title: Syndecan defines precise spindle orientation by modulating Wnt signaling in C. elegans.
abstract: Wnt signals orient mitotic spindles in development, but it remains unclear how Wnt signaling is spatially controlled to achieve precise spindle orientation. Here, we show that C. elegans syndecan (SDN-1) is required for precise orientation of a mitotic spindle in response to a Wnt cue. We find that SDN-1 is the predominant heparan sulfate (HS) proteoglycan in the early C. elegans embryo, and that loss of HS biosynthesis or of the SDN-1 core protein results in misorientation of the spindle of the ABar blastomere. The ABar and EMS spindles both reorient in response to Wnt signals, but only ABar spindle reorientation is dependent on a new cell contact and on HS and SDN-1. SDN-1 transiently accumulates on the ABar surface as it contacts C, and is required for local concentration of Dishevelled (MIG-5) in the ABar cortex adjacent to C. These findings establish a new role for syndecan in Wnt-dependent spindle orientation.
authors.affiliation: Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA Department of Physiology, Tokyo Women's Medical University, School of Medicine, 8-1, Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
authors.forename: Katsufumi
authors.initials: K
authors.lastname: Dejima
authors.affiliation: Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92037-0407, USA.
authors.forename: Sukryool
authors.initials: S
authors.lastname: Kang
authors.affiliation: Department of Physiology, Tokyo Women's Medical University, School of Medicine, 8-1, Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
authors.forename: Shohei
authors.initials: S
authors.lastname: Mitani
authors.affiliation: Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92037-0407, USA.
authors.forename: Pamela C
authors.initials: PC
authors.lastname: Cosman
authors.affiliation: Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA chisholm@ucsd.edu.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Chisholm
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D018613:Microscopy, Confocal; D034622:RNA Interference; D008941:Spindle Apparatus / Q000502:physiology*; D053668:Syndecan-1 / Q000378:metabolism*; D060449:Wnt Signaling Pathway / Q000502:physiology*
chemical_list: D029742:Caenorhabditis elegans Proteins; C515316:Mig-5 protein, C elegans; D053668:Syndecan-1
keywords: C. elegans; Dishevelled; Embryo; Endocytosis; Heparan sulfate; Proteoglycan