TY - JOUR

T1 - A urokinase receptor-associated protein with specific collagen binding properties

AU - Behrendt, N

AU - Jensen, O N

AU - Engelholm, L H

AU - Mørtz, E

AU - Mann, M

AU - Danø, K

PY - 2000

Y1 - 2000

N2 - The plasminogen activation cascade system, directed by urokinase and the urokinase receptor, plays a key role in extracellular proteolysis during tissue remodeling. To identify molecular interaction partners of these trigger proteins on the cell, we combined covalent protein cross-linking with mass spectrometry based methods for peptide mapping and primary structure analysis of electrophoretically isolated protein conjugates. A specific tri-molecular complex was observed upon addition of pro-urokinase to human U937 cells. This complex included the urokinase receptor, pro-urokinase, and an unknown, high molecular weight urokinase receptor-associated protein. The tryptic peptide mixture derived from a cross-linked complex of pro-urokinase and the latter protein was analyzed by nanoelectrospray tandem mass spectrometric sequencing. This analysis identified the novel protein as the human homologue of a murine membrane-bound lectin with hitherto unknown function. The human cDNA was cloned and sequenced. The protein, designated uPARAP, is a member of the macrophage mannose receptor protein family and contains a putative collagen-binding (fibronectin type II) domain in addition to 8 C-type carbohydrate recognition domains. It proved capable of binding strongly to a single type of collagen, collagen V. This collagen binding reaction at the exact site of plasminogen activation on the cell may lead to adhesive functions as well as a contribution to cellular degradation of collagen matrices.

AB - The plasminogen activation cascade system, directed by urokinase and the urokinase receptor, plays a key role in extracellular proteolysis during tissue remodeling. To identify molecular interaction partners of these trigger proteins on the cell, we combined covalent protein cross-linking with mass spectrometry based methods for peptide mapping and primary structure analysis of electrophoretically isolated protein conjugates. A specific tri-molecular complex was observed upon addition of pro-urokinase to human U937 cells. This complex included the urokinase receptor, pro-urokinase, and an unknown, high molecular weight urokinase receptor-associated protein. The tryptic peptide mixture derived from a cross-linked complex of pro-urokinase and the latter protein was analyzed by nanoelectrospray tandem mass spectrometric sequencing. This analysis identified the novel protein as the human homologue of a murine membrane-bound lectin with hitherto unknown function. The human cDNA was cloned and sequenced. The protein, designated uPARAP, is a member of the macrophage mannose receptor protein family and contains a putative collagen-binding (fibronectin type II) domain in addition to 8 C-type carbohydrate recognition domains. It proved capable of binding strongly to a single type of collagen, collagen V. This collagen binding reaction at the exact site of plasminogen activation on the cell may lead to adhesive functions as well as a contribution to cellular degradation of collagen matrices.

KW - Amino Acid Sequence

KW - Animals

KW - Cloning, Molecular

KW - Collagen

KW - Cross-Linking Reagents

KW - Dose-Response Relationship, Drug

KW - Glycosylation

KW - Humans

KW - Mannose-Binding Lectins

KW - Mass Spectrometry

KW - Membrane Glycoproteins

KW - Mice

KW - Molecular Sequence Data

KW - Muscle, Smooth, Vascular

KW - Plasminogen Activators

KW - Protein Binding

KW - Protein Structure, Tertiary

KW - Receptors, Cell Surface

KW - Receptors, Urokinase Plasminogen Activator

KW - Sequence Homology, Amino Acid

KW - U937 Cells

KW - Journal Article

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

M3 - Journal article

C2 - 10636902

VL - 275

SP - 1993

EP - 2002

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 3

ER -