Glycolipid-anchored acetylcholinesterases from rabbit lymphocytes and erythrocytes differ in their sensitivity to phosphatidylinositol-specific phospholipase C

Richier, Patricia; Arpagaus, Martine; Toutant, Jean‐Pierre

doi:10.1016/0005-2736(92)90257-m

Cited by 24 publications

(11 citation statements)

References 36 publications

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“…This suggests that the apical surface of MDCK cells may be less accessible to PI‐PLC or that a subset of GPI‐APs on this surface are modified thus rendering them resistant to PI‐PLC cleavage. Consistent with the latter, resistance to PI‐PLC has been observed previously in erythrocytes and is due to acylation of the GPI inositol . We did observe less enrichment upon PI‐PLC treatment in the apical samples (1.4‐fold) as compared to the BL surface (3.0‐fold; Supporting Information Table 6) suggesting that perhaps some apical GPI‐APs are resistant to PI‐PLC cleavage.…”

Section: Discussionsupporting

confidence: 90%

Proteomic identification of mammalian cell surface derived glycosylphosphatidylinositol‐anchored proteins through selective glycan enrichment

et al. 2014

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Glycosylphosphatidylinositol-anchored proteins (GPI-APs) are an important class of glycoproteins that are tethered to the surface of mammalian cells via the lipid GPI. GPI-APs have been implicated in many important cellular functions including cell adhesion, cell signaling, and immune regulation. Proteomic identification of mammalian GPI-APs en masse has been limited technically by poor sensitivity for these low abundance proteins and the use of methods that destroy cell integrity. Here, we present methodology that permits identification of GPI-APs liberated directly from the surface of intact mammalian cells through exploitation of their appended glycans to enrich for these proteins ahead of LC-MS/MS analyses. We validate our approach in HeLa cells, identifying a greater number of GPI-APs from intact cells than has been previously identified from isolated HeLa membranes and a lipid raft preparation. We further apply our approach to define the cohort of endogenous GPI-APs that populate the distinct apical and basolateral membrane surfaces of polarized epithelial cell monolayers. Our approach provides a new method to achieve greater sensitivity in the identification of low abundance GPI-APs from the surface of live cells and the nondestructive nature of the method provides new opportunities for the temporal or spatial analysis of cellular GPI-AP expression and dynamics.

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Section: Discussionsupporting

confidence: 90%

Proteomic identification of mammalian cell surface derived glycosylphosphatidylinositol‐anchored proteins through selective glycan enrichment

et al. 2014

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“…Alternatively, the true GPI precursors (which could be very minor species) may be PI-PLC sensitive and processed, in some cases, to PI-PLC-resistant forms after transfer to protein, as described recently for alkaline phosphatase in HeLa cells (Wong and Low, 1994). Either model could explain why the proportion of PI-PLC-sensitive proteins varies with the cell line (Toutant et al, 1990;Richier et al, 1992;Wong and Low, 1992) without having to necessarily postulate the existence of an inositol deacylase in mammalian cells.…”

Section: Discussionmentioning

confidence: 94%

The role of inositol acylation and inositol deacylation in GPI biosynthesis in Trypanosoma brucei.

1995

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The compound diisopropylfluorophosphate (DFP) selectively inhibits an inositol deacylase activity in living trypanosomes that, together with the previously described phenylmethylsulfonyl fluoride (PMSF)-sensitive inositol acyltransferase, maintains a dynamic equilibrium between the glycosylphosphatidylinositol (GPI) anchor precursor, glycolipid A [NH2(CH2)2PO4-6Manal-2Manal-6Manal-4GlcNal-6myo-inositol-1-P04-sn-1,2-dimyristoylglycerol], and its inositol acylated form, glycolipid C. Experiments using DFP in living trypanosomes and a trypanosome cell-free system suggest that earlier GPI intermediates are also in equilibrium between their inositol acylated and nonacylated forms. However, unlike mammalian and yeast cells, bloodstream form trypanosomes do not appear to produce an inositol acylated form of glucosaminylphosphatidylinositol (GlcN-PI). A specific function of inositol acylation in trypanosomes may be to enhance the efficiency of ethanolamine phosphate addition to the Man3GlcN-(acyl)PI intermediate. Inositol deacylation appears to be a prerequisite for fatty acid remodelling of GPI intermediates that leads to the exclusive presence of myristic acid in glycolipid A and, ultimately, in the variant surface glycoprotein (VSG). In the presence of DFP, the de novo synthesis of GPI precursors cannot proceed beyond glycolipid C' (the unremodelled version of glycolipid C) and lyso-glycolipid C'. Under these conditions glycolipid C'-type GPI anchors appear on newly synthesized VSG molecules. However, the efficiencies of both anchor addition to VSG and N-glycosylation of VSG were significantly reduced. A modified model of the GPI biosynthetic pathway in bloodstream form African trypanosomes incorporating these findings is presented.

