title: Phylogenetic conservation of the cell-type-specific Lan3-2 glycoepitope in Caenorhabditis elegans.
abstract: The biological function of a cell-type-specific glycosylation of an adhesion molecule belonging to the L1CAM immunoglobulin superfamily was previously determined in the nervous system of the embryonic leech, Hirudo medicinalis. The Lan3-2 glycoepitope is a surface marker of sensory afferent neurons and is required for their appropriate developmental collateral branching and synaptogenesis in the CNS. The chemical structure of the Lan3-2 glycoepitope consists of beta-(1,4)-linked mannopyranose. Here, we show the conservation of the cell-type-specific expression of this mannose polymer in Caenorhabditis elegans. The Lan3-2 glycoepitope is expressed on the cell surface of a subset of dissociated embryonic neurons and, in the adult worm, by the pharyngeal motor neuron, M5, and the chemosensory afferents, the amphids. Additionally, the vulval epithelium expresses the Lan3-2 glycoepitope in late L4 larvae and in adult hermaphrodites. To investigate proteins carrying this restrictively expressed glycoepitope, worm extract was immunoaffinity purified with Lan3-2 monoclonal antibody and Western blotted. A polyclonal antibody reactive with the cytoplasmic tail of LAD-1/SAX-7, a C. elegans member of the L1CAM family, recognizes a 270 kDa protein band while Lan3-2 antibody also recognizes a 190 kDa glycoform, its putative Lan3-2 ectodomain. Thus, in C. elegans, as in leech, the Lan3-2 epitope is located on a L1CAM homologue. The cell-type-specific expression of the Lan3-2 glycoepitope shared by leech and C. elegans will be useful for understanding how cell-type-specific glycoepitopes mediate cell-cell interactions during development.
authors.affiliation: Department of Physiology, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Harper C
authors.initials: HC
authors.lastname: Vansteenhouse
authors.forename: Zachary A
authors.initials: ZA
authors.lastname: Horton
authors.forename: Robert
authors.initials: R
authors.lastname: O'Hagan
authors.forename: Mei-Hui
authors.initials: MH
authors.lastname: Tai
authors.forename: Birgit
authors.initials: B
authors.lastname: Zipser
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015153:Blotting, Western; D017173:Caenorhabditis elegans / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D000939:Epitopes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019143:Evolution, Molecular; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006023:Glycoproteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D006031:Glycosylation; D008358:Mannose / Q000737:chemistry / Q000378:metabolism; D018613:Microscopy, Confocal; D009154:Mutation; D009420:Nervous System / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D010802:Phylogeny; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D029742:Caenorhabditis elegans Proteins; D000939:Epitopes; D006023:Glycoproteins; C555601:Lan3-2 protein, C elegans; D011134:Polysaccharides; D008358:Mannose