title: SHH E176/E177-Zn2+conformation is required for signaling at endogenous sites.
abstract: Sonic hedgehog (SHH) is a master developmental regulator. In 1995, the SHH crystal structure predicted that SHH-E176 (human)/E177 (mouse) regulates signaling through a Zn2+-dependent mechanism. While Zn2+is known to be required for SHH protein stability, a regulatory role for SHH-E176 or Zn2+has not been described. Here, we show that SHH-E176/177 modulates Zn2+-dependent cross-linking in vitro and is required for endogenous signaling, in vivo. While ectopically expressed SHH-E176A is highly active, mice expressing SHH-E177A at endogenous sites (ShhE177A/-) are morphologically indistinguishable from mice lacking SHH (Shh-/-), with patterning defects in both embryonic spinal cord and forebrain. SHH-E177A distribution along the embryonic spinal cord ventricle is unaltered, suggesting that E177 does not control long-range transport. While SHH-E177A association with cilia basal bodies increases in embryonic ventral spinal cord, diffusely distributed SHH-E177A is not detected. Together, these results reveal a novel role for E177-Zn2+in regulating SHH signaling that may involve critical, cilia basal-body localized changes in cross-linking and/or conformation.
authors.affiliation: Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Developmental Biology, Stanley Manne Children's Research Institute, Box 204, 2430 N. Halsted, Chicago, IL 60614, USA.
authors.forename: Diana S
authors.initials: DS
authors.lastname: Himmelstein
authors.affiliation: Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Developmental Biology, Stanley Manne Children's Research Institute, Box 204, 2430 N. Halsted, Chicago, IL 60614, USA.
authors.forename: Ivelisse
authors.initials: I
authors.lastname: Cajigas
authors.affiliation: Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Developmental Biology, Stanley Manne Children's Research Institute, Box 204, 2430 N. Halsted, Chicago, IL 60614, USA.
authors.forename: Chunming
authors.initials: C
authors.lastname: Bi
authors.affiliation: Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Developmental Biology, Stanley Manne Children's Research Institute, Box 204, 2430 N. Halsted, Chicago, IL 60614, USA.
authors.forename: Brian S
authors.initials: BS
authors.lastname: Clark
authors.affiliation: Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Developmental Biology, Stanley Manne Children's Research Institute, Box 204, 2430 N. Halsted, Chicago, IL 60614, USA.
authors.forename: Grant
authors.initials: G
authors.lastname: Van Der Voort
authors.affiliation: Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Developmental Biology, Stanley Manne Children's Research Institute, Box 204, 2430 N. Halsted, Chicago, IL 60614, USA. Electronic address: j-kohtz@northwestern.edu.
authors.forename: Jhumku D
authors.initials: JD
authors.lastname: Kohtz
mesh_terms: D000818:Animals; D000906:Antibodies / Q000737:chemistry / Q000378:metabolism; D000918:Antibody Specificity / Q000276:immunology; D064652:Basal Bodies / Q000187:drug effects / Q000378:metabolism; D001483:Base Sequence; D002923:Cilia / Q000187:drug effects / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000378:metabolism; D004622:Embryo, Mammalian / Q000187:drug effects / Q000378:metabolism; D053823:Hedgehog Proteins / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D051379:Mice; D016548:Prosencephalon / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D011487:Protein Conformation; D055503:Protein Multimerization / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D013116:Spinal Cord / Q000187:drug effects / Q000196:embryology / Q000378:metabolism; D015032:Zinc / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000906:Antibodies; D003432:Cross-Linking Reagents; D053823:Hedgehog Proteins; D015032:Zinc