title: Disruption of somitogenesis by a novel dominant allele of Lfng suggests important roles for protein processing and secretion.
abstract: Vertebrate somitogenesis is regulated by a segmentation clock. Clock-linked genes exhibit cyclic expression, with a periodicity matching the rate of somite production. In mice, lunatic fringe (Lfng) expression oscillates, and LFNG protein contributes to periodic repression of Notch signaling. We hypothesized that rapid LFNG turnover could be regulated by protein processing and secretion. Here, we describe a novel Lfng allele (Lfng(RLFNG)), replacing the N-terminal sequences of LFNG, which allow for protein processing and secretion, with the N-terminus of radical fringe (a Golgi-resident protein). This allele is predicted to prevent protein secretion without altering the activity of LFNG, thus increasing the intracellular half-life of the protein. This allele causes dominant skeletal and somite abnormalities that are distinct from those seen in Lfng loss-of-function embryos. Expression of clock-linked genes is perturbed and mature Hes7 transcripts are stabilized in the presomitic mesoderm of mutant mice, suggesting that both transcriptional and post-transcriptional regulation of clock components are perturbed by RLFNG expression. Contrasting phenotypes in the segmentation clock and somite patterning of mutant mice suggest that LFNG protein may have context-dependent effects on Notch activity.
authors.affiliation: The Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Dustin R
authors.initials: DR
authors.lastname: Williams
authors.affiliation: The Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099, USA.
authors.forename: Emily T
authors.initials: ET
authors.lastname: Shifley
authors.affiliation: The Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Kara M
authors.initials: KM
authors.lastname: Braunreiter
authors.affiliation: The Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA cole.354@osu.edu.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Cole
mesh_terms: D000483:Alleles; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics; D019521:Body Patterning / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D005838:Genotype; D005964:Glucosyltransferases; D016695:Glycosyltransferases / Q000235:genetics / Q000502:physiology*; D006579:Heterozygote; D017403:In Situ Hybridization; D008297:Male; D008648:Mesoderm / Q000378:metabolism; D051379:Mice; D009154:Mutation; D010641:Phenotype; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000235:genetics*; D051880:Receptors, Notch / Q000378:metabolism; D015398:Signal Transduction; D019170:Somites / Q000502:physiology*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D005964:Glucosyltransferases; D016695:Glycosyltransferases; D011506:Proteins; D051880:Receptors, Notch; C430525:Hes7 protein, mouse; C498392:Lfng protein, mouse; C491317:Rfng protein, mouse
keywords: Lunatic fringe; Mouse; Notch; Post-transcriptional regulation; Segmentation clock; Somitogenesis