@article {38143,
	title = {Carbonic anhydrase III: the phosphatase activity is extrinsic},
	journal = {Archives of biochemistry and biophysicsArchives of biochemistry and biophysics},
	volume = {377},
	year = {2000},
	note = {http://www.ncbi.nlm.nih.gov/pubmed/10845711?dopt=Abstract},
	type = {10.1006/abbi.2000.1793},
	abstract = {The carbonic anhydrases reversibly hydrate carbon dioxide to yield bicarbonate and hydrogen ion. They have a variety of physiological functions, although the specific roles of each of the 10 known isozymes are unclear. Carbonic anhydrase isozyme III is particularly rich in skeletal muscle and adipocytes, and it is unique among the isozymes in also exhibiting phosphatase activity. Previously published studies provided evidence that the phosphatase activity was intrinsic to carbonic anhydrase III, that it had specificity for tyrosine phosphate, and that activity was regulated by reversible glutathionylation of cysteine186. To study the mechanism of this phosphatase, we cloned and expressed the rat liver carbonic anhydrase III. The purified recombinant had the same specific activity as the carbonic anhydrase purified from rat liver, but it had virtually no phosphatase activity. We attempted to identify an activator of the phosphatase in rat liver and found a protein of approximately 14 kDa, the amount of which correlated with the phosphatase activity of the carbonic anhydrase III fractions. It was identified as liver fatty acid binding protein, which was then purified to test for activity as an activator of the phosphatase and for protein-protein interaction, but neither binding nor activation could be demonstrated. Immunoprecipitation experiments established that carbonic anhydrase III could be separated from the phosphatase activity. Finally, adding additional purification steps completely separated the phosphatase activity from the carbonic anhydrase activity. We conclude that the phosphatase activity previously considered to be intrinsic to carbonic anhydrase III is actually extrinsic. Thus, this isozyme exhibits only the carbon dioxide hydratase and esterase activities characteristic of the other mammalian isozymes, and the phosphatase previously shown to be activated by glutathionylation is not carbonic anhydrase III.},
	keywords = {Animals, Carbonic Anhydrases, Chromatography, High Pressure Liquid, Cloning, Molecular, Enzyme Activation, Glutathione, Kinetics, Liver, Male, Muscles, Phosphoric Monoester Hydrolases, Precipitin Tests, Rabbits, Rats, Rats, Inbred F344, Recombinant Proteins, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Time factors},
	author = {Kim, G. and J. Selengut and Levine, R. L.}
}
@article {49691,
	title = {Expanding the definition of informational suppression.},
	journal = {Trends Genet},
	volume = {16},
	year = {2000},
	month = {2000 Apr},
	pages = {157},
	keywords = {Animals, DNA-Binding Proteins, Drosophila Proteins, Nuclear Proteins, Recombinant Proteins, Repressor Proteins, Suppression, Genetic, Transcription Factors},
	issn = {0168-9525},
	author = {Mount, S M and Anderson, P}
}
@article {49698,
	title = {Suppressor U1 snRNAs in Drosophila.},
	journal = {Genetics},
	volume = {138},
	year = {1994},
	month = {1994 Oct},
	pages = {365-78},
	abstract = {<p>Although the role of U1 small nuclear RNAs (snRNAs) in 5{\textquoteright} splice site recognition is well established, suppressor U1 snRNAs active in intact multicellular animals have been lacking. Here we describe suppression of a 5{\textquoteright} splice site mutation in the Drosophila melanogaster white gene (wDR18) by compensatory changes in U1 snRNA. Mutation of positions -1 and +6 of the 5{\textquoteright} splice site of the second intron (ACG[GTGAGT to ACC]GTGAGC) results in the accumulation of RNA retaining this 74-nucleotide intron in both transfected cells and transgenic flies. U1-3G, a suppressor U1 snRNA which restores base-pairing at position +6 of the mutant intron, increases the ratio of spliced to unspliced wDR18 RNA up to fivefold in transfected Schneider cells and increases eye pigmentation in wDR18 flies. U1-9G, which targets position -1, suppresses wDR18 in transfected cells less well. U1-3G,9G has the same effect as U1-3G although it accumulates to lower levels. Suppression of wDR18 has revealed that the U1b embryonic variant (G134 to U) is active in Schneider cells and pupal eye discs. However, the combination of 9G with 134U leads to reduced accumulation of both U1b-9G and U1b-3G,9G, possibly because nucleotides 9 and 134 both participate in a potential long-range intramolecular base-pairing interaction. High levels of functional U1-3G suppressor reduce both viability and fertility in transformed flies. These results show that, despite the difficulties inherent in stably altering splice site selection in multicellular organisms, it is possible to obtain suppressor U1 snRNAs in flies.</p>},
	keywords = {Alternative Splicing, Animals, Base Sequence, Cell Line, Cell Nucleus, DNA Primers, Drosophila melanogaster, Female, Genes, Suppressor, Genetic Variation, GENOTYPE, Introns, Male, Molecular Sequence Data, Mutagenesis, Site-Directed, Nucleic Acid Conformation, Oligodeoxyribonucleotides, PHENOTYPE, Recombinant Proteins, Ribonucleoprotein, U1 Small Nuclear, RNA, Small Nuclear, Transfection, Transformation, Genetic},
	issn = {0016-6731},
	author = {Lo, P C and Roy, D and Mount, S M}
}
