scholarly journals Lipase 8 Affects the Pathogenesis of Candida albicans

2007 ◽  
Vol 75 (10) ◽  
pp. 4710-4718 ◽  
Author(s):  
Attila Gácser ◽  
Frank Stehr ◽  
Cathrin Kröger ◽  
László Kredics ◽  
Wilhelm Schäfer ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Open Reading Frame ◽  
Infection Model ◽  
Reading Frame ◽  
Reverse Transcription Pcr ◽  
Knockout Mutants ◽  
Important Virulence Factor ◽  
Actin Promoter ◽  
Disruption Method

ABSTRACT The production of lipases can affect microbial fitness and virulence. We examined the role of the lipase 8 (LIP8) gene in the virulence of Candida albicans by constructing Δlip8 strains by the URA-blaster disruption method. Reverse transcription-PCR experiments demonstrated the absence of LIP8 expression in the homozygous knockout mutants. Reconstituted strains and overexpression mutants were generated by introducing a LIP8 open reading frame under control of a constitutive actin promoter. Knockout mutants produced more mycelium, particularly at higher temperatures and pH ≥7. Diminished LIP8 expression resulted in reduced growth in lipid-containing media. Mutants deficient in the LIP8 gene were significantly less virulent in a murine intravenous infection model. The results clearly indicate that Lip8p is an important virulence factor of C. albicans.

scholarly journals One of the tightly clustered genes of the mouse surfeit locus is a highly expressed member of a multigene family whose other members are predominantly processed pseudogenes.

1988 ◽  
Vol 8 (9) ◽  
pp. 3898-3905 ◽  
Author(s):  
C Huxley ◽  
T Williams ◽  
M Fried
Keyword(s):  
Multigene Family ◽  
Open Reading Frame ◽  
The Other ◽  
Base Pairs ◽  
Regulation Of Expression ◽  
Reading Frame ◽  
Processed Pseudogenes ◽  
Dna Fragment ◽  
Basic Polypeptide

The mouse surfeit locus is unusual in that it contains a number of closely clustered genes (Surf-1, -2, and -4) that alternate in their direction of transcription (T. Williams, J. Yon, C. Huxley, and M. Fried, Proc. Natl. Acad. Sci. USA 85:3527-3530, 1988). The heterogeneous 5' ends of Surf-1 and Surf-2 are separated by 15 to 73 base pairs (bp), and the 3' ends of Surf-2 and Surf-4 overlap by 133 bp (T. Williams and M. Fried, Mol. Cell. Biol. 6:4558-4569, 1986; T. Williams and M. Fried, Nature (London) 322:275-279, 1986). A fourth gene in this locus, Surf-3, which is a member of a multigene family, has been identified. The poly(A) addition site of Surf-3 lies only 70 bp from the poly(A) addition site of Surf-1. Transcription of Surf-3 has been studied in the absence of the other members of its multigene family after transfection of a cloned genomic mouse DNA fragment, containing the Surf-3 gene, into heterologous monkey cells. Surf-3 specifies a highly expressed 1.0-kilobase mRNA that contains a long open reading frame of 266 amino acids, which would encode a highly basic polypeptide (23% Arg plus Lys). The other members of the Surf-3 multigene family are predominantly, if not entirely, intronless pseudogenes with the hallmarks of being generated by reverse transcription. The role of the very tight clustering on regulation of expression of the genes in the surfeit locus is discussed.

scholarly journals Role of a Cytotoxic-T-Lymphocyte Epitope-Defined, Alternative gag Open Reading Frame in the Pathogenesis of a Murine Retrovirus-Induced Immunodeficiency Syndrome

2005 ◽  
Vol 79 (7) ◽  
pp. 4308-4315 ◽  
Author(s):  
Arti Gaur ◽  
William R. Green
Keyword(s):  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Leukemia Virus ◽  
Protein S ◽  
Initiation Site ◽  
Open Reading Frame ◽  
Reading Frame ◽  
Ctl Epitope ◽  
Immunodeficiency Syndrome

