Bud specific N-sulfation of heparan sulfate regulates Shp2-dependent FGF signaling during lacrimal gland induction.
Preferential outgrowth of the bud cells forms the basis of branching morphogenesis. Here, we show that lacrimal gland development requires specific modification of heparan sulfates by Ndst genes at the tip of the lacrimal gland bud. Systemic and conditional knockout experiments demonstrate the tissue specific requirement of Ndst1 and Ndst2 in the lacrimal gland epithelial, but not mesenchymal, cells, and the functional importance of Ndst1 in Fgf10-Fgfr2b, but not of Fgf1-Fgfr2b, complex formation. Consistent with this, Fgf10-induced ectopic lacrimal gland budding in explant cultures is dependent upon Ndst gene dose, and epithelial deletion of Fgfr2 abolishes lacrimal gland budding, its specific modification of heparan sulfate and its phosphorylation of Shp2 (Ptpn11 - Mouse Genome Informatics). Finally, we show that genetic ablation of Ndst1, Fgfr2 or Shp2 disrupts ERK signaling in lacrimal gland budding. Given the evolutionarily conserved roles of these genes, the localized activation of the Ndst-Fgfr-Shp2 genetic cascade is probably a general regulatory mechanism of FGF signaling in branching morphogenesis.
Pan
Yi
Y
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Carbe
Christian
C
Powers
Andrea
A
Zhang
Eric E
EE
Esko
Jeffrey D
JD
Grobe
Kay
K
Feng
Gen-Sheng
GS
Zhang
Xin
X
D000818:Animals; D004627:Embryonic Induction; D004848:Epithelium / Q000196:embryology / Q000201:enzymology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D051526:Fibroblast Growth Factor 10 / Q000235:genetics / Q000378:metabolism; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006497:Heparan Sulfate / Q000378:metabolism*; D019426:Integrases / Q000378:metabolism; D007765:Lacrimal Apparatus / Q000166:cytology / Q000196:embryology* / Q000201:enzymology; D051379:Mice; D009154:Mutation / Q000235:genetics; D009928:Organ Specificity; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11 / Q000235:genetics / Q000378:metabolism*; D051497:Receptor, Fibroblast Growth Factor, Type 2 / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D015238:Sulfotransferases / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism*
D048049:Extracellular Signal-Regulated MAP Kinases; D051526:Fibroblast Growth Factor 10; D005346:Fibroblast Growth Factors; D049452:Green Fluorescent Proteins; D006497:Heparan Sulfate; D019426:Integrases; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D051497:Receptor, Fibroblast Growth Factor, Type 2; D015238:Sulfotransferases; D013455:Sulfur; C045073:Cre recombinase; C021350:heparitin sulfotransferase; C516725:Ptpn11 protein, mouse