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Query: UNIPROT:P06889 (Mol)
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By genetic analysis we examined UV mutagenesis of the Escherichia coli glyU gene. When carried by M13 phage mp9, glyU is subject to induced UV mutagenesis which is dependent on the umuC+ and recF+ genes. When carried by M13 phage mp8, glyU is not subject to induced UV mutagenesis. This difference is correlated with the nature of the target nucleotides: CTC in the mp9 derivative and GAG in the mp8 derivative. Thus, we conclude that the induced (umuC and recF dependent) mutagenesis is locally targeted on pyrimidine cyclobutane or 6-4 dimers. glyU carried by M13 is equally subject to uninduced UV mutagenesis whether carried by mp8 or mp9. This uninduced mutagenesis is independent of the umuC+, recF+ and recA+ genes and we hypothesize that it is regionally targeted on pyrimidine cyclobutane or 6-4 dimers in the vicinity of the target CTC and GAG nucleotides. The role of recF in UV mutagenesis was tested in two ways. First, mutagenesis of glyU carried by M13 mp9 in a recA730 genetic background was found to be recF dependent. Because recA730 renders induced UV mutagenesis partially constitutive, we conclude that the RecF product plays a direct role in UV mutagenesis rather than, or in addition to, any indirect regulatory role it may play. Second, UV mutagenesis of E. coli chromosomal glyU was found to be recF independent while UV mutagenesis of M13-bourne glyU was recF dependent. We conclude that the mechanism of induced UV mutagenesis of the E. coli chromosome is at least partly different from that of M13 phage and we discuss the biochemical basis for such a difference.
Mol Gen Genet 1987 Apr
PMID:Genetic analysis of UV mutagenesis of the Escherichia coli glyU gene. 243 81

In this study we report on some lines of ongoing research performed in our laboratory, in relation to the increased expression of FcR on tumor cells, as well as on cells present in the tumor-bearing host, and its possible role in tumor progression. In a previous study we have shown that a Polyoma virus (PyV)-induced anaplastic carcinoma (SEYF-a tumor) contained an FcR-expressing subpopulation of tumorigenic cells. We tested the effect of in vivo passaging of FcR-expressing and of non-FcR-expressing sub-populations of SEYF-a tumor cells on the expression of FcR, as revealed by the ability of these cells to bind the 2.4G2 monoclonal antibody, which is directed against mouse Fc gamma 2b/gamma 1R. It was found that upon in vivo passaging these two sub-populations became practically identical in their ability to bind anti-Fc gamma R antibody. On the other hand, in vitro passaging of FcR-expressing SEYF-a cells resulted in a gradual decrease in the expression of Fc gamma R. These results, indicating that the expression of Fc gamma R on tumor cells, per se, is dependent on a factor present in the in vivo environment were confirmed using 3T3 cells transformed in vitro by PyV (C) and forming tumors at first injection to mice (CTC). C cultures of various clones did not express Fc gamma R, while CTC cultures (cultures from tumors) became positive. We also detected an increase in the level of a soluble form of Fc gamma 2b/gamma 1R in the circulation of mice bearing PyV induced tumors. This increase paralleled the appearance of palpable tumors. A similar pattern of increase was observed in mice inoculated with the c-H-ras transformed tumorigenic clone 8/F/5, but not in mice inoculated with non-tumorigenic 3T3 cells. Data published by us show that metastatic breast cancer patients had significantly elevated Fc gamma R levels on their peripheral blood mononuclear cells (PBMC). Experiments presented here indicate a direct correlation between increased Fc gamma R levels on PBMC and tumor mass in colon, ovary and lung metastatic carcinoma patients. The possibility that malignantly transformed cells have the potential to cause proliferation of Fc gamma R expressing T cells was tested. It was found that extract derived from r-H-ras transformed 3T3 cells triggers the proliferation of a T cell hybridoma expressing Fc gamma R.
Mol Immunol 1988 Nov
PMID:Increased expression of Fc gamma receptor in cancer patients and tumor bearing mice. 285 35

