Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 7436549

Evaluating promulgated refinery effluent standards using artificial streams.

R A Honig·A L Buikema
View original source ↗Export metadata ↓

Abstract

Two-week tests on an Artificial Refinery MIxture (ARM) were conducted on periphyton communities on glass slides in laboratory streams. ARM components, which are present in "typical" refinery effluents, approximate maximum allowable concentrations as promulgated by the 1977 U.S. Environmental Protection Agency (USEPA) guidelines for refinery effluents. ARM concentrations tested ranged from approximately 0.25 to 5 times full strength. The nontaxonomic structural parameters--ash-free dry weight, chlorophyll a, and ATP--indicated that ARM concentrations of 1 to 5X stimulated periphyton colonization rates. ARM concentrations of 0.25 to 5X caused a shift in dominant periphytic algae from diatoms in reference streams to green algae in dosed streams; this resulted in higher pH levels in reference streams, apparently related to photosynthetic activity. Changes in nontaxonomic structural parameters of slides precolonized with periphyton were not sensitive water quality indicators. Dry weight was not a useful biomass indicator due to high levels of suspended solids in ARM. The promulgated 1977 guidelines may be adequate to maintain nontaxonomic structural integrity of periphyton communities, while the 1983 guidelines appear to be adequate to maintain taxonomic integrity.

Explore related subjects

Adenosine TriphosphateAnimalsChemical PhenomenaChemistry, PhysicalChlorophyllEukaryotaFresh WaterHydrogen-Ion ConcentrationIndustrial WasteSnailsWater SupplyJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R A Honig, A L Buikema. 1980. Evaluating promulgated refinery effluent standards using artificial streams.. https://doi.org/10.1007/bf01056940

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2022

The human mitochondrial genome contains a second light strand promoter.

The human mitochondrial genome must be replicated and expressed in a timely manner to maintain energy metabolism and supply cells with adequate levels of adenosine triphosphate. Central to this process is the idea that replication primers and gene products both arise via transcription from a single light strand promoter (LSP) such that primer formation can influence gene expression, with no consensus as to how this is regulated. Here, we report the discovery of a second light strand promoter (LSP2) in humans, with features characteristic of a bona fide mitochondrial promoter. We propose that the position of LSP2 on the mitochondrial genome allows replication and gene expression to be orchestrated from two distinct sites, which expands our long-held understanding of mitochondrial gene expression in humans.

Adenosine Triphosphate↗
PubMed2021

GCN2 kinase activation by ATP-competitive kinase inhibitors.

Small-molecule kinase inhibitors represent a major group of cancer therapeutics, but tumor responses are often incomplete. To identify pathways that modulate kinase inhibitor response, we conducted a genome-wide knockout (KO) screen in glioblastoma cells treated with the pan-ErbB inhibitor neratinib. Loss of general control nonderepressible 2 (GCN2) kinase rendered cells resistant to neratinib, whereas depletion of the GADD34 phosphatase increased neratinib sensitivity. Loss of GCN2 conferred neratinib resistance by preventing binding and activation of GCN2 by neratinib. Several other Food and Drug Administration (FDA)-approved inhibitors, such erlotinib and sunitinib, also bound and activated GCN2. Our results highlight the utility of genome-wide functional screens to uncover novel mechanisms of drug action and document the role of the integrated stress response (ISR) in modulating the response to inhibitors of oncogenic kinases.

Adenosine Triphosphate↗
PubMed2007

Protein phosphorylation corrects the folding defect of the neuroblastoma (S120G) mutant of human nucleoside diphosphate kinase A/Nm23-H1.

Human nucleoside diphosphate (NDP) kinase A is a 'house-keeping' enzyme essential for the synthesis of nonadenine nucleoside (and deoxynucleoside) 5'-triphosphate. It is involved in complex cellular regulatory functions including the control of metastatic tumour dissemination. The mutation S120G has been identified in high-grade neuroblastomas. We have shown previously that this mutant has a folding defect: the urea-denatured protein could not refold in vitro. A molten globule folding intermediate accumulated, whereas the wild-type protein folded and associated into active hexamers. In the present study, we report that autophosphorylation of the protein corrected the folding defect. The phosphorylated S120G mutant NDP kinase, either autophosphorylated with ATP as donor, or chemically prosphorylated by phosphoramidate, refolded and associated quickly with high yield. Nucleotide binding had only a small effect. ADP and the non-hydrolysable ATP analogue 5'-adenyly-limido-diphosphate did not promote refolding. ATP-promoted refolding was strongly inhibited by ADP, indicating protein dephosphorylation. Our findings explain why the mutant enzyme is produced in mammalian cells and in Escherichia coli in a soluble form and is active, despite the folding defect of the S120G mutant observed in vitro. We generated an inactive mutant kinase by replacing the essential active-site histidine residue at position 118 with an asparagine residue, which abrogates the autophosphorylation. The double mutant H118N/S120G was expressed in inclusion bodies in E. coli. Its renaturation stops at a folding intermediate and cannot be reactivated by ATP in vitro. The transfection of cells with this double mutant might be a good model to study the cellular effects of folding intermediates.

Adenosine Triphosphate↗