scholarly journals Structure of the glycosylphosphatidylinositol membrane anchor of human placental alkaline phosphatase

1994 ◽  
Vol 302 (3) ◽  
pp. 861-865 ◽  
Author(s):  
C A Redman ◽  
J E Thomas-Oates ◽  
S Ogata ◽  
Y Ikehara ◽  
M A Ferguson
Keyword(s):  
Mass Spectrometry ◽  
Alkaline Phosphatase ◽  
Fast Atom Bombardment ◽  
Compositional Analysis ◽  
Hydrophobic Interaction Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Placental Alkaline Phosphatase ◽  
Membrane Anchor ◽  
Human Placental Alkaline Phosphatase ◽  
Ethanolamine Phosphate

The glycosylphosphatidylinositol membrane anchor of human placental alkaline phosphatase was isolated by exhaustive proteolysis followed by hydrophobic interaction chromatography. The resulting glycosylphosphatidylinositol-peptide was subjected to compositional analysis and chemical and enzymic modifications. The neutral-glycan fraction, prepared by dephosphorylation followed by HNO2 deamination and reduction, was sequenced using exoglycosidases and acetolysis. The phosphatidylinositol moiety was analysed by fast-atom bombardment mass spectrometry and gas chromatography-mass spectrometry. Taken together the data suggest the structure, Thr-Asp-ethanolamine-PO4-Man alpha 1-2Man alpha 1-6Man alpha 1-4GlcN-(sn-1-O- alkyl-2-O-acylglycerol-3-PO4-1-myo-D-inositol), which contains an additional ethanolamine phosphate group at an unknown position.

scholarly journals Structural studies on a lipoarabinogalactan of Crithidia fasciculata

1996 ◽  
Vol 313 (3) ◽  
pp. 963-971 ◽  
Author(s):  
Pascal SCHNEIDER ◽  
Achim TREUMANN ◽  
Kenneth G. MILNE ◽  
Malcolm J. McCONVILLE ◽  
Nicole ZITZMANN ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Mass Spectrometry ◽  
Leishmania Major ◽  
Hydrophobic Interaction Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Structural Studies ◽  
Donor Molecule ◽  
Membrane Anchor ◽  
Crithidia Fasciculata ◽  
Trypanosomatid Parasites

The monosaccharide D-arabinopyranose has only been found in glycoconjugates of the trypanosomatid parasites Leishmania major, Endotrypanum schaudinni and Crithidia fasciculata. The donor molecule for the relevant arabinosyltransferases is known to be GDP-α-D-Arap in L. major and C. fasciculata, and the latter organism is being used to study the biosynthesis of GDP-α-D-Arap. In this study, we describe the structure of the terminal product of arabinose metabolism in C. fasciculata, namely lipoarabinogalactan. This molecule was purified by hydrophobic-interaction chromatography and studied by a variety of techniques, including gas chromatography–mass spectrometry, electrospray mass spectrometry and chemical and enzymic digestions. These data show that lipoarabinogalactan contains a previously described D-arabino-D-galactan polysaccharide component covalently attached to a glycosylphosphatidylinositol type of membrane anchor that is similar to, but not identical with, that found in the lipophosphoglycans of the Leishmania.

scholarly journals The Promoter of the Rat Gonadotropin-Releasing Hormone Receptor Gene Directs the Expression of the Human Placental Alkaline Phosphatase Reporter Gene in Gonadotrope Cells in the Anterior Pituitary Gland as well as in Multiple Extrapituitary Tissues

Endocrinology ◽  
2004 ◽  
Vol 145 (2) ◽  
pp. 983-993 ◽  
Author(s):  
Anne Granger ◽  
Valérie Ngô-Muller ◽  
Christian Bleux ◽  
Céline Guigon ◽  
Hanna Pincas ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Reporter Gene ◽  
Transgene Expression ◽  
Pituitary Cells ◽  
Placental Alkaline Phosphatase ◽  
R Gene ◽  
Glycoprotein Hormone ◽  
Steroidogenic Factor 1 ◽  
Functional Sites ◽  
Human Placental Alkaline Phosphatase