ABSTRACT LP-BM5 murine leukemia virus-infected C57BL/6 mice develop profound immunodeficiency and B-cell lymphomas. The LP-BM5 complex contains a mixture of defective (BM5def) and replication-competent helper viruses among which BM5def is the primary causative agent of disease. The BM5def primary open reading frame (ORF1) encodes the single gag precursor protein (Pr60 gag ). Our lab has recently demonstrated that a novel immunodominant cytotoxic-T-lymphocyte (CTL) epitope (SYNTGRFPPL) is expressed from a +1-nucleotide translational open reading frame of BM5def during the course of normal retrovirus expression. The SYNTGRFPPL CTL epitope may be generated from either of two initiation methionines present, ORF2a or ORF2b, located downstream of the ORF1 initiation site. This study investigates the role(s) of the alternative ORF2-derived gag protein(s) of BM5def in viral pathogenesis. We have examined the disease-inducing capabilities of mutant viruses in which the translational potential of either the initiating ORF2a or ORF2b AUG has been disrupted. Although these mutated viruses are capable of wild-type ORF1 expression, they are unable to induce disease. Our data strongly suggest the existence of a novel ORF2 product(s) that is required for LP-BM5-induced pathogenesis and have potentially broad implications for other retroviral diseases.

scholarly journals Enhancement of Secretion and Extracellular Stability of Staphylokinase in Bacillus subtilis bywprA Gene Disruption

2000 ◽  
Vol 66 (2) ◽  
pp. 476-480 ◽  
Author(s):  
Sang Jun Lee ◽  
Dong Min Kim ◽  
Kwang Hee Bae ◽  
Si Myung Byun ◽  
Jae Hoon Chung
Keyword(s):  
Bacillus Subtilis ◽  
Gene Disruption ◽  
Therapeutic Potential ◽  
Signal Sequence ◽  
Open Reading Frame ◽  
Expression Plasmid ◽  
Reading Frame ◽  
Extracellular Milieu ◽  
Foreign Proteins

ABSTRACT Staphylokinase (SAK), a polypeptide secreted byStaphylococcus aureus, is a plasminogen activator with a therapeutic potential in thrombosis diseases. A Bacillus subtilis strain which is multiply deficient in exoproteases was transformed by an expression plasmid carrying a promoter and a signal sequence of subtilisin fused in frame with the sak open reading frame. However, the amount of SAK secretion was marginal (45 mg/liter). In contrast, disruption of the wprA gene, which encodes a subtilisin-type protease, strongly promoted the production of SAK in the stationary phase (181 mg/liter). In addition, the extracellular stability of mature SAK was dramatically enhanced. These data indicate a significant role of the wprA gene product in degrading foreign proteins, both during secretion and in the extracellular milieu.

Controlled atmospheres and sugar can delay malate synthase gene expression during asparagus senescence

2002 ◽  
Vol 29 (9) ◽  
pp. 1045 ◽  
Author(s):  
Simon A. Coupe ◽  
Ben K. Sinclair ◽  
Sheryl D. Somerfield ◽  
Paul L. Hurst
Keyword(s):  
Gene Expression ◽  
Single Gene ◽  
Malate Synthase ◽  
Open Reading Frame ◽  
Asparagus Officinalis ◽  
High Identity ◽  
Reading Frame ◽  
Controlled Atmospheres ◽  
Foliar Senescence

A cDNA clone encoding malate synthase (MS; EC 4.1.3.2) was isolated from a 48-h postharvest asparagus (Asparagus officinalis L.) spear cDNA library using a MS clone from Brassica napus. The asparagus MS (AoMS1) cDNA hybridized to a 1.9-kb transcript that increased in abundance preferentially in spear-tip tissue during postharvest storage. The AoMS1 transcript also accumulated during natural foliar senescence of asparagus fern. The cDNA consists of 1960 nucleotides with an open reading frame of 1665 nucleotides or 555 amino acids, and encodes a deduced protein with a predicted Mr of 63 kDa and a pI of 8.1. The deduced amino acid sequence of AoMS1 showed high identity with the B. napus MS clone (77.2%) used to isolate it, and with MS from cucumber (77%). Genomic Southern analysis suggests that a single gene in asparagus encodes AoMS1. Controlled- atmosphere treatments aimed at reducing deterioration of harvested asparagus spears reduced the expression of AoMS1. The reduction was correlated with the reduced oxygen level, and reduced MS enzyme activity was also observed. Asparagus cell cultures were used to test the role of sugar status in regulating AoMS1 gene expression. In cultures without sucrose there was an accumulation of AoMS1 transcript that was absent in cultures containing sucrose.

scholarly journals A Fluoroquinolