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Unc-45 Mutations in Caenorhabditis elegans Implicate a CRO1/She4p-like Domain in Myosin Assembly
The Caenorhabditis elegans unc-45 locus has been proposed to encode a protein machine for myosin assembly. The UNC-45 protein is predicted to contain an NH(2)-terminal domain with three tetratricopeptide repeat motifs, a unique central region, and a COOH-terminal domain homologous to CRO1 and She4p....
Autores principales: | , , , |
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
The Rockefeller University Press
1998
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2133068/ https://www.ncbi.nlm.nih.gov/pubmed/9832550 |
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author | Barral, José M. Bauer, Christopher C. Ortiz, Irving Epstein, Henry F. |
author_facet | Barral, José M. Bauer, Christopher C. Ortiz, Irving Epstein, Henry F. |
author_sort | Barral, José M. |
collection | PubMed |
description | The Caenorhabditis elegans unc-45 locus has been proposed to encode a protein machine for myosin assembly. The UNC-45 protein is predicted to contain an NH(2)-terminal domain with three tetratricopeptide repeat motifs, a unique central region, and a COOH-terminal domain homologous to CRO1 and She4p. CRO1 and She4p are fungal proteins required for the segregation of other molecules in budding, endocytosis, and septation. Three mutations that lead to temperature-sensitive (ts) alleles have been localized to conserved residues within the CRO1/She4p-like domain, and two lethal alleles were found to result from stop codon mutations in the central region that would prevent translation of the COOH-terminal domain. Electron microscopy shows that thick filament accumulation in vivo is decreased by ∼50% in the CB286 ts mutant grown at the restrictive temperature. The thick filaments that assemble have abnormal structure. Immunofluorescence and immunoelectron microscopy show that myosins A and B are scrambled, in contrast to their assembly into distinct regions at the permissive temperature and in wild type. This abnormal structure correlates with the high degree of instability of the filaments in vitro as reflected by their extremely low yields and shortened lengths upon isolation. These results implicate the UNC-45 CRO1/She4p-like region in the assembly of myosin isoforms in C. elegans and suggest a possible common mechanism for the function of this UCS (UNC-45/CRO1/She4p) protein family. |
format | Text |
id | pubmed-2133068 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1998 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21330682008-05-01 Unc-45 Mutations in Caenorhabditis elegans Implicate a CRO1/She4p-like Domain in Myosin Assembly Barral, José M. Bauer, Christopher C. Ortiz, Irving Epstein, Henry F. J Cell Biol Article The Caenorhabditis elegans unc-45 locus has been proposed to encode a protein machine for myosin assembly. The UNC-45 protein is predicted to contain an NH(2)-terminal domain with three tetratricopeptide repeat motifs, a unique central region, and a COOH-terminal domain homologous to CRO1 and She4p. CRO1 and She4p are fungal proteins required for the segregation of other molecules in budding, endocytosis, and septation. Three mutations that lead to temperature-sensitive (ts) alleles have been localized to conserved residues within the CRO1/She4p-like domain, and two lethal alleles were found to result from stop codon mutations in the central region that would prevent translation of the COOH-terminal domain. Electron microscopy shows that thick filament accumulation in vivo is decreased by ∼50% in the CB286 ts mutant grown at the restrictive temperature. The thick filaments that assemble have abnormal structure. Immunofluorescence and immunoelectron microscopy show that myosins A and B are scrambled, in contrast to their assembly into distinct regions at the permissive temperature and in wild type. This abnormal structure correlates with the high degree of instability of the filaments in vitro as reflected by their extremely low yields and shortened lengths upon isolation. These results implicate the UNC-45 CRO1/She4p-like region in the assembly of myosin isoforms in C. elegans and suggest a possible common mechanism for the function of this UCS (UNC-45/CRO1/She4p) protein family. The Rockefeller University Press 1998-11-30 /pmc/articles/PMC2133068/ /pubmed/9832550 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 | Article Barral, José M. Bauer, Christopher C. Ortiz, Irving Epstein, Henry F. Unc-45 Mutations in Caenorhabditis elegans Implicate a CRO1/She4p-like Domain in Myosin Assembly |
title |
Unc-45 Mutations in Caenorhabditis elegans Implicate a CRO1/She4p-like Domain in Myosin Assembly |
title_full |
Unc-45 Mutations in Caenorhabditis elegans Implicate a CRO1/She4p-like Domain in Myosin Assembly |
title_fullStr |
Unc-45 Mutations in Caenorhabditis elegans Implicate a CRO1/She4p-like Domain in Myosin Assembly |
title_full_unstemmed |
Unc-45 Mutations in Caenorhabditis elegans Implicate a CRO1/She4p-like Domain in Myosin Assembly |
title_short |
Unc-45 Mutations in Caenorhabditis elegans Implicate a CRO1/She4p-like Domain in Myosin Assembly |
title_sort | unc-45 mutations in caenorhabditis elegans implicate a cro1/she4p-like domain in myosin assembly |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2133068/ https://www.ncbi.nlm.nih.gov/pubmed/9832550 |
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