Abstract Previous studies dealing with the mechanisms underlying the tissue-specific and regulated expression of the GnRH receptor (GnRH-R) gene led us to define several cis-acting regulatory sequences in the rat GnRH-R gene promoter. These include functional sites for steroidogenic factor 1, activator protein 1, and motifs related to GATA and LIM homeodomain response elements as demonstrated primarily in transient transfection assays in mouse gonadotrope-derived cell lines. To understand these mechanisms in more depth, we generated transgenic mice bearing the 3.3-kb rat GnRH-R promoter linked to the human placental alkaline phosphatase reporter gene. Here we show that the rat GnRH-R promoter drives the expression of the reporter gene in pituitary cells expressing the LHβ and/or FSHβ subunit but not in TSHβ- or GH-positive cells. Furthermore, the spatial and temporal pattern of the transgene expression during the development of the pituitary was compatible with that characterizing the emergence of the gonadotrope lineage. In particular, transgene expression is colocalized with the expression of the glycoprotein hormone α-subunit at embryonic day 13.5 and with that of steroidogenic factor 1 at later stages of pituitary development. Transgene expression was also found in specific brain areas, such as the lateral septum and the hippocampus. A single promoter is thus capable of directing transcription in highly diverse tissues, raising the question of the different combinations of transcription factors that lead to such a multiple, but nevertheless cell-specific, expressions of the GnRH-R gene.

scholarly journals GnRH Receptor Gene Expression in the Developing Rat Hippocampus: Transcriptional Regulation and Potential Roles in Neuronal Plasticity

Endocrinology ◽  
2010 ◽  
Vol 152 (2) ◽  
pp. 568-580 ◽  
Author(s):  
Anne-Laure Schang ◽  
Valérie Ngô-Muller ◽  
Christian Bleux ◽  
Anne Granger ◽  
Marie-Claude Chenut ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Neuronal Plasticity ◽  
Gnrh Receptor ◽  
Lateral Septum ◽  
Rat Hippocampus ◽  
Marker Genes ◽  
Mrna Levels ◽  
Primary Role ◽  
Placental Alkaline Phosphatase ◽  
Human Placental Alkaline Phosphatase

Abstract In the pituitary of mammals, the GnRH receptor (GnRHR) plays a primary role in the control of reproductive function. It is further expressed in the hippocampus, where its function, however, is not well defined. By quantitative RT-PCR analyses, we demonstrate herein that the onset of GnRHR gene (Gnrhr) expression in the rat hippocampus was unexpectedly delayed as compared to the pituitary and only occurred after birth. Using a previously described transgenic mouse model bearing the human placental alkaline phosphatase reporter gene under the control of the rat Gnrhr promoter, we established a positive correlation between the temporal pattern of Gnrhr mRNA levels and promoter activity in the hippocampal formation. The gradual appearance of human placental alkaline phosphatase transgene expression occurred simultaneously in the hippocampus and interconnected structures such as the lateral septum and the amygdala, coinciding with the establishment of hippocampo-septal projections. Analysis of transcription factors together with transient transfection assays in hippocampal neurons indicated that the combinatorial code governing the hippocampus-specific expression of the Gnrhr is distinct from the pituitary, likely involving transactivating factors such as NUR77, cyclic AMP response element binding protein, and Finkel-Biskis-Jinkins murine osteosarcoma virus oncogene homolog. A silencing transcription factor acting via the -3255/-1135 promoter region of the Gnrhr may be responsible for the transcriptional repression observed around birth. Finally, GnRH directly stimulated via activation of its receptor the expression of several marker genes of neuronal plasticity such as Egr1, synaptophysin, and spinophilin in hippocampal primary cultures, suggesting a role for GnRHR in neuronal plasticity. Further characterization of these mechanisms may help unravel important functions of GnRH/GnRHR signaling in the brain.

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