Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The proenzyme single-chain urokinase plasminogen activator (scuPA) more effectively resolved intrapleural loculations in rabbits with tetracycline (TCN)-induced loculation than a range of clinical doses of two-chain uPA (Abbokinase) and demonstrated a trend toward greater efficacy than single-chain tPA (Activase) (Idell S et al., Exp Lung Res 33: 419, 2007.). scuPA more slowly generates durable intrapleural fibrinolytic activity than Abbokinase or Activase, but the interactions of these agents with inhibitors in pleural fluids (PFs) have been poorly understood. PFs from rabbits with TCN-induced pleural injury treated with intrapleural scuPA, its inactive Ser195Ala mutant, Abbokinase, Activase, or vehicle, were analyzed to define the mechanism by which scuPA induces durable fibrinolysis. uPA activity was elevated in PFs of animals treated with scuPA, correlated with the ability to clear pleural loculations, and resisted (70-80%) inhibition by PAI-1. Alpha-macroglobulin (alphaM) but not urokinase receptor complexes immunoprecipitated from PFs of scuPA-treated rabbits retained uPA activity that resists PAI-1 and activates plasminogen. Conversely, little plasminogen activating or enzymatic activity resistant to PAI-1 was detectable in PFs of rabbits treated with Abbokinase or Activase. Consistent with these findings, PAI-1 interacts with scuPA much slower than with Activase or Abbokinase in vitro. An equilibrium between active and inactive scuPA (k(on) = 4.3 h(-1)) limits the rate of its inactivation by PAI-1, favoring formation of complexes with alphaM. These observations define a newly recognized mechanism that promotes durable intrapleural fibrinolysis via formation of alphaM/uPA complexes. These complexes promote uPA-mediated plasminogen activation in scuPA-treated rabbits with TCN-induced pleural injury.
Am J Physiol Lung Cell Mol Physiol 2009 Oct
PMID:Regulation of intrapleural fibrinolysis by urokinase-alpha-macroglobulin complexes in tetracycline-induced pleural injury in rabbits. 1966 76

Rubisco activase functions to promote and maintain the catalytic activity of Rubisco. Studies with the activase-lacking Arabidopsis rca mutant (Salvucci et al. Photosynth Res 7:193-201, 1985; Salvucci et al. Plant Physiol 80:655-659, 1986), antisense activase tobacco, Arabidopsis and Flaveria bidentis plants (Mate et al. Plant Physiol 102:1119-1128, 1993; Eckardt et al. Plant Physiol 113:575-586, 1997; von Caemmerer et al. Plant Physiol 137:747-755, 2005) have shown that photosynthesis at atmospheric levels of CO2 is severely impaired when plants lack activase because Rubisco becomes sequestered in an inactive form. Activase protein has been detected in all plant species, including C3 and C4 plants and green algae (Salvucci et al. Plant Physiol 84:930-936, 1987). Rubisco activase is essential in all these photosynthetic organisms for photosynthesis and plant growth. The physiological importance of Rubisco activase is reinforced by recent studies indicating that it plays a role in the response of photosynthesis to temperature. In this chapter, we describe how to extract and quantify Rubisco activase content in leaf.
Methods Mol Biol 2011
PMID:Quantification of Rubisco activase content in leaf extracts. 2096 Jan 45