A cleavage-resistant urokinase plasminogen activator receptor exhibits dysregulated cell-surface clearance.
J Biol Chem
; 285(17): 12595-603, 2010 Apr 23.
Article
em En
| MEDLINE
| ID: mdl-20177061
ABSTRACT
Urokinase plasminogen activator receptor (u-PAR) binds urokinase plasminogen activator (u-PA) and participates in plasminogen activation in addition to modulating several cellular processes such as adhesion, proliferation, and migration. u-PAR is susceptible to proteolysis by its cognate ligand and several other proteases. To elucidate the biological significance of receptor cleavage by u-PA, we engineered and expressed a two-chain urokinase plasminogen activator (tcu-PA) cleavage-resistant u-PAR (cr-u-PAR). This mutated receptor was similar to wild-type u-PAR in binding u-PA and initiating plasminogen activation. However, cr-u-PAR exhibited accelerated internalization and resurfacing due to direct association with the endocytic receptor alpha(2)-macroglobulin receptor/low density lipoprotein receptor-related protein in the absence of the enzyme x inhibitor complex of tcu-PA and plasminogen activator inhibitor-1 (tcu-PA.PAI-1). cr-u-PAR-expressing cells had enhanced migration compared with wild-type u-PAR-expressing cells, and cr-u-PAR was less sensitive to chymotrypsin cleavage as compared with wt u-PAR. Our studies suggest that these mutations in the linker region result in a rearrangement within the cr-u-PAR structure that makes it resemble its ligand-bound form. This constitutively active variant may mimic highly glycosylated cleavage-resistant u-PAR expressed in certain highly malignant cancer-cells.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ativador de Plasminogênio Tipo Uroquinase
/
Movimento Celular
/
Receptores de Ativador de Plasminogênio Tipo Uroquinase
Limite:
Humans
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article