Non‐lytic release of acetylcholinesterase from erythrocytes by A phosphatidylinositol‐specific phospholipase C

Low, Martin G.; Finean, J.B.

doi:10.1016/0014-5793(77)80905-8

Cited by 192 publications

(65 citation statements)

References 7 publications

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“…A possible explanation would be the presence of other AChE forms in these membranes. A likely candidate would be G;, which is known to occur at cell surfaces, for example at presynaptic and postsynaptic sites in Torpedo electric organs 1481, in mammalian erythrocytes [49], and together with G$, in hepatocytes [SO]. G$ AChE has in fact recently been observed in a membrane fraction from chromaffin cells [Sl].…”

Section: Subcellular Localization Qf the Various Acheformsmentioning

confidence: 99%

Subcellular distribution of acetylcholinesterase forms in chromaffin cells

Bon

Bader

Aunis

et al. 1990

European Journal of Biochemistry

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The presence of acetylcholinesterase (AChE) in chromaffin granules has been controversial for a long time. We therefore undertook a study of AChE molecular forms in chromaffin cells and of their distribution during subcellular fractionation. We characterized four main AChE forms, three amphiphilic forms (G1a· G2a and G4a), and one non‐amphiphilic form (G4na). Each form shows the same molecular characteristics (sedimentation, electrophoretic migration, lectin interactions) in the different subcellular fractions. All forms are glycosylated and seem to possess both N‐linked and O‐linked carbohydrate chains. There are differences in the structure of the glycans carried by the different forms, as indicated by their interaction with some lectins. Glycophosphatidylinositol‐specific phospholipases C converted the G2a form, but not the other amphiphilic forms, into non‐amphiphilic derivatives. The distinct patterns of AChE molecular forms observed in various subcellular compartments indicate the existence of an active sorting process. G4na was concentrated in fractions of high density, containing chromaffin granules. We obtained evidence for the existence of a lighter fraction also containing chromogranin A, tetrabenazine‐binding sites and G4na AChE, which may correspond to immature, incompletely loaded granules or to partially emptied granules. The distribution of G4na during subcellular fractionation suggested that this form is largely, but not exclusively, contained in chromaffin granules, the membranes of which may contain low levels of the three amphiphilic forms.

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Section: Subcellular Localization Qf the Various Acheformsmentioning

confidence: 99%

Subcellular distribution of acetylcholinesterase forms in chromaffin cells

Bon

Bader

Aunis

et al. 1990

European Journal of Biochemistry

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“…The first indication that hydrophobic AChE might not be anchored via a hydrophobic polypeptide but by a different mechanism, came from the observation in the mid-1970's that AChE was solubilized from certain erythrocytes, in the absence of detergent, upon addition of phosphatidylinositolspecific phospholipase C from Staphyolococcus aureus [135]. Upon addition of this phospholipase to erythrocytes, AChE was released in a non-aggregating form; furthermore, its release involved neither cell lysis nor extensive phosphatidylinositol (PtdIns) hydrolysis [135 -1371.…”

Section: Evidence For Covalently Bound Phosphatidylinositol As Membramentioning

confidence: 99%

“…For instance, it is totally ineffective in solubilizing brain AChE in four mammalian species [148], although it has been reported to solubilize AChE from sheep basal ganglia [149]. In fact, even in some erythrocytes, such as human and mouse, it is only partially able to solubilize DS AChE, whereas it is able completely to solubilize AChE from bovine, porcine and rat erythrocytes [135,1481. The available data on the susceptibility to Pdtlns-specific phospholipase C of hydrophobic AChE in the tissues examined so far, including unpublished data from the authors' laboratory, are summarized in Table. 1.…”

Section: Evidence For Covalently Bound Phosphatidylinositol As Membramentioning

confidence: 99%

Modes of attachment of acetylcholinesterase to the surface membrane

Silman

Futerman

1987

European Journal of Biochemistry

173

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Acetylcholinesterase (AChE) occurs in multiple molecular forms differing in their quaternary structure and mode of anchoring to the surface membrane. Attachment is achieved by post‐translational modification of the catalytic subunits. Two such mechanisms are described. One involves attachment to catalytic subunit tetramers, via disulfide bridges, of a collagen‐like fibrous tail. This, in turn, interacts, primarily via ionic forces, with a heparin‐like proteoglycan in the extracellular matrix. A second such modification involve the covalent attachment of a single phosphatidylinositol molecule at the carboxyl‐terminus of each catalytic subunit polypeptide; the diacylglycerol moiety of the phospholipid serves to anchor the modified enzyme hydrophobically to the lipid bilayer of the plasma membrane. The detailed molecular structure of these two classes of acetylcholinesterase are discussed, as well as their biosynthesis and mode of anchoring.

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“…A few externally exposed plasma-membrane proteins from protozoan and mammalian origin, however, are anchored via a covalently attached glycolipid which contains phosphatidylinositol (PI), and these proteins can be released from the membranes by phospholipases C (PLC) [4,5]. The growing list of glycoproteins of this type comprises the variable surface glycoproteins (VSG) of trypanosomes [6,7], the p63 surface glycoprotein of Leishmania [8], the membrane forms of alkaline phosphatase [9], acetylcholinesterase [10], 5'-nucleotidase [ 1 1,12], the 120 kDa form of rodent neural-cell adhesion molecule ('NCAM') [13], and several immunologically relevant surface proteins such as decay-accelerating factor ('DAF') [14], the rat lymphocyte alloantigen RT-6.2 [15], the mouse Ly-6 antigen [16] and the Thy-I antigen of lymphocytes and brain cells [17,18]. Considerable chemical information exists about the membrane-anchoring glycolipid of VSG and Thy-i; amino-acid-sequencing studies revealed in both cases that the mature molecules lack a C-terminal stretch of hydrophobic amino acids predicted from the cDNA sequences [17,19,20].…”

Section: Introductionmentioning

confidence: 99%

Glycolipid anchors are attached to Thy-1 glycoprotein rapidly after translation

Conzelmann

Spiazzi

Bron

1987

Biochemical Journal

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The attachment of glycolipid anchors to the Thy-1 glycoprotein during biosynthesis was followed by the change of detergent-binding properties of biosynthetically labelled Thy-1 precursors upon phospholipase C treatment in the murine thymoma lines BW5147 and S1A. In S1A, 80% of the Thy-1 molecules were phospholipase-C-sensitive after a 2 min pulse with [35S]methionine, indicating that these molecules were already anchored via a glycolipid tail. In BW5147, 47% of the Thy-1 molecules had phospholipase-C-sensitive anchors attached after a 1.5 min labelling and, with longer pulses, this percentage rose to 76%. Tunicamycin did not block the addition of glycolipid anchors, and glycolipid attachment also occurred at 21 degrees C. The findings suggest that the attachment of glycolipid anchors occurs in the rough endoplasmic reticulum.

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Non‐lytic release of acetylcholinesterase from erythrocytes by A phosphatidylinositol‐specific phospholipase C

Cited by 192 publications

References 7 publications

Subcellular distribution of acetylcholinesterase forms in chromaffin cells

Subcellular distribution of acetylcholinesterase forms in chromaffin cells

Modes of attachment of acetylcholinesterase to the surface membrane

Glycolipid anchors are attached to Thy-1 glycoprotein rapidly after translation

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