A 25-kb DNA region, previously cloned from Pseudomonas syringae pv. syringae 61 in cosmid pHIR11, enables nonpathogenic bacteria such as Pseudomonas fluorescens and Escherichia coli to elicit the hypersensitive response (HR) in tobacco (Nicotiana tabacum). hrmA is located within this region, adjacent to a conserved cluster of hrp genes, and is essential for nonpathogens to elicit the HR. DNA sequence analysis suggested that hrmA was the second of two genes in an operon and was preceded by an open reading frame (ORF), ORF1, which is predicted to encode a 10.9-kDa protein. DNA gel blot analysis revealed that sequences hybridizing with a DNA fragment internal to hrmA were absent from P. syringae pv. syringae B728a, P. syringae pv. tabaci 11528, and P. syringae pv. glycinea race 4 U1, but present in P. syringae pv. tomato DC3000. A 2.4-kb BamHI-AvrII fragment carrying hrmA, ORF1, and native regulatory sequences was subcloned into broad-host-range vector pDSK519 and electroporated into P. syringae pv. syringae B728a and P. syringae pv. tabaci 11528. The presence of the hrmA locus had no apparent effect on the ability of P. syringae pv. syringae B728a to cause brown spot of bean, but it caused P. syringae pv. tabaci 11528 to elicit the defense-associated HR rather than disease in N. tabacum cvs. Xanthi N and Xanthi NC and N. clevelandii. Furthermore, N. debeyii, N. glutinosa, N. rustica, and N. tabacum cvs. Petit Havana and Samsun responded with the HR to P. fluorescens(pHIR11). In contrast, N. benthamiana-P. syringae pv. tabaci interactions were unaffected by the presence of HrmA, and P. fluorescens(pHIR11) did not elicit the HR in N. benthamiana. The hrmA ORF was subcloned into pFLAG-CTC, which expressed HrmA with a C-terminal FLAG synthetic epitope fusion. Escherichia coli MC4100 cells carrying the functional hrp cluster and the hrmA-FLAG derivative secreted the HrpZ harpin, but not HrmA-FLAG, to the medium, as indicated by immunoblot analysis with M2 anti-FLAG and polyclonal anti-HrpZ antibodies. The hrmA ORF was also subcloned into plant expression vector pFF19 and then biolistically delivered, along with pFF19G (expressing beta-glucuronidase), into suspension-cultured tobacco cells. Histochemical staining 24 h later revealed substantial beta-glucuronidase activity in cells receiving pFF19G and pFF19 but not in those receiving pFF19G and pFF19-HrmA. Thus, internal production of HrmA was deleterious to tobacco cells.
Mol Plant Microbe Interact 1997 Jul
PMID:Evidence that the Pseudomonas syringae pv. syringae hrp-linked hrmA gene encodes an Avr-like protein that acts in an hrp-dependent manner within tobacco cells. 920 63

The allotype of human immunoglobulin kappa light chain constant region gene (IGKC) has been identified by the serological assay or DNA typing method. The three allotypes Km*1, Km*1,2 and Km*3 have amino acid substitutions at positions of codons 153 and 191 in the kappa light chain constant region. The Km allotypes were designated as follows: Km*1 has valine (GTC) at position 153 and leucine (CTC) at 191; Km*1,2 has Ala153 (GCC) and Leu191 (CTC); Km*3 has Ala153 (GCC) and Val191 (GTC). In this study, polymerase chain reaction-allele specific oligonucleotide (PCR-ASO) was used to provide a specific allelic typing system for the IGKC gene in 213 unrelated Koreans. For Km genotyping, the IGKC coding regions plus 35 bp of the 3' untranslated regions were amplified with specific primers. Amplified genes were hybridized with Km ASO probes at positions of codons 153 and 191 and were detected using a colorimetric detection method. The frequencies of Km*1,2/Km*1,2, Km*1,2/Km*3, and Km*3/Km*3 were 17.8% (n=38), 51.7% (n=110), and 30.5% (n=65), respectively. The estimated allele frequencies for Km*1,2 and Km*3 were 0.44 and 0.56, respectively. The homozygote or the heterozygote of Km*1 was not observed in this study. The PCR-ASO method distinguished the alleles Km*3, Km*1,2, and Km*1 and also distinguished the homozygote from heterozygote. Km frequencies vary significantly among various populations. Km*3 in Koreans was very similar to those observed in northern Chinese, Japanese, and the native people of British Columbia. It was lower than that reported in Caucasian, Indian, or southern Chinese.
Mol Cells 1997 Aug 31
PMID:Km genotyping using polymerase chain reaction-allele specific oligonucleotide in Koreans. 933 90

