Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
 10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mutations in SRPX2 (Sushi-Repeat Protein, X-linked 2) cause rolandic epilepsy with speech impairment (RESDX syndrome) or with altered development of the speech cortex (bilateral perisylvian polymicrogyria). The physiological roles of SRPX2 remain unknown to date. One way to infer the function of SRPX2 relies on the identification of the as yet unknown SRPX2 protein partners. Using a combination of interactome approaches including yeast two-hybrid screening, co-immunoprecipitation experiments, cell surface binding and surface plasmon resonance (SPR), we show that SRPX2 is a ligand for uPAR, the urokinase-type plasminogen activator (uPA) receptor. Previous studies have shown that uPAR(-/-) knock-out mice exhibited enhanced susceptibility to epileptic seizures and had brain cortical anomalies consistent with altered neuronal migration and maturation, all features that are reminiscent to the phenotypes caused by SRPX2 mutations. SPR analysis indicated that the p.Y72S mutation associated with rolandic epilepsy and perisylvian polymicrogyria, led to a 5.8-fold gain-of-affinity of SRPX2 with uPAR. uPAR is a crucial component of the extracellular plasminogen proteolysis system; two more SRPX2 partners identified here, the cysteine protease cathepsin B (CTSB) and the metalloproteinase ADAMTS4, are also components of the extracellular proteolysis machinery and CTSB is a well-known activator of uPA. The identification of functionally related SRPX2 partners provides the first and exciting insights into the possible role of SRPX2 in the brain, and suggests that a network of SRPX2-interacting proteins classically involved in the proteolytic remodeling of the extracellular matrix and including uPAR participates in the functioning, in the development and in disorders of the speech cortex.
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PMID:Epileptic and developmental disorders of the speech cortex: ligand/receptor interaction of wild-type and mutant SRPX2 with the plasminogen activator receptor uPAR. 1871 38

The urokinase receptor (uPAR) is a multifunctional glycosylphosphatidylinositol-anchored protein that regulates important processes such as gene expression, cell proliferation, adhesion, migration, invasion, and metastasis. uPAR is an essential component of the plasminogen activation cascade, a protease receptor that binds the urokinase-type plasminogen activator. uPAR is also an adhesion-modulating receptor, and a signalling receptor transmitting signals to the cell through lateral interactions with a wide array of membrane receptors. Altogether, the external ligands and membrane-bound partners of uPAR constitute a rich uPAR interactome. Recently, a new ligand of uPAR has been identified as the SRPX2 protein which is essential in language and cognitive development. SRPX2 is the second identified gene involved in language disorders. However, previous studies revealed cognitive disorders and defects in the development of the GABAergic interneurons in uPAR null mice. In addition, the expression of uPAR correlates with important human diseases such as epilepsy, autism, multiple sclerosis, Alzheimer's, AIDS dementia, cerebral malaria, and brain tumours. Therefore, uPAR has unexpectedly become a significant receptor in the central nervous system and made a few steps into philosophy. Language is indeed intimately linked to human culture. This in-depth review presents the structure and the sequences of uPAR that are essential for drug design and the generation of new inhibitors. In addition, we summarize all the inhibitors of uPAR that have been created so far. Finally, we discuss the functions of uPAR in the development, functioning, and pathology of the central nervous system.
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PMID:The urokinase receptor in the central nervous system. 2087

As a key component of the plasminogen activation system, uPAR, the receptor for the plasminogen activator of the urokinase type, is involved in many physiological and pathological processes. Besides its classical roles, there has been increased evidence that uPAR or uPAR-associated pathways, participate in the development, in the functioning and in the pathology of the central nervous system. Qualitative and quantitative changes in the expressions of uPAR and of its canonical ligand uPA have been observed in a large variety of epileptic disorders, either in human or in animal models, as well as in other brain diseases (stroke and brain trauma, multiple sclerosis, Alzheimer's disease, cerebral malaria, HIV-associated leukoencephalopathy and encephalitis). The variety of such pathological conditions and the different brain areas and cell types involved, likely reflects the wide range and the complexity of the multiple and somehow intertwined pathophysiological mechanisms related with uPAR. In the mouse, the knock-out of the Upar-encoding gene (Plaur) leads to significant and nearly complete loss in parvalbumin-containing interneurons during brain development. This is associated with increased susceptibility to spontaneous and chemically-induced seizures and with increased anxiety and impaired social interactions. The recent identification of the novel uPAR ligand SRPX2 (Sushi repeat protein, X-linked 2) and the regulation of both the SRPX2 and PLAUR genes by transcription factor FOXP2 has shed novel and exciting insights into the role of uPAR-related molecular networks in rolandic epilepsy, in developmental verbal dyspraxia, in perisylvian polymicrogyria, and generally in disorders of the speech areas and circuits. uPAR, its regulators and partners, as well as other proteins containing Ly-6/uPAR/alpha-neurotoxin domains, represent key entry points for present and future studies not only on speech-related disorders but also on epilepsy and autism spectrum disorders.
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PMID:The role of the urokinase receptor in epilepsy, in disorders of language, cognition, communication and behavior, and in the central nervous system. 2171 Dec 33

