Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.2.2.7 (heparinase)
 1,270 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A particulate fraction was separated from endometrial scrapings of the uterus of hormone- or sham-treated ovariectomized rabbit. The effects of estrogen and progesterone on the incorporation of [35S]sulfate from 3'-[35S]phosphoadenosine 5'-phosphosulfate (PAPS) into endogenous acceptors in the particulate fraction were investigated. Estrogen increased the incorporation of [35S]sulfate, but progesterone suppressed this effect. The results of DEAE-Sephadex A-25 (Cl-form) column chromatography of the pronase digest of the 35S-labeled substances indicated that the fraction eluted with 0.9 M NaCl (0.9 Fr) was most sensitive to the hormones. The major component in 0.9 Fr was resistant to crude heparinase, whereas the minor component was susceptible to this enzyme. The present observation, together with previous findings, suggested that the former was sulfated glycopeptide and the latter heparan sulfate. The results of the present study indicated that PAPS can serve as the direct "activated" sulfate donor in the enzymatic sulfation of sulfated glycoprotein in the particulate fraction, that the sulfation is greatly stimulated by pre-treatment of the rabbit with estrogen, and that the estrogen effect is suppressed by progesterone.
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PMID:Hormonal effects on the sulfation of sulfated glycoprotein in a particulate fraction of the endometrium of rabbit uterus. 728 55

O-Sulfation at C-3 of N-sulfated GlcN units concludes polymer modification and the formation of antithrombin binding regions in the biosynthesis of heparin/heparan sulfate. The resulting GlcNSO3(3-OSO3) units are largely restricted to heparin chains with high affinity for antithrombin (HA heparin). Low affinity (LA) heparin fails to serve as a substrate in the 3-O-sulfotransferase reaction yet contains potential 3-O-sulfate acceptor sites (Kusche, M., Torri, G., Casu, B., and Lindahl, U. (1990) J. Biol. Chem. 265, 7292-7300), as verified in the present study using a novel sequencing procedure. O-Desulfated, re-N-sulfated LA heparin, as well as an octasaccharide fraction isolated after heparinase I digestion of LA heparin, both yielded labeled HA components following incubation with solubilized mouse mastocytoma microsomal enzymes and [35S]adenosine 3'-phosphate 5'phosphosulfate (PAPS), suggesting that the 3-O-sulfo-transferase may be inhibited by sulfated saccharide sequences outside the 3-O-sulfate acceptor region. Indeed, the addition of LA heparin precluded enzymatic 3-O-sulfation of a synthetic pentasaccharide substrate. The Km for the pentasaccharide was determined to approximately be 6 microM. Incubations of mixed pentasaccharide substrate and saccharide inhibitors revealed Ki values for intact LA heparin and for a heparin octasaccharide fraction of approximately 1.3 and approximately 0.7 microM, respectively. Inhibition experiments with selectively desulfated heparin indicated that both IdoA 2-O-sulfate and GlcN 6-O-sulfate groups contributed to the inhibition of the 3-O-sulfotransferase. By contrast, chondroitin sulfate or dermatan sulfate showed no significant inhibitory activity. It is proposed that the regulation of GlcN 3-O-sulfation during biosynthesis of heparin/heparan sulfate depends on the topological organization of the membrane-bound enzyme machinery in the intact cell.
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PMID:Biosynthesis of heparin/heparan sulfate. The D-glucosaminyl 3-O-sulfotransferase reaction: target and inhibitor saccharides. 774 62

Schmallenberg virus (SBV) is an insect-transmitted orthobunyavirus that can cause abortions and congenital malformations in the offspring of ruminants. Even though the two viral surface glycoproteins Gn and Gc are involved in host cell entry, the specific cellular receptors of SBV are currently unknown. Using genome-wide CRISPR-Cas9 forward screening, we identified 3'-phosphoadenosine 5'-phosphosulfate (PAPS) transporter 1 (PAPST1) as an essential factor for SBV infection. PAPST1 is a sulfotransferase involved in heparan sulfate proteoglycan synthesis encoded by the solute carrier family 35 member B2 gene (SLC35B2). SBV cell surface attachment and entry were largely reduced upon the knockout of SLC35B2, whereas the reconstitution of SLC35B2 in these cells fully restored their susceptibility to SBV infection. Furthermore, treatment of cells with heparinase diminished infection with SBV, confirming that heparan sulfate plays an important role in cell attachment and entry, although to various degrees, heparan sulfate was also found to be important to initiate infection by two other bunyaviruses, La Crosse virus and Rift Valley fever virus. Thus, PAPST1-triggered synthesis of cell surface heparan sulfate is required for the efficient replication of SBV and other bunyaviruses.IMPORTANCE SBV is a newly emerging orthobunyavirus (family Peribunyaviridae) that has spread rapidly across Europe since 2011, resulting in substantial economic losses in livestock farming. In this study, we performed unbiased genome-wide CRISPR-Cas9 screening and identified PAPST1, a sulfotransferase encoded by SLC35B2, as a host entry factor for SBV. Consistent with its role in the synthesis of heparan sulfate, we show that this activity is required for efficient infection by SBV. A comparable dependency on heparan sulfate was also observed for La Crosse virus and Rift Valley fever virus, highlighting the importance of heparan sulfate for host cell infection by bunyaviruses. Thus, the present work provides crucial insights into virus-host interactions of important animal and human pathogens.
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PMID:A Genome-Wide CRISPR-Cas9 Screen Reveals the Requirement of Host Cell Sulfation for Schmallenberg Virus Infection. 3252 52