Differential binding of urokinase and peptide antagonists to the urokinase receptor: evidence from characterization of the receptor in four primate species

TY - JOUR

T1 - Differential binding of urokinase and peptide antagonists to the urokinase receptor

T2 - evidence from characterization of the receptor in four primate species

AU - Engelholm, L H

AU - Behrendt, N

PY - 2001/3

Y1 - 2001/3

N2 - The urokinase plasminogen activator receptor (uPAR) is a membrane protein active in localizing the plasminogen activation cascade system on the cell surface. The resulting pericellular proteolytic activity is responsible for degradation reactions in the extracellular matrix that are needed for the invasion of cancer cells, thus making uPAR a potential target for anti-invasive therapy based on binding antagonists. A remarkable property of the uPA-uPAR system is a pronounced species specificity in ligand recognition. We have now cloned and studied uPAR from four primate species and show that even though these sequences contain very few substitutions relative to the human uPAR, the receptor protein products differ markedly in terms of ligand selectivity. Thus, a well described competitive peptide antagonist directed against the human uPAR reacts with only one of the monkey receptors (chimpanzee uPAR), in spite of the fact that uPAR from all of the four species cross-reacts with human uPA. Notably, uPAR from African green monkey, which is completely devoid of reactivity with the peptide, contains only three substitutions relative to chimpanzee uPAR in the molecular regions critical for binding. These findings aid the elucidation of the structure/function relationship of uPAR and, unexpectedly, identify a structural distinction governing the binding of uPA and a very similar peptide antagonist.

AB - The urokinase plasminogen activator receptor (uPAR) is a membrane protein active in localizing the plasminogen activation cascade system on the cell surface. The resulting pericellular proteolytic activity is responsible for degradation reactions in the extracellular matrix that are needed for the invasion of cancer cells, thus making uPAR a potential target for anti-invasive therapy based on binding antagonists. A remarkable property of the uPA-uPAR system is a pronounced species specificity in ligand recognition. We have now cloned and studied uPAR from four primate species and show that even though these sequences contain very few substitutions relative to the human uPAR, the receptor protein products differ markedly in terms of ligand selectivity. Thus, a well described competitive peptide antagonist directed against the human uPAR reacts with only one of the monkey receptors (chimpanzee uPAR), in spite of the fact that uPAR from all of the four species cross-reacts with human uPA. Notably, uPAR from African green monkey, which is completely devoid of reactivity with the peptide, contains only three substitutions relative to chimpanzee uPAR in the molecular regions critical for binding. These findings aid the elucidation of the structure/function relationship of uPAR and, unexpectedly, identify a structural distinction governing the binding of uPA and a very similar peptide antagonist.

KW - Amino Acid Sequence

KW - Animals

KW - Binding, Competitive

KW - Cloning, Molecular

KW - Haplorhini

KW - Humans

KW - Molecular Sequence Data

KW - Peptides

KW - Primates

KW - Receptors, Cell Surface

KW - Receptors, Urokinase Plasminogen Activator

KW - Sequence Homology, Amino Acid

KW - Species Specificity

KW - Urokinase-Type Plasminogen Activator

KW - Journal Article

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

U2 - 10.1515/BC.2001.053

DO - 10.1515/BC.2001.053

M3 - Journal article

C2 - 11347891

SN - 1431-6730

VL - 382

SP - 435

EP - 442

JO - Biological Chemistry

JF - Biological Chemistry

IS - 3

ER -