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“…These residues are also found at conserved positions in the C-terminal region of the T subunit of Torpedo AChE and even in hydrophilic ACE-1 AChE from the nematode Cnenorhabditis elegans [36]. Rabbit AChE is found under G1 and G2 amphiphilic forms of class I1 or hydrophilic forms in most tissues [37, 381 except in red [38] and white blood cells [39] where amphiphilic G2 forms of class I (possessing a glycolipid anchor) are found. Rabbit BChE is found predominantly as hydrophilic forms (our present observations), although a few amphiphilic forms of class I1 may exist similar to those in rat intestine [40].…”

Section: Comparison Of Rabbit Ache and Bche Sequencesmentioning

confidence: 99%

“…However, white blood cells can migrate outside capillary walls and invade pulmonary parenchyme. This could explain some ACHE trancripts and AChE activity since rabbit white cells were reported to be exceptionally rich in AChE [39]. Cholinergic innervation of heart and lung also may explain the presence of some AChE activity but no ACHE transcripts.…”

Section: Comparison Of Ache and Bche Expression In Rabbit Tissuesmentioning

confidence: 99%

Acetylcholinesterase and Butyrylcholinesterase Expression in Adult Rabbit Tissues and During Development

Jbilo¹,

L'Hermite²,

Talesa

et al. 1994

European Journal of Biochemistry

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A large cDNA fragment covering the complete sequence of the mature catalytic subunit of rabbit acetylcholinesterase (AChE) has been cloned and sequenced. This sequence was compared to that of rabbit butyrylcholinesterase [BChE;Jbilo, 0. & Chatonnet, A. (1990) Nucleic Acids Res. 18, 39901. Amino acid sequences of AChE and BChE have 51% identity. They both possessed a choline-binding site W84, a catalytic triad S200-H440-E327 and six cysteine residues (positions 67 -94, 254-265, 402-521) in conserved sequence positions to those that form three intrachain disulfide bonds in all cholinesterases (by convention, numbering of amino acids is that used for Torpedo AChE). Rabbit AChE had a larger number of aromatic residues lining the active-site gorge than rabbit BChE (14 compared to 8, respectively) and a smaller number of potential N-glycosylation sites (3 compared to 8, respectively). Both catalytic subunits have a hydrophilic C-terminus (catalytic subunits of type T). Expression of acetycholinesterase and butyrylcholinesterase genes (ACHE and BCHE) was studied in rabbit tissues and during development by a correlation of Northern-blot analysis and enzymic activities. This correlation was rendered difficult by the presence of an eserineresistant esterase active on butyrylthiocholine in serum, liver and lung. When the contribution of this carboxylesterase was taken into account, brain was found as the richest source of BChE followed by lung and heart. Rabbit liver had a very low content of BChE that correlated with the low BChE activity in plasma. During development, BCHE transcripts were detected as early as day 10 post coitum, whereas ACHE transcripts appeared only on day 12.Acetylcholinesterase belongs to a large family of proteins with conserved overall structure [l]. Functions of those proteins range from cell adhesion (as exemplified by glutactin and neurotactin) to detoxification (as liver carboxylesterases) and to the rapid hydrolysis of acetylcholine and other choline esters (cholinesterases). In vertebrates, two related enzymes : acetylcholinesterase (ACE) and butyrylcholinesterase (BChE) are able to hydrolyze acetylcholine and are inhibited by 0.01 mM eserine. Both enzymes present the same molecular forms, including globular and asymmetric molecules (reviews in [2, 31). The mechanisms of choline ester hydrolysis are basically the same in both enzymes [4] ; the substrate is directed to the bottom of a deep gorge by a series of aromatic Abbreviations. AChE and BChE, acetylcholinesterase and butyrylcholinesterase enzymes ; ACHE and BCHE, genes encoding AChE and BChE; Brij 96, 10-oleylether; Iso-OMPA, tetranionoisopropylpyrophosphortetramide; LS, LSB, HS and HSB, low salt, low-salt Brij, high salt and high-salt Brij buffers.

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Glycolipid-anchored acetylcholinesterases from rabbit lymphocytes and erythrocytes differ in their sensitivity to phosphatidylinositol-specific phospholipase C

Cited by 24 publications

References 36 publications

Proteomic identification of mammalian cell surface derived glycosylphosphatidylinositol‐anchored proteins through selective glycan enrichment

Proteomic identification of mammalian cell surface derived glycosylphosphatidylinositol‐anchored proteins through selective glycan enrichment

The role of inositol acylation and inositol deacylation in GPI biosynthesis in Trypanosoma brucei.

Acetylcholinesterase and Butyrylcholinesterase Expression in Adult Rabbit Tissues and During Development

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