The human receptor for urokinase plasminogen activator. NH2-terminal amino acid sequence and glycosylation variants
Research output: Contribution to journal › Journal article › Research › peer-review
The receptor for human urokinase-type plasminogen activator (u-PA) was purified from phorbol 12-myristate 13-acetate-stimulated U937 cells by temperature-induced phase separation of detergent extracts, followed by affinity chromatography with immobilized diisopropyl fluorophosphate-treated u-PA. The purified protein shows a single 55-60 kDa band after sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining. It is a heavily glycosylated protein, the deglycosylated polypeptide chain comprising only 35 kDa. The glycosylated protein contains N-acetyl-D-glucosamine and sialic acid, but no N-acetyl-D-galactosamine. Glycosylation is responsible for substantial heterogeneity in the receptor on phorbol ester-stimulated U937 cells, and also for molecular weight variations among various cell lines. The amino acid composition and the NH2-terminal amino acid sequence are reported. The protein has a high content of cysteine residues. The NH2-terminal sequence is not closely related to any known sequence. The identification of the purified and sequenced protein with the human u-PA receptor is based on the following findings: 1) the ability of the purified protein to bind u-PA and its amino-terminal fragment; 2) the identical electrophoretic mobilities observed for cross-linked conjugates, formed between either the purified protein or the u-PA receptor on intact U937 cells and the above ligands; 3) the identity of the apparent molecular weight of the purified protein to that predicted for the u-PA receptor in the same cross-linking studies; 4) the identical extent of glycosylation of the purified protein and of the u-PA receptor in crude membrane fractions, as detected after cross-linking; 5) the ability of antibodies raised against the purified protein to inhibit cellular binding of the amino-terminal fragment of u-PA.
Original language | English |
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Journal | The Journal of Biological Chemistry |
Volume | 265 |
Issue number | 11 |
Pages (from-to) | 6453-60 |
Number of pages | 8 |
ISSN | 0021-9258 |
Publication status | Published - 15 Apr 1990 |
Externally published | Yes |
- Amino Acid Sequence, Amino Acids, Cell Line, Chromatography, Affinity, Electrophoresis, Polyacrylamide Gel, Enzyme Precursors, Genetic Variation, Glycosylation, Humans, Molecular Sequence Data, Molecular Weight, Receptors, Cell Surface, Receptors, Urokinase Plasminogen Activator, Tetradecanoylphorbol Acetate, Urokinase-Type Plasminogen Activator, Journal Article, Research Support, Non-U.S. Gov't
Research areas
ID: 178214871