The Drosophila sugarless gene modulates Wingless signaling and encodes an enzyme involved in polysaccharide biosynthesis.
We have identified and characterized a Drosophila gene, which we have named sugarless, that encodes a homologue of vertebrate UDP-glucose dehydrogenase. This enzyme is essential for the biosynthesis of various proteoglycans, and we find that in the absence of both maternal and zygotic activities of this gene, mutant embryos develop with segment polarity phenotypes reminiscent to loss of either Wingless or Hedgehog signaling. To analyze the function of Sugarless in cell-cell interaction processes, we have focused our analysis on its requirement for Wingless signaling in different tissues. We report that sugarless mutations impair signaling by Wingless, suggesting that proteoglycans contribute to the reception of Wingless. We demonstrate that overexpression of Wingless can bypass the requirement for sugarless, suggesting that proteoglycans modulate signaling by Wingless, possibly by limiting its diffusion and thereby facilitating the binding of Wingless to its receptor. We discuss the possibility that tissue-specific regulation of proteoglycans may be involved in regulating both Wingless short- or long-range effects.
Häcker
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U
Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
Lin
X
X
Perrimon
N
N
D000595:Amino Acid Sequence; D000818:Animals; D019521:Body Patterning / Q000235:genetics; D004330:Drosophila / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins; D004625:Embryo, Nonmammalian / Q000378:metabolism*; D004817:Epidermis / Q000196:embryology / Q000378:metabolism; D017344:Genes, Insect; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009420:Nervous System / Q000196:embryology / Q000201:enzymology; D011509:Proteoglycans / Q000096:biosynthesis / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors; D014533:Uridine Diphosphate Glucose Dehydrogenase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D051155:Wnt1 Protein
D029721:Drosophila Proteins; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins; D019476:Insect Proteins; D011509:Proteoglycans; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D051155:Wnt1 Protein; C106185:engrailed homeobox proteins; C074622:wg protein, Drosophila; C077245:hh protein, Drosophila; D014533:Uridine Diphosphate Glucose Dehydrogenase