Martin Hrabé de Angelis

Publications (4)89.04 Total impact

• Article: Ribosomal mutations cause p53-mediated dark skin and pleiotropic effects.

  Kelly A McGowan, Jun Z Li, Christopher Y Park, Veronica Beaudry, Holly K Tabor, Amit J Sabnis, Weibin Zhang, Helmut Fuchs, Martin Hrabé de Angelis, Richard M Myers, Laura D Attardi, Gregory S Barsh
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  ABSTRACT: Mutations in genes encoding ribosomal proteins cause the Minute phenotype in Drosophila and mice, and Diamond-Blackfan syndrome in humans. Here we report two mouse dark skin (Dsk) loci caused by mutations in Rps19 (ribosomal protein S19) and Rps20 (ribosomal protein S20). We identify a common pathophysiologic program in which p53 stabilization stimulates Kit ligand expression, and, consequently, epidermal melanocytosis via a paracrine mechanism. Accumulation of p53 also causes reduced body size and erythrocyte count. These results provide a mechanistic explanation for the diverse collection of phenotypes that accompany reduced dosage of genes encoding ribosomal proteins, and have implications for understanding normal human variation and human disease.
  Nature Genetics 08/2008; 40(8):963-70. · 35.53 Impact Factor
• Article: Identification of a Keratin 4 mutation in a chemically induced mouse mutant that models white sponge nevus.

  Kelly A McGowan, Helmut Fuchs, Martin Hrabé de Angelis, Gregory S Barsh
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  ABSTRACT: With the goal of increasing the number of genetic entry points for studying physiologic processes and human disease, large-scale, systematic, chemical mutagenesis projects in mice have been initiated in several different centers. We have been studying mouse mutants that exhibit dominantly inherited defects in either skin and/or hair color. Here, we describe a bright coat color mutant, Bright coat color 1 (Bcc1), which develops light-colored hair at 4 weeks of age, and when homozygous exhibits oral leukoplakia and blistering, and growth retardation. We identified a missense mutation in mutant animals that predicts an N154S amino-acid substitution in the 1A domain of Keratin 4 (encoded by the Krt2-4 gene), a region known to be mutated in human patients with white sponge nevus (WSN). Bcc1 recapitulates the gross pathologic, histologic, and genetic aspects of the human disorder, WSN.
  Journal of Investigative Dermatology 02/2007; 127(1):60-4. · 6.31 Impact Factor
• Article: Effects of G-protein mutations on skin color.

  Catherine D Van Raamsdonk, Karen R Fitch, Helmut Fuchs, Martin Hrabé de Angelis, Gregory S Barsh
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  ABSTRACT: A new class of dominant dark skin (Dsk) mutations discovered in a screen of approximately 30,000 mice is caused by increased dermal melanin. We identified three of four such mutations as hypermorphic alleles of Gnaq and Gna11, which encode widely expressed Galphaq subunits, act in an additive and quantitative manner, and require Ednrb. Interactions between Gq and Kit receptor tyrosine kinase signaling can mediate coordinate or independent control of skin and hair color. Our results provide a mechanism that can explain several aspects of human pigmentary variation and show how polymorphism of essential proteins and signaling pathways can affect a single physiologic system.
  Nature Genetics 10/2004; 36(9):961-8. · 35.53 Impact Factor
• Article: Genetics of dark skin in mice.

  Karen R Fitch, Kelly A McGowan, Catherine D van Raamsdonk, Helmut Fuchs, Daekee Lee, Anne Puech, Yann Hérault, David W Threadgill, Martin Hrabé de Angelis, Gregory S Barsh
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  ABSTRACT: Chemical mutagenesis in the mouse is a powerful approach for phenotype-driven genetics, but questions remain about the efficiency with which new mutations ascertained by their phenotype can be localized and identified, and that knowledge applied to a specific biological problem. During a global screen for dominant phenotypes in about 30,000 animals, a novel class of pigmentation mutants were identified by dark skin (Dsk). We determined the genetic map location, homozygous phenotype, and histology of 10 new Dsk and 2 new dark coat (Dcc) mutations, and identified mutations in Agouti (Met1Leu, Dcc4), Sox18 (Leu220ter, Dcc1), Keratin 2e (Thr500Pro, Dsk2), and Egfr (Leu863Gln, Dsk5). Cutaneous effects of most Dsk mutations are limited to melanocytes, except for the Keratin 2e and Egfr mutations, in which hyperkeratosis and epidermal thickening precede epidermal melanocytosis by 3-6 wk. The Dsk2 mutation is likely to impair intermediate filament assembly, leading to cytolysis of suprabasal keratinocytes and secondary hyperkeratosis and melanocytosis. The Dsk5 mutation causes increased tyrosine kinase activity and a decrease in steady-state receptor levels in vivo. The Dsk mutations represent genes or map locations not implicated previously in pigmentation, and delineate a developmental pathway in which mutations can be classified on the basis of body region, microscopic site, and timing of pigment accumulation.
  Genes & Development 02/2003; 17(2):214-28. · 11.66 Impact Factor