Production of the glycosylphosphatidylinositol-specific phospholipase D by the islets of Langerhans.
J Biol Chem
; 266(27): 17733-6, 1991 Sep 25.
Article
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| MEDLINE
| ID: mdl-1833386
ABSTRACT
A large number of diverse cell surface proteins are anchored to the cell membrane by a glycosylphosphatidylinositol (GPI) anchor. One proposed function for the GPI anchor is that it facilitates the release of the protein from the cell by acting as a target for anchor-specific phospholipases. We and others have discovered that mammalian plasma contains a GPI-specific phospholipase D (GPI-PLD) (Cardoso de Almeida, M. L., Turner, M. J., Stambuk, B. V., and Schenkman, S. (1988) Biochem, Biophys. Res. Commun. 150, 476-482; Davitz, M. A., Hereld, D., Shak, S., Krakow, J., Englund, P. T., and Nussenzweig, V. (1987) Science 238, 81-84; Low, M. G., and Prasad, A. R. S. (1988) Proc. Natl. Acad. Sci. U. S. A. 85, 980-984). Because the GPI-PLD recognizes a conserved portion of the anchor, all GPI-anchored proteins are potential substrates for the enzyme. We demonstrate in this communication the production of the plasma GPI-PLD by the islets of Langerhans. GPI-PLD enzymatic activity was found in dog pancreatic microsomes, but not pancreatic juice. Both the pancreatic and plasma enzymes were divalent cation-dependent and had identical substrate specificities. Purified murine islets of Langerhans, as well as alpha and beta cells, contained and released GPI-PLD activity. A GPI-PLD DNA fragment was amplified by polymerase chain reaction from a normal human islet cDNA library; the amplified fragment hybridized with the GPI-PLD cDNA clone. These findings represent the first demonstration of the production of the plasma GPI-PLD by a specific tissue site as well as cell type.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Fosfatidilinositoles
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Fosfolipasa D
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Glucolípidos
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Islotes Pancreáticos
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Microsomas
Límite:
Animals
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Humans
Idioma:
En
Revista:
J Biol Chem
Año:
1991
Tipo del documento:
Article