Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inhalation of quartz particles is associated with a variety of adverse lung effects. Since particle surface is considered to be crucial for particle pathogenicity, we investigated the influence of quartz surface properties on lung burden, inflammation (bronchoalveolar lavage cells), and cytotoxicity (protein, lactate dehydrogenase, beta-glucuronidase) 90 days after a single intratracheal instillation of 2 mg DQ12 into rats. The role of particle surface characteristics was investigated by comparative investigation of native versus surface-modified quartz, using polyvinylpyridine N-oxide (PVNO) or aluminum lactate (AL) coating. Uptake and subcellular localization of quartz samples as well as tumor necrosis factor (TNF)-alpha release were determined using NR8383 rat alveolar macrophages. Surface modification of quartz particles resulted in marked in vivo and in vitro changes. Compared to native quartz, modified quartz samples showed lower lung burden at 90 days, as well as decreased inflammatory and cytotoxic responses. Coating with polyvinylpyridine N-oxide (PVNO) appeared to be more effective than aluminium lactate (AL). PVNO-coating of quartz also resulted in an enhanced particle uptake by macrophages up to 24 h, whereas AL coating caused a transient reduction of quartz uptake at 2 h. At 24 h differences with the native quartz were absent. Subcellular localization of quartz particles was not affected by surface modifications. However, surface modification resulted in a reduced release of TNF-alpha. In conclusion, surface properties of quartz particles appear to be crucial for rate and extent of in vitro particle uptake in macrophages. Our in vivo findings also indicate that quartz surface properties may affect clearance kinetics. Particle surface-specific interactions between quartz and macrophages may therefore play a major role in the pulmonary pathogenicity of quartz.
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PMID:Surface-dependent quartz uptake by macrophages: potential role in pulmonary inflammation and lung clearance. 1788 49

ATP-binding cassette (ABC) transporters represent a large family in plants, but the functions of most of these transporters are unknown. Here we report a gene, AtSTAR1, only encoding an ATP-binding domain of a bacterial-type ABC transporter in Arabidopsis (Arabidopsis thaliana). AtSTAR1 is an ortholog of rice (Oryza sativa) OsSTAR1, which has been implicated in aluminum (Al) tolerance. Knockout of AtSTAR1 resulted in increased sensitivity to Al and earlier flowering. Unlike OsSTAR1, AtSTAR1 was expressed in both the roots and shoots and its expression was not induced by Al or other stresses. Investigation of tissue-specific localization of AtSTAR1 through beta-glucuronidase fusion revealed that AtSTAR1 was predominantly expressed at outer cell layers of root tips and developing leaves, whose localization is also different from those of OsSTAR1. However, introduction of OsSTAR1 into atstar1 mutant rescued the sensitivity of atstar1 to Al, indicating that AtSTAR1 has a similar function as OsSTAR1. Furthermore, we found that AtSTAR1 may interact with ALS3, a transmembrane-binding domain in Arabidopsis to form a complex because introduction of OsSTAR1, a functional substitute of AtSTAR1, into als3 mutant resulted in the loss of OsSTAR1 protein. All these findings indicate that AtSTAR1 is involved in the basic detoxification of Al in Arabidopsis.
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PMID:Knockout of a bacterial-type ATP-binding cassette transporter gene, AtSTAR1, results in increased aluminum sensitivity in Arabidopsis. 2049 40


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