Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.6.1 (sulfatase)
 3,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of low (physiological) concentrations of insulin (2 and 20 ng/ml) and L-triiodothyronine (T3) were studied on two myelin-related enzymes: (1) the 3'-phosphoadenosine-5'-phosphosulfate:cerebroside sulfotransferase (CST, EC 2.8.2.11) catalyzing the production of sulfatide, and (2) the myelin enzyme, 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP, EC 3.1.4.3.7) in myelinogenic cultures of cells dissociated from embryonic mouse brain. Insulin treatment (20 ng/ml) of the cells in the presence of serum increased CST activity at 18 and 25 days in vitro (DIV) by 86 and 211%, respectively. At 18 DIV and under the same conditions, CNP was significantly stimulated (95%) by high doses of insulin (2,000 ng/ml) only, while arylsulfatase A (EC 3.1.6.1) or cerebroside sulfatase activities, both of which are involved in sulfatide degradation, were unchanged. Thus, it can be assumed that the observed increase of the incorporation of [35S]O4 into sulfatide after insulin treatment of mixed cell cultures is the result of CST induction rather than a decreased catabolism. The level of CST activity in insulin-treated cells (20 ng/ml) in serum-free medium was also increased at 18 and 25 DIV by about 50 and 70%, respectively. Conversely, none of the insulin concentrations used in the absence of serum (even at high doses) had any effect, either at 18 or 25 DIV on CNP and ASA activities. The involvement of insulin in the regulation of sulfatide synthesis was further confirmed by dose-response curves relating the activity of CST to hormone concentration in the medium. The increase in the activity of CST in insulin-treated cells was due only to the increase in the Vmax of this enzyme, suggesting that it may be attributed to enzyme induction. A study of kinetic parameters of CST indicated that there were no differences in pH optimum and Km values between control and induced enzyme. Further experiments using cycloheximide point to a direct effect of insulin on oligodendrocyte CST induction. Data similar to those described above for insulin were also obtained with T3. As for insulin, T3 stimulated the induction of CST but in serum-free medium only. This effect was prevented by cycloheximide. In addition, the induction of CST by T3 was blocked by actinomycin D. This was not the case for insulin. These results suggest that T3 and insulin act on CST by different mechanisms, i.e. at transcriptional and post-translational levels, respectively. Apart from this, the insulin effect on CST activity was additive to that of T3.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Comparison of the mechanisms of action of insulin and triiodothyronine on the synthesis of cerebroside sulfotransferase in cultures of cells dissociated from brains of embryonic mice. 218 27

Trembler mice are affected by dominantly inherited neuropathy. Total lipid content and sulfatides were decreased in peripheral nerves from 15-day-old mutants. The proportion of sulfatides in per cent of total lipids was similar in control and Trembler nerves. The specific activity of ceramide galactosyltrnsferase, the enzyme responsible for the synthesis of cerebrosides, was 36 and 13% of controls, in young and adult. Trembler nerves, respectively. In contrast, cerebroside sulfotransferase activities were increased by 257 and 172% in young and adult Trembler sciatic nerves, respectively. No activator or inhibitor effect could be demonstrated. In Trembler PNS, Km, Vmax and heat sensitivity of CST differed from controls. Low levels of substrate and high arylsulfatase A activity (218% of controls) could explain the lack of sulfatide accumulation. The increased in vivo sulfate and galactose incorporation into non-lipidic material couild reflect the overproduction of endoneurial and perineurial connective tissue, whereas the high turnover rate of sulfatides could be correlated with intense demyelination and remyelination observed in Trembler PNS.
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PMID:Abnormal sulfate metabolism in a hereditary demyelinating neuropathy. 610 27