Heparan sulfate 6-O-endosulfatases: discrete in vivo activities and functional co-operativity.
HS (heparan sulfate) is essential for normal embryonic development. This requirement is due to the obligatory role for HS in the signalling pathways of many growth factors and morphogens that bind to sulfated domains in the HS polymer chain. The sulfation patterning of HS is determined by a complex interplay of Golgi-located N- and O-sulfotransferases which sulfate the heparan precursor and cell surface endosulfatases that selectively remove 6-O-sulfates from mature HS chains. In the present study we generated single or double knock-out mice for the two murine endosulfatases mSulf1 and mSulf2. Detailed structural analysis of HS from mSulf1-/- fibroblasts showed a striking increase in 6-O-sulfation, which was not seen in mSulf2-/- HS. Intriguingly, the level of 6-O-sulfation in the double mSulf1-/-/2-/- HS was significantly higher than that observed in the mSulf1-/- counterpart. These data imply that mSulf1 and mSulf2 are functionally co-operative. Unlike their avian orthologues, mammalian Sulf activities are not restricted to the highly sulfated S-domains of HS. Mitogenesis assays with FGF2 (fibroblast growth factor 2) revealed that Sulf activity decreases the activating potential of newly-synthesized HS, suggesting an important role for these enzymes in cell growth regulation in embryonic and adult tissues.
Lamanna
William C
WC
Department of Chemistry, Biochemistry I, Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany.
Baldwin
Rebecca J
RJ
Padva
Michael
M
Kalus
Ina
I
Ten Dam
Gerdy
G
van Kuppevelt
Toin H
TH
Gallagher
John T
JT
von Figura
Kurt
K
Dierks
Thomas
T
Merry
Catherine L R
CL
D000818:Animals; D000906:Antibodies / Q000276:immunology / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004187:Disaccharides / Q000032:analysis; D000939:Epitopes / Q000276:immunology; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005838:Genotype; D006497:Heparan Sulfate / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D015394:Molecular Structure; D009844:Oligosaccharides / Q000032:analysis; D013429:Sulfatases / Q000235:genetics / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism; D015238:Sulfotransferases / Q000235:genetics / Q000378:metabolism*
D000906:Antibodies; D004187:Disaccharides; D000939:Epitopes; D016222:Fibroblast Growth Factor 2; D006497:Heparan Sulfate; D009844:Oligosaccharides; D013429:Sulfatases; D013431:Sulfates; D015238:Sulfotransferases; C486773:Sulf1 protein, mouse; C514911:Sulf2 protein, mouse