The Caenorhabditis elegans polarity gene ooc-5 encodes a Torsin-related protein of the AAA ATPase superfamily.
The PAR proteins are required for polarity and asymmetric localization of cell fate determinants in C. elegans embryos. In addition, several of the PAR proteins are conserved and localized asymmetrically in polarized cells in Drosophila, Xenopus and mammals. We have previously shown that ooc-5 and ooc-3 mutations result in defects in spindle orientation and polarity in early C. elegans embryos. In particular, mutations in these genes affect the re-establishment of PAR protein asymmetry in the P(1) cell of two-cell embryos. We now report that ooc-5 encodes a putative ATPase of the Clp/Hsp100 and AAA superfamilies of proteins, with highest sequence similarity to Torsin proteins; the gene for human Torsin A is mutated in individuals with early-onset torsion dystonia, a neuromuscular disease. Although Clp/Hsp100 and AAA family proteins have roles in diverse cellular activities, many are involved in the assembly or disassembly of proteins or protein complexes; thus, OOC-5 may function as a chaperone. OOC-5 protein co-localizes with a marker of the endoplasmic reticulum in all blastomeres of the early C. elegans embryo, in a pattern indistinguishable from that of OOC-3 protein. Furthermore, OOC-5 localization depends on the normal function of the ooc-3 gene. These results suggest that OOC-3 and OOC-5 function in the secretion of proteins required for the localization of PAR proteins in the P(1) cell, and may have implications for the study of torsion dystonia.
Basham
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Section of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA.
Rose
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D000251:Adenosine Triphosphatases / Q000235:genetics*; D000818:Animals; D001757:Blastomeres; D019521:Body Patterning / Q000235:genetics; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics*; D019070:Cell Lineage; D016764:Cell Polarity / Q000235:genetics*; D003001:Cloning, Molecular; D049071:Endopeptidase Clp; D004721:Endoplasmic Reticulum / Q000201:enzymology; D005854:Germ Cells; D005934:Glucagon / Q000302:isolation & purification; D052216:Glucagon-Like Peptide 1; D006360:Heat-Shock Proteins / Q000235:genetics; D007422:Intestines / Q000166:cytology; D008565:Membrane Proteins / Q000235:genetics; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D010446:Peptide Fragments / Q000302:isolation & purification; D011498:Protein Precursors / Q000302:isolation & purification; D015800:Protozoan Proteins / Q000235:genetics; D012697:Serine Endopeptidases / Q000235:genetics
D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; C491548:Dyt1 protein, mouse; D006360:Heat-Shock Proteins; D008565:Membrane Proteins; D018832:Molecular Chaperones; D010446:Peptide Fragments; D011498:Protein Precursors; D015800:Protozoan Proteins; C400325:Tor1b protein, mouse; C410544:ooc-3 protein, C elegans; D052216:Glucagon-Like Peptide 1; D005934:Glucagon; D012697:Serine Endopeptidases; D049071:Endopeptidase Clp; D000251:Adenosine Triphosphatases; C442329:OOC-5 protein, C elegans; C095049:ClpB protein, Leishmania