The urokinase receptor (uPAR) was originally identified as the membrane receptor of the serine protease urokinase (uPA), thereby implicated in the plasminogen activation cascade and regulation of pericellular proteolysis. Later on, vitronectin was showed to be another major ligand providing uPAR with a role in cell adhesion. Other unrelated ligands have been subsequently reported including for example factor XII and SRPX2 expanding the functions of uPAR to unexpected biological areas such as the initiation of the coagulation cascade or the regulation of language development. Due to its glycosylphosphatidylinositol (GPI) anchor, uPAR has no intracellular domain and thus exerts its signaling capacity through lateral interactions with other components of the plasma membrane that actually mediate uPAR-induced signals. As yet, a total 42 proteins interacting directly with uPAR can be numbered comprising 9 soluble ligands and 33 lateral partners. The fact that uPAR interacts with members of three major families of membrane receptors i.e. G protein-coupled receptors, receptor tyrosine kinases, and integrins implies that the actual number of components constituting the uPAR interacome is extremely high. For example, 156 factors belong to the integrin adhesome. Moreover, in the light of the wide diversity of the components of the uPAR interactome, uPAR appears to be an essential player of major biological systems including the blood coagulation, complement and plasma kallikrein-kinin cascades. This review describes the soluble ligands and lateral partners of the uPAR interactome, the mechanisms regulating uPAR interactions and their proved and/or potential biological functions.
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PMID:The urokinase receptor interactome. 2171 Dec 37

Several components of the urokinase-type plasminogen activator receptor (uPAR)-interactome, including uPAR and its ligand sushi-repeat protein 2, X-linked (SRPX2), are linked to susceptibility to epileptogenesis in animal models and/or humans. Recent evidence indicates that urokinase-type plasminogen activator (uPA), a uPAR ligand with focal proteinase activity in the extracellular matrix, contributes to recovery-enhancing brain plasticity after various epileptogenic insults such as traumatic brain injury (TBI) and status epilepticus. Here, we examined whether deficiency of the uPA-encoding gene Plau augments epileptogenesis after TBI. Traumatic brain injury was induced by controlled cortical impact in the somatosensory cortex of adult male wild-type and Plau-deficient mice. Development of epilepsy and seizure susceptibility were assessed with a 3-week continuous video-electroencephalography monitoring and a pentylenetetrazol test, respectively. Traumatic brain injury-induced cortical or hippocampal pathology did not differ between genotypes. The pentylenetetrazol test revealed increased seizure susceptibility after TBI (p<0.05) in injured mice. Epileptogenesis was not exacerbated, however, in Plau-deficient mice. Taken together, Plau deficiency did not worsen controlled cortical impact-induced brain pathology or epileptogenesis caused by TBI when assessed at chronic timepoints. These data expand previous observations on Plau deficiency in models of status epilepticus and suggest that inhibition of focal extracellular proteinase activity resulting from uPA-uPAR interactions does not modify epileptogenesis after TBI.
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PMID:Epileptogenesis after traumatic brain injury in Plau-deficient mice. 2625 97

Recently it has been found that the urokinase receptor (uPAR) and its ligands - urokinase (uPA) and SRPX2 protein play an important role in the development and functioning of the brain. There is a strong association between uPAR gene polymorphism and autism disorders in humans. Patients with autism, intractable lobe epilepsy, verbal dyspraxia and perisylvian polymicrogyria display significant changes in uPAR expression. Mice, lacking the uPAR gene develop epilepsy and demonstrate abnormal social behavior. uPA and SRPX2 protein, have been shown to be involved in pathological brain conditions such as autism, cognitive deficits and language disorders. Urokinase system that stimulates blood vessel growth as demonstrated before, also plays an important role in the regulation of the nerve growth via matrix remodeling and activation of neurotrophic and angiogenic factors. Moreover, the urokinase system also functions as a guidance system which determines the growth trajectory of the vessels' and nerves' in tissue regeneration. This review summarizes and integrates the results and recent progress in the field of uPAR and its endogenous ligands in brain development and cognitive functions.
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PMID:[PARTICIPATION OF UROKINASE RECEPTOR AND ITS ENDOGENOUS LIGANDS IN BRAIN DEVELOPMENT AND FORMATION OF COGNITIVE FUNCTIONS]. 3019 55