The base pair substitution mutational profiles induced by the heterocyclic amine cooked food mutagens PhlP and IQ in Salmonella typhimurium strains TA100 and TA1535 were determined by colony hybridization analysis. Both PhlP and IQ induced predominantly GC-->TA transversions in strain TA100 (rfa,delta uvrB/pKM101) with a pronounced preference for the second codon position (CCC--> CAC; 72% of total). PhlP also reverted strain TA1535 (rfa, delta uvrB) efficiently at concentrations similar to those required for strain TA100. In contrast to the PhlP-induced mutational profile observed in strain TA100, in strain TA1535 PhlP induced exclusively GC-->AT transitions at the second codon position (CCC-->CTC; 96-99% of total). Base substitution mutagenesis induced by heterocyclic amines related to PhlP is generally SOS-dependent, requiring the presence of plasmid pKM101 in Salmonella hisG46 strains. Thus, the SOS dependent reversion of S. typhimurium strain TA100 probably reflects error-prone lesion bypass at the major PhlP- guanosine adduct at the C-8 position. The GC-->AT transition mutations induced by PhlP in strain TA1535 appear to be SOS-independent, however, suggesting that these mutations may arise from the formation of PhlP-DNA adducts other than the replication-blocking C8-dG lesion.
Environ Mol Mutagen 1998
PMID:Specificity of base substitution mutations induced by the dietary carcinogens 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhlP) and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) in Salmonella. 965 41

We recently described an untranslated CTG expansion that causes a previously undescribed form of spinocerebellar ataxia (SCA8). The SCA8 CTG repeat is preceded by a polymorphic but stable CTA tract, with the configuration (CTA)(1-21)(CTG)(n). The CTG portion of the repeat is elongated on pathogenic alleles, which nearly always change in size when transmitted from generation to generation. To better understand the reduced penetrance and maternal penetrance bias associated with SCA8 we analyzed the sequence configurations and instability patterns of the CTG repeat in affected and unaffected family members. In contrast to other triplet repeat diseases, expanded alleles found in affected SCA8 individuals can have either a pure uninterrupted CTG repeat tract or an allele with one or more CCG, CTA, CTC, CCA or CTT interruptions. Surprisingly, we found six different sequence configurations of the CTG repeat on expanded alleles in a seven generation family. In two instances duplication of CCG interruptions occurred over a single generation and in other instances duplications that had occurred in different branches of the family could be inferred. We also evaluated SCA8 instability in sperm samples from individuals with expansions ranging in size from 80 to 800 repeats in blood. Surprisingly the SCA8 repeat tract in sperm underwent contractions, with nearly all of the resulting expanded alleles having repeat lengths of <100 CTGs, a size that is not often associated with disease. These en masse repeat contractions in sperm likely underlie the reduced penetrance associated with paternal transmission.
Hum Mol Genet 2000 Sep 01
PMID:SCA8 CTG repeat: en masse contractions in sperm and intergenerational sequence changes may play a role in reduced penetrance. 1095 51

Mutations of the Smad2 and Smad4 genes, identified as mediators of the transforming growth factor-beta pathway, were investigated in lung adenocarcinomas induced by N-nitrosobis(2-hydroxypropyl)amine (BHP) in rats. Male Wistar rats, 6 wk old, were given 2000 ppm BHP in their drinking water for 12 wk and maintained without additional treatment until killed at week 25. Total RNA was extracted from 12 adenocarcinomas, and mutations in Smad2 and Smad4 were investigated by reverse transcription-polymerase chain reaction restriction single-strand conformation polymorphism analysis followed by sequencing analysis. In Smad2, single adenocarcinomas showed a GGC to GAC (Gly to Asp) transition at codon 100 and an AAG to GAG (Lys to Glu) transition at codon 383. In Smad4, one adenocarcinoma exhibited a TTC to CTC (Phe to Leu) transition at codon 214. These results suggest that mutations of Smad2 and Smad4 may play roles in a limited fraction of lung adenocarcinomas induced by BHP in rats.
Mol Carcinog 2000 Oct
PMID:Mutations of the Smad2 and Smad4 genes in lung adenocarcinomas induced by N-nitrosobis(2-hydroxypropyl)amine in rats. 1107 5

