Cellular receptor for urokinase plasminogen activator. Carboxyl-terminal processing and membrane anchoring by glycosyl-phosphatidylinositol

TY - JOUR

T1 - Cellular receptor for urokinase plasminogen activator. Carboxyl-terminal processing and membrane anchoring by glycosyl-phosphatidylinositol

AU - Ploug, M

AU - Rønne, E

AU - Behrendt, N

AU - Jensen, Arne L

AU - Blasi, F.

AU - Danø, K

PY - 1991/1/25

Y1 - 1991/1/25

N2 - The cellular receptor for human urokinase-type plasminogen activator (u-PAR) is shown by several independent criteria to be a true member of a family of integral membrane proteins, anchored to the plasma membrane exclusively by a COOH-terminal glycosyl-phosphatidylinositol moiety. 1) Amino acid analysis of u-PAR after micropurification by affinity chromatography and N-[2-hydroxy-1,1-bis(hydroxymethyl)-ethyl]glycine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the presence of 2-3 mol of ethanolamine/mol protein. 2) Membrane-bound u-PAR is efficiently released from the surface of human U937 cells by trace amounts of purified bacterial phosphatidylinositol-specific phospholipase C. This soluble form of u-PAR retains the binding specificity toward both u-PA and its amino-terminal fragment holding the receptor-binding domain. 3) Treatment of purified u-PAR with phosphatidylinositol-specific phospholipase C or mild alkali completely alters the hydrophobic properties of the receptor as judged by temperature-induced detergent-phase separation and charge-shift electrophoresis. 4) Biosynthetic labeling of u-PAR was obtained with [3H]ethanolamine and myo-[3H]inositol. 5) Finally, comparison of amino acid compositions derived from cDNA sequence and amino acid analysis shows that a polypeptide of medium hydrophobicity is excised from the COOH terminus of the nascent u-PAR. A similar proteolytic processing has been reported for other proteins that are linked to the plasma membrane by a glycosyl-phosphatidylinositol membrane anchor.

AB - The cellular receptor for human urokinase-type plasminogen activator (u-PAR) is shown by several independent criteria to be a true member of a family of integral membrane proteins, anchored to the plasma membrane exclusively by a COOH-terminal glycosyl-phosphatidylinositol moiety. 1) Amino acid analysis of u-PAR after micropurification by affinity chromatography and N-[2-hydroxy-1,1-bis(hydroxymethyl)-ethyl]glycine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the presence of 2-3 mol of ethanolamine/mol protein. 2) Membrane-bound u-PAR is efficiently released from the surface of human U937 cells by trace amounts of purified bacterial phosphatidylinositol-specific phospholipase C. This soluble form of u-PAR retains the binding specificity toward both u-PA and its amino-terminal fragment holding the receptor-binding domain. 3) Treatment of purified u-PAR with phosphatidylinositol-specific phospholipase C or mild alkali completely alters the hydrophobic properties of the receptor as judged by temperature-induced detergent-phase separation and charge-shift electrophoresis. 4) Biosynthetic labeling of u-PAR was obtained with [3H]ethanolamine and myo-[3H]inositol. 5) Finally, comparison of amino acid compositions derived from cDNA sequence and amino acid analysis shows that a polypeptide of medium hydrophobicity is excised from the COOH terminus of the nascent u-PAR. A similar proteolytic processing has been reported for other proteins that are linked to the plasma membrane by a glycosyl-phosphatidylinositol membrane anchor.

KW - Amino Acids

KW - Ethanolamine

KW - Ethanolamines

KW - Glycolipids

KW - Glycosylphosphatidylinositols

KW - Humans

KW - In Vitro Techniques

KW - Membrane Glycoproteins

KW - Molecular Weight

KW - Phosphatidylinositol Diacylglycerol-Lyase

KW - Phosphatidylinositols

KW - Phosphoinositide Phospholipase C

KW - Phosphoric Diester Hydrolases

KW - Polysaccharides

KW - Protein Processing, Post-Translational

KW - Receptors, Cell Surface

KW - Receptors, Urokinase Plasminogen Activator

KW - Solubility

KW - Tumor Cells, Cultured

KW - Urokinase-Type Plasminogen Activator

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

M3 - Journal article

C2 - 1846368

SN - 0021-9258

VL - 266

SP - 1926

EP - 1933

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

IS - 3

ER -