Drosophila heparan sulfate 6-O-sulfotransferase (dHS6ST) gene. Structure, expression, and function in the formation of the tracheal system.
Heparan sulfate, one of the most abundant components of the cell surface and the extracellular matrix, is involved in a variety of biological processes such as growth factor signaling, cell adhesion, and enzymatic catalysis. The heparan sulfate chains have markedly heterogeneous structures in which distinct sequences of sulfate groups determine specific binding properties. Sulfation at each different position of heparan sulfate is catalyzed by distinct enzymes, sulfotransferases. In this study, we identified and characterized Drosophila heparan sulfate 6-O-sulfotransferase (dHS6ST). The deduced primary structure of dHS6ST exhibited several common features found in those of mammalian HS6STs. We confirmed that, when the protein encoded by the cDNA was expressed in COS-7 cells, it showed HS6ST activity. Whole mount in situ hybridization revealed highly specific expression of dHS6ST mRNA in embryonic tracheal cells. The spatial and temporal pattern of dHS6ST expression in these cells clearly resembles that of the Drosophila fibroblast growth factor (FGF) receptor, breathless (btl). RNA interference experiments demonstrated that reduced dHS6ST activity caused embryonic lethality and disruption of the primary branching of the tracheal system. These phenotypes were reminiscent of the defects observed in mutants of FGF signaling components. We also show that FGF-dependent mitogen-activated protein kinase activation is significantly reduced in dHS6ST double-stranded RNA-injected embryos. These findings indicate that dHS6ST is required for tracheal development in Drosophila and suggest the evolutionally conserved roles of 6-O-sulfated heparan sulfate in FGF signaling.
Department of Biology, Tokyo Metropolitan University, Hachioji-shi, Tokyo 192-0397, Japan.
K
K
Kamimura
M
M
Fujise
F
F
Villa
S
S
Izumi
H
H
Habuchi
K
K
Kimata
H
H
Nakato
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002522:Chlorocebus aethiops; D017124:Conserved Sequence; D004331:Drosophila melanogaster / Q000196:embryology / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D004625:Embryo, Nonmammalian / Q000502:physiology; D005091:Exons; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D017344:Genes, Insect; D006801:Humans; D008322:Mammals; D051379:Mice; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015238:Sulfotransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014132:Trachea / Q000196:embryology / Q000254:growth & development; D014158:Transcription, Genetic; D014162:Transfection
D012333:RNA, Messenger; D011994:Recombinant Proteins; C485757:HS6ST2 protein, human; C485756:Hs6st1 protein, mouse; D015238:Sulfotransferases; C404189:heparan sulfate 6-O-sulfotransferase