Modulation of testicular galactolipid sulphotransferase activity by phosphorylation. Stimulation of enzyme activity <i>in vitro</i> by an endogenous kinase

Sakac, Darinka; Lingwood, Clifford A.

doi:10.1042/bj2610423

Cited by 10 publications

(3 citation statements)

References 15 publications

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“…Human brain (post‐mortem) microsomes were prepared as described previously (Sundaram and Lev 1992). Assays for GalC sulfotransferase activity of brain tissue samples were similarly performed as described previously (Sakac and Lingwood 1989; Sundaram and Lev 1992). Differences between mean values were determined by nested anova analysis.…”

Section: Preparation and Assay For Galc Sulfotransferasementioning

confidence: 99%

Substantial sulfatide deficiency and ceramide elevation in very early Alzheimer's disease: potential role in disease pathogenesis

Han

Holtzman²,

McKeel

et al. 2002

Journal of Neurochemistry

567

514

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In addition to pathology in the gray matter, there are also abnormalities in the white matter in Alzheimer's disease (AD). Sulfatide species are a class of myelin-specific sphingolipids and are involved in certain diseases of the central nervous system. To assess whether sulfatide content in gray and white matter in human subjects is associated with both the presence of Alzheimer's disease (AD) pathology as well as the stage of dementia, we analyzed the sulfatide content of brain tissue lipid extracts by electrospray ionization mass spectrometry from 22 subjects whose cognitive status at time of death varied from no dementia to very severe dementia. All subjects with dementia had AD pathology. The results demonstrate that: (i) sulfatides were depleted up to 93% in gray matter and up to 58% in white matter from all examined brain regions from AD subjects with very mild dementia, whereas all other major classes of lipid (except plasmalogen) in these subjects were not altered in comparison to those from age-matched subjects with no dementia; (ii) there was no apparent deficiency in the biosynthesis of sulfatides in very mild AD subjects as characterized by the examination of galactocerebroside sulfotransferase activities in post-mortem brain tissues; (iii) the content of ceramides (a class of potential degradation products of sulfatides) was elevated more than three-fold in white matter and peaked at the stage of very mild dementia. The findings demonstrate that a marked decrease in sulfatides is associated with AD pathology even in subjects with very mild dementia and that these changes may be linked with early events in the pathological process of AD.

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Section: Preparation and Assay For Galc Sulfotransferasementioning

confidence: 99%

Substantial sulfatide deficiency and ceramide elevation in very early Alzheimer's disease: potential role in disease pathogenesis

Han

Holtzman²,

McKeel

et al. 2002

Journal of Neurochemistry

567

514

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“…The synthesis of SGG is a differentiation marker for zygotene and early pachytene spermatocytes in the rat (Lingwood, 1985a). The galactolipid sulfotransferase is regulated by a phosphorylation mechanism (Sakac and Lingwood, 1989), and once synthesized, SGG remains in the plasma membrane throughout the remainder of spermatogenesis without turnover (Kornblatt, 1979). Abnormalities in SGG biosynthesis can result in sterility .…”

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confidence: 99%

Studies on the spermatogenic sulfogalactolipid binding protein SLIP 1

Lingwood

Nutikka

1991

Journal Cellular Physiology

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We have purified the testicular sulfogalactolipid binding protein SLIP 1 and shown by photoaffinity labeling that it contains an ATP binding site. Purified SLIP 1 was fluorescently labeled and shown to retain specific sulfogalactolipid binding function. This probe was used to investigate the topology of SLIP 1 binding sites on testicular germ cells. The binding pattern precisely coincided with the previously demonstrated asymmetric surface domains of sulfogalactoglycerolipid (SGG). Occasionally these SGG-containing, SLIP 1-binding cell surface domains exactly coincided with structural features on the cell surface as detected by differential interference contrast microscopy. These results demonstrate that SLIP 1/SGG interactions could provide an effective intercellular communication network between testicular germ cells within the seminiferous tubule.

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“…der of spermatogenesis (Kornblatt, 1979) and is involved in the mechanism of sperm/egg binding (Tanphaichitr et al, 1992(Tanphaichitr et al, , 1993. The galactolipid sulfotransferase, which has recently been purified (Sakac and Lingwood, 1989), is regulated by a phosphorylation mechanism (Sakac and Lingwood, 1989;Taylor et al, 1987). The enzyme is stimulated early in spermatogenesis by a stimulatory protein kinase and subsequent inhibition of phosphorylation results in reduction in enzyme activity.…”

Section: Introductionmentioning

confidence: 99%

Developmentally regulated testicular galactolipid sulfotransferase inhibitor is a phosphoinositol glycerolipid and insulin‐mimetic

Lingwood

Sakac

Saltiel³

1994

Molecular Reproduction Devel

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The synthesis of sulfogalactosylglycerolipid (SGG) is a differentiation marker in spermatogenesis restricted to the zygotene and early pachytene spermatocytes. The galactolipid sulfotransferase responsible for the synthesis of SGG is regulated by a phosphorylation mechanism. The activity of this enzyme is reduced in cells later in spermatogenesis by a low molecular weight inhibitor, which can be extracted in organic solvents and purified by reverse phase high pressure liquid chromatography (HPLC). This purified inhibitor is a potent postreceptor insulin-mimetic, which stimulates adipocyte lipogenesis more effectively than does insulin. Phosphoinositol (PI) glycolipids have been proposed as second messengers of the insulin phosphorylation cascade. These species contain a nonacetylated glucosamine, which renders them liable to cleavage by deamidation. The activity of the sulfotransferase inhibitor was lost following nitrous acid deamidation and was labile to PI specific phospholipase C digestion. Insulin and insulin-like growth factor I were found to inhibit germ cell synthesis of SGG in vitro to some degree but had no direct effect on the testicular galactolipid sulfotransferase assay. These results indicate that the sulfotransferase inhibitor is a glycosyl phosphoinositide similar to the lipid species, which mediate insulin signal transduction and suggest that germ cell SGG biosynthesis may be regulated by a receptor-mediated phosphorylation pathway.

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Modulation of testicular galactolipid sulphotransferase activity by phosphorylation. Stimulation of enzyme activity in vitro by an endogenous kinase

Cited by 10 publications

References 15 publications

Substantial sulfatide deficiency and ceramide elevation in very early Alzheimer's disease: potential role in disease pathogenesis

Substantial sulfatide deficiency and ceramide elevation in very early Alzheimer's disease: potential role in disease pathogenesis

Studies on the spermatogenic sulfogalactolipid binding protein SLIP 1

Developmentally regulated testicular galactolipid sulfotransferase inhibitor is a phosphoinositol glycerolipid and insulin‐mimetic

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