HSulf sulfatases catalyze processive and oriented 6‐O‐desulfation of heparan sulfate that differentially regulates fibroblast growth factor activity

Abstract

Sulfs are extracellular sulfatases that have emerged recently as critical regulators of heparan sulfate (HS) activities through their ability to catalyze specific 6-O-desulfation of the polysaccharide. Consequently, Sulfs have been involved in many physiological and pathological processes, and notably for Sulf-2, in the development of cancers with poor prognosis. Despite growing interest, little is known about the structure and activity of these enzymes and the way they induce dynamic remodeling of HS 6-O-sulfation status. Here, we have combined an array of analytical approaches, including mass spectrometry, NMR, HS oligosaccharide sequencing, and FACS, to dissect HSulf-2 sulfatase activity, either on a purified octasaccharide used as a mimic of HS functional domains, or on intact cell-surface HS chains. In parallel, we have studied the functional consequences of HSulf-2 activity on fibroblast growth factor (FGF)-induced mitogenesis and found that the enzyme could differentially regulate FGF1 and FGF2 activities. Notably, these data supported the existence of precise 6-O-sulfation patterns for FGF activation and provided new insights into the saccharide structures involved. Altogether, our data bring to light an original processive enzymatic mechanism, by which HSulfs catalyze oriented alteration of HS 6-O-desulfation patterns and direct fine and differential regulation of HS functions.

Cloning and Characterization of a Novel Chondroitin Sulfate/Dermatan Sulfate 4-O-Endosulfatase from a Marine Bacterium

“…Together with the sulfatase reported here, however, only three GAG endosulfatases have yet been identified from animals (40) and bacteria (24). The roles of HS 6-O-endosulfatase in animals have been widely and actively studied in biological processes from embryo development to tumorigenesis (41)(42)(43). However, this enzyme has rarely been used as a tool for structurefunction studies of HS in vitro, which might be due to its low activity and instability.…”

Enhanced Tumorigenic Potential of Colorectal Cancer Cells by Extracellular Sulfatases

“…Seffouh and colleagues (43) have demonstrated that SULF1 and SULF2 share the same desulfation process, but with a different rate, whereas SULF1 showed a much stronger potency for in vitro desulfation of HS substrates. Moreover, data from the literature indicate that the substrate specificity of the SULFs remains unclear, because some methods are not sensitive enough to detect less abundant disaccharide units (26,43). However, in vivo and in vitro data indicate that these enzymes essentially exert their activity on UA2S-GlcNS6S units, which are found within HS S-domains, and to a much lesser extent on (UA-GlcNS6S) disulfated disaccharides.…”

“…It is important to point out, however, that discrepancies were previously observed between in vitro and in vivo studies involving SULFs (26,43). In vitro, the enzyme activity of the SULFs has been studied after near-exhaustive digestion of the polysaccharide.…”

“…In vitro, the enzyme activity of the SULFs has been studied after near-exhaustive digestion of the polysaccharide. However, in tissues, the extent of HS 6-O-desulfation by the SULFs is likely to depend on critical environmental factors, such as the amount of enzymes expressed, their ability to diffuse throughout tissues, or the structure and sulfation pattern of HS present in these tissues (43). The physiologic activity of the SULFs may therefore lead to partially desulfated HS chains, which may differentially affect binding of some HS ligands but not others, depending on the extent of desulfation.…”

Drosophila Sulf1 is required for the termination of intestinal stem cell division during regeneration

“…Specifically, the level of 6-O sulfation modulates the activities of various signaling molecules, such as FGF, Wnt and Hh (Ai et al, 2003;Danesin et al, 2006;Dhoot et al, 2001;Ma et al, 2011;Seffouh et al, 2013;Uchimura et al, 2006). To determine whether 6-O sulfation is key in the regulation of stem cell activity during midgut regeneration, we first determined expression patterns of Hs6st in the midgut using a Hs6st::EGFP protein-trap allele (Nagarkar-Jaiswal et al, 2015).…”