scholarly journals Pentamidine Inhibition of Group I Intron Splicing in Candida albicans Correlates with Growth Inhibition

2000 ◽  
Vol 44 (4) ◽  
pp. 958-966 ◽  
Author(s):  
Karl E. Miletti ◽  
Michael J. Leibowitz
Keyword(s):  
Candida Albicans ◽  
Growth Inhibition ◽  
Pneumocystis Carinii ◽  
Group I Intron ◽  
Rrna Genes ◽  
Broth Microdilution ◽  
Reverse Transcription Pcr ◽  
Group I ◽  
Rrna Maturation

ABSTRACT We previously demonstrated that pentamidine, which has been clinically used against Pneumocystis carinii, inhibits in vitro a group I intron ribozyme from that organism. Another fungal pathogen, Candida albicans, also harbors a group I intron ribozyme (Ca.LSU) in the essential rRNA genes in almost half of the clinical isolates analyzed. To determine whether pentamidine inhibits Ca.LSU in vitro and in cells, phylogenetically closely related intron-containing (4-1) and intronless (62-1) strains were studied. Splicing in vitro of the Ca.LSU group I intron ribozyme was completely inhibited by pentamidine at 200 μM. On rich glucose medium, the intron-containing strain was more sensitive to growth inhibition by pentamidine than was the intronless strain, as measured by disk or broth microdilution assays. On rich glycerol medium, they were equally susceptible to pentamidine. At pentamidine levels selectively inhibiting the intron-containing strain (1 μM) in glucose liquid cultures, inhibition of splicing and rRNA maturation was detected by quantitative reverse transcription-PCR within 1 min with a 10- to 15-fold accumulation of precursor rRNA. No comparable effect was seen in the intronless strain. These results correlate the cellular splicing inhibition of Ca.LSU with the growth inhibition of strain 4-1 harboring Ca.LSU. Broth microdilution assays of 13 Candida strains showed that intron-containing strains were generally more susceptible to pentamidine than the intronless strains. Our data suggest that ribozymes found in pathogenic microorganisms but absent in mammals may be targets for antimicrobial therapy.

scholarly journals Activity of Hoechst 33258 against Pneumocystis carinii f. sp. muris, Candida albicans, and Candida dubliniensis

2005 ◽  
Vol 49 (4) ◽  
pp. 1326-1330 ◽  
Author(s):  
Matthew D. Disney ◽  
Ruth Stephenson ◽  
Terry W. Wright ◽  
Constantine G. Haidaris ◽  
Douglas H. Turner ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Nucleic Acids ◽  
Mammalian Cells ◽  
Pneumocystis Carinii ◽  
Candida Dubliniensis ◽  
Group I Introns ◽  
Hoechst 33258 ◽  
Group I ◽  
Self Splicing

ABSTRACT Hoechst 33258 is a compound that binds nucleic acids. We report that Hoechst 33258 exhibits antimicrobial activity against Pneumocystis carinii f. sp. muris in a mouse model for P. carinii pneumonia and against Candida albicans and Candida dubliniensis in vitro. Relative to saline treatment, a 14-day, daily treatment of mice with 37.5 mg of Hoechst 33258/kg of body weight after inoculation with P. carinii reduced by about 100-fold the number of P. carinii organisms detected by either PCR or by microscopy after silver staining. For comparison, treatment based on a dose of 15 to 20 mg of the trimethoprim component in trimethoprim-sulfamethoxazole/kg reduced the number of P. carinii by about fourfold. In vitro inhibition of P. carinii group I intron splicing was observed with a 50% inhibitory concentration (IC50)of 30 μM in 2 or 4 mM Mg2+, suggesting RNA as a possible target. However, Hoechst 33258 inhibits growth of Candida strains with and without group I introns. IC50s ranged from 1 to 9 μM for strains with group I introns and were 12 and 32 μM for two strains without group I introns. These studies demonstrate that compounds that bind fungal nucleic acids have the potential to be developed as new therapeutics for Pneumocystis and possibly other fungi, especially if they could be directed to structures that are not present in mammalian cells, such as self-splicing introns.

Inhibition of In Vitro Splicing of a Group I Intron of Pneumocystis carinii

1994 ◽  
Vol 41 (1) ◽  
pp. 31-38 ◽  
Author(s):  
YONG LIU ◽  
RICHARD R. TIDWELL ◽  
MICHAEL J. LEIBOWITZ
Keyword(s):  
Pneumocystis Carinii ◽  
Group I Intron ◽  
Group I ◽  
In Vitro Splicing

scholarly journals A Unique Group I Intron in Coxiella burnetii Is a Natural Splice Mutant

2009 ◽  
Vol 191 (12) ◽  
pp. 4044-4046 ◽  
Author(s):  
Rahul Raghavan ◽  
Linda D. Hicks ◽  
Michael F. Minnick
Keyword(s):  
Coxiella Burnetii ◽  
Group I Intron ◽  
23S Rrna ◽  
Rrna Gene ◽  
Group I Introns ◽  
Group I ◽  
23S Rrna Gene ◽  
Self Splicing

ABSTRACT Cbu.L1917, a group I intron present in the 23S rRNA gene of Coxiella burnetii, possesses a unique 3′-terminal adenine in place of a conserved guanine. Here, we show that, unlike all other group I introns, Cbu.L1917 utilizes a different cofactor for each splicing step and has a decreased self-splicing rate in vitro.

scholarly journals In vitro activity of a new echinocandin, LY303366, compared with those of amphotericin B and fluconazole against clinical yeast isolates.