Calcium level in organelles of the slime mold Physarum polycephalum was monitored by chlortetracycline, a low-affinity calcium indicator. It was found that 2,5'-di(tertbutyl)-1,4,-benzohydroquinone (BHQ) at a concentration of 100 microM, but not the highly specific inhibitor of sarco-endoplasmic reticulum Ca2+-ATPase (SERCA), thapsigargin (1-10 microM), elicited calcium release from the CTC-stained intracellular calcium pool. Ionomycin also caused a calcium release (23.7+/-5.1%), which was less than that induced by BHQ (30.1+/-6.0%). Procaine (10 mM), a blocker of ryanodine receptor, completely abolished the responses to BHQ and ionomycin. Another blocker, ryanodine (100 microM), only slightly diminished the responses to ionomycin and BHQ. Apparently, BHQ and ionomycin acting as a Ca2+-ATPase inhibitor and an ionophore, respectively, elicit an increase in [Ca2+]i, which in turn triggers a calcium-induced calcium release (CICR) via the ryanodine receptor. Caffeine, an activator of ryanodine receptor, at a concentration of 25-50 mM produced a Ca2+-release (5.6-16.0%), which was not similar in magnitude to CICR. The response to 25 mM caffeine was only moderately inhibited by 25 mM procaine, and almost completely abolished by 50 mM procaine and 100 microM ryanodine.
Comp Biochem Physiol A Mol Integr Physiol 2001 Feb
PMID:Ionomycin and 2,5'-di(tertbutyl)-1,4,-benzohydroquinone elicit Ca2+-induced Ca2+ release from intracellular pools in Physarum polycephalum. 1122 89

Asian elephants are not self-sustaining in captivity. The main reasons for this phenomenon are a low birth rate, an aging population, and poor calf-rearing. Therefore, it is essential that reproductive rates had to be improved and there is need for rapid quantitative measures to monitor reproductive functions focussing on estrous detection and the prediction of the period of parturition. The objective of this study was to develop a method which combines headspace solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) for analyses of 5alpha-androst-2-en-17beta-ol and -17-one to prognose estrous and to predict the period of parturition. SPME was carried out with a CTC Combi Pal system. The course of the luteal phase-specific substance 5alpha-androst-2-en-17beta-ol and -17-one followed a cyclic pattern in which the follicular and luteal phases could be clearly distinguished (mean estrous cycle length, 15+/-1.4 weeks). Based on daily urine samples, estrous prognosis might be possibly based on the initial 5alpha-androst-2-en-17beta-o1 increase at the end of the follicular phase. Parturition prognosis was performed in three elephant cows based on the 5alpha-androst-2-en-17beta-o1 drop to baseline levels 5-4 days prior parturition. Experiments revealed that 5alpha-androst-3alpha-ol-17-one and probably 5alpha-androst-3alpha-ol-17beta-ol are generated from sulfate conjugates by a thermal process.
J Steroid Biochem Mol Biol 2003 Feb
PMID:Headspace solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) for the determination of 5alpha-androst-2-en-17-one and -17beta-ol in the female Asian elephant: application for reproductive monitoring and prediction of parturition. 1271 Oct 27

Electrocatalytic oxidation of the oligonucleotide 5'- GAA GAG GTT TTT CCT CTT CTT TTT CTT CTC C (TS) by Ru(bpy)(3)(2+) was studied by cyclic voltammetry. This oligonucleotide forms either an intramolecular triplex, hairpin, or single strand, depending on the pH (Plum, G. E.; Breslauer, K. J. J. Mol. Biol. 1995, 248, 679-695). In the triplex form, the guanine doublet in TS is buried inside the folded structure, and as such is less susceptible to oxidation by electrogenerated Ru(bpy)(3)(3+). Digital simulations of the catalytic voltammograms gave a rate constant of 3.5 +/- 0.2 x 10(2) M(-1) s(-1) for oxidation of the triplex form, while oxidation of the duplex and single-stranded forms occurred with much faster rate constants of (3.5-9.1) x 10(4) M(-1) s(-1). Experiments using a truncated form of TS that lacked the third strand of the triplex were consistent with these measurements. The Ru(bpy)(3)(3+) complex was also generated by photolyzing Ru(bpy)(3)(2+) in the presence of Fe(CN)(6)(3-). This reaction produced strand scission following piperidine treatment, which was visualized using high-resolution gel electrophoresis. These experiments showed decreased reactivity for the triplex form, and also gave an unusual reversal of a common selectivity for the 5'-G of GG doublets generally seen in B-form DNA. This reversal was ascribed to strain caused by the location of the GG doublet adjacent to the hairpin loop.
 ...
PMID:Electrochemical determination of triple helices: electrocatalytic oxidation of guanine in an intramolecular triplex. 1528 84


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