title: Identification of novel chondroitin proteoglycans in Caenorhabditis elegans: embryonic cell division depends on CPG-1 and CPG-2.
abstract: Vertebrates produce multiple chondroitin sulfate proteoglycans that play important roles in development and tissue mechanics. In the nematode Caenorhabditis elegans, the chondroitin chains lack sulfate but nevertheless play essential roles in embryonic development and vulval morphogenesis. However, assignment of these functions to specific proteoglycans has been limited by the lack of identified core proteins. We used a combination of biochemical purification, Western blotting, and mass spectrometry to identify nine C. elegans chondroitin proteoglycan core proteins, none of which have homologues in vertebrates or other invertebrates such as Drosophila melanogaster or Hydra vulgaris. CPG-1/CEJ-1 and CPG-2 are expressed during embryonic development and bind chitin, suggesting a structural role in the egg. RNA interference (RNAi) depletion of individual CPGs had no effect on embryonic viability, but simultaneous depletion of CPG-1/CEJ-1 and CPG-2 resulted in multinucleated single-cell embryos. This embryonic lethality phenocopies RNAi depletion of the SQV-5 chondroitin synthase, suggesting that chondroitin chains on these two proteoglycans are required for cytokinesis.
authors.affiliation: Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA 92093, USA.
authors.forename: Sara K
authors.initials: SK
authors.lastname: Olson
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Bishop
authors.forename: John R
authors.initials: JR
authors.lastname: Yates
authors.forename: Karen
authors.initials: K
authors.lastname: Oegema
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Esko
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002455:Cell Division; D002686:Chitin / Q000378:metabolism; D011508:Chondroitin Sulfate Proteoglycans / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D016695:Glycosyltransferases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D040901:Proteomics; D034622:RNA Interference; D020539:Sequence Analysis, Protein
chemical_list: C512431:CPG-1 protein, C elegans; C512432:CPG-2 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D011508:Chondroitin Sulfate Proteoglycans; D002686:Chitin; D016695:Glycosyltransferases; C474582:sqv-5 protein, C elegans