1997 ◽  
Vol 41 (5) ◽  
pp. 1156-1157 ◽  
Author(s):  
O Uzun ◽  
S Kocagöz ◽  
Y Cetinkaya ◽  
S Arikan ◽  
S Unal
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method

The in vitro activity of LY303366, a new echinocandin derivative, was evaluated with 191 yeast isolates by a broth microdilution method. The MICs at which 50% of the isolates were inhibited were 0.125 microg/ml for Candida albicans and C. tropicalis, 0.25 microg/ml for C. krusei, C. kefyr, and C. glabrata, and 2.0 microg/ml for C. parapsilosis.

scholarly journals I-PpoI, the Endonuclease Encoded by the Group I Intron PpLSU3, Is Expressed from an RNA Polymerase I Transcript

1998 ◽  
Vol 18 (10) ◽  
pp. 5809-5817 ◽  
Author(s):  
Jue Lin ◽  
Volker M. Vogt
Keyword(s):  
Rna Polymerase ◽  
Homing Endonuclease ◽  
Group I Intron ◽  
Subcellular Fractionation ◽  
Rna Polymerase I ◽  
Rrna Genes ◽  
Temperature Sensitive ◽  
Group I ◽  
Polymerase I ◽  
Mutant Forms

ABSTRACT PpLSU3, a mobile group I intron in the rRNA genes of Physarum polycephalum, also can home into yeast chromosomal ribosomal DNA (rDNA) (D. E. Muscarella and V. M. Vogt, Mol. Cell. Biol. 13:1023–1033, 1993). By integrating PpLSU3 into the rDNA copies of a yeast strain temperature sensitive for RNA polymerase I, we have shown that the I-PpoI homing endonuclease encoded by PpLSU3 is expressed from an RNA polymerase I transcript. We have also developed a method to integrate mutant forms of PpLSU3 as well as theTetrahymena intron TtLSU1 into rDNA, by expressing I-PpoI in trans. Analysis of I-PpoI expression levels in these mutants, along with subcellular fractionation of intron RNA, strongly suggests that the full-length excised intron RNA, but not RNAs that are further cleaved, serves as or gives rise to the mRNA.

scholarly journals Synergistic Activity of Chloroquine with Fluconazole against Fluconazole-Resistant Isolates of Candida Species

2014 ◽  
Vol 59 (2) ◽  
pp. 1365-1369 ◽  
Author(s):  
Yali Li ◽  
Zhe Wan ◽  
Wei Liu ◽  
Ruoyu Li
Keyword(s):  
Candida Albicans ◽  
Synergistic Effect ◽  
Candida Tropicalis ◽  
Candida Krusei ◽  
Synergistic Activity ◽  
Broth Microdilution ◽  
Content Type ◽  
Fluconazole Resistant ◽  
Susceptibility Tests

ABSTRACTThein vitroactivity of chloroquine and the interactions of chloroquine combined with fluconazole against 37Candidaisolates were tested using the broth microdilution, disk diffusion, and Etest susceptibility tests. Synergistic effect was detected with 6 of 9 fluconazole-resistantCandida albicansisolates, withCandida kruseiATCC 6258, and with all 12 fluconazole-resistantCandida tropicalisisolates.

scholarly journals A Self-Splicing Group I Intron in DNA Polymerase Genes of T7-Like Bacteriophages

2004 ◽  
Vol 186 (23) ◽  
pp. 8153-8155 ◽  
Author(s):  
Richard P. Bonocora ◽  
David A. Shub
Keyword(s):  
Dna Polymerase ◽  
Group I Intron ◽  
Group I Introns ◽  
Homing Endonucleases ◽  
Structural Element ◽  
Group I ◽  
Close Relatives ◽  
Self Splicing

ABSTRACT Group I introns are inserted into genes of a wide variety of bacteriophages of gram-positive bacteria. However, among the phages of enteric and other gram-negative proteobacteria, introns have been encountered only in phage T4 and several of its close relatives. Here we report the insertion of a self-splicing group I intron in the coding sequence of the DNA polymerase genes of ΦI and W31, phages that are closely related to T7. The introns belong to subgroup IA2 and both contain an open reading frame, inserted into structural element P6a, encoding a protein belonging to the HNH family of homing endonucleases. The introns splice efficiently in vivo and self-splice in vitro under mild conditions of ionic strength and temperature. We conclude that there is no barrier for maintenance of group I introns in phages of proteobacteria.

5‘ Transcript Replacement in Vitro Catalyzed by a Group I Intron-Derived Ribozyme†

Biochemistry ◽  
2005 ◽  
Vol 44 (21) ◽  
pp. 7796-7804 ◽  
Author(s):  
Rashada C. Alexander ◽  
Dana A. Baum ◽  
Stephen M. Testa
Keyword(s):  
Group I Intron ◽  
Group I
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