-05-01 Chaperonin-mediated folding of vertebrate actin-related protein and gamma-tubulin J Cell Biol Articles The folding of actin and tubulin is mediated via interaction with a heteromeric toroidal complex (cytoplasmic chaperonin) that hydrolyzes ATP as part of the reaction whereby native proteins are ultimately released. Vertebrate actin-related protein (actin-RPV) (also termed centractin) and gamma-tubulin are two proteins that are distantly related to actin and tubulin, respectively: gamma-tubulin is exclusively located at the centrosome, while actin-RPV is conspicuously abundant at the same site. Here we show that actin-RPV and gamma- tubulin are both folded via interaction with the same chaperonin that mediates the folding of beta-actin and alpha- and beta-tubulin. In each case, the unfolded polypeptide forms a binary complex with cytoplasmic chaperonin and is released as a soluble, monomeric protein in the presence of Mg-ATP and the presence or absence of Mg-GTP. In contrast to alpha- and beta-tubulin, the folding of gamma-tubulin does not require the presence of cofactors in addition to chaperonin itself. Monomeric actin-RPV produced in in vitro folding reactions cocycles efficiently with native brain actin, while in vitro folded gamma- tubulin binds to polymerized microtubules in a manner consistent with interaction with microtubule ends. Both monomeric actin-RPV and gamma- tubulin bind to columns of immobilized nucleotide: monomeric actin-RPV has no marked preference for ATP or GTP, while gamma-tubulin shows some preference for GTP binding. We show that actin-RPV and gamma-tubulin compete with one another, and with beta-actin or alpha-tubulin, for binary complex formation with cytoplasmic chaperonin. The Rockefeller University Press 1993-09-02 /pmc/articles/PMC2119862/ /pubmed/8104191 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 Chaperonin-mediated folding of vertebrate actin-related protein and gamma-tubulin |
title | Chaperonin-mediated folding of vertebrate actin-related protein and gamma-tubulin |
title_full | Chaperonin-mediated folding of vertebrate actin-related protein and gamma-tubulin |
title_fullStr | Chaperonin-mediated folding of vertebrate actin-related protein and gamma-tubulin |
title_full_unstemmed | Chaperonin-mediated folding of vertebrate actin-related protein and gamma-tubulin |
title_short | Chaperonin-mediated folding of vertebrate actin-related protein and gamma-tubulin |
title_sort | chaperonin-mediated folding of vertebrate actin-related protein and gamma-tubulin |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2119862/ https://www.ncbi.nlm.nih.gov/pubmed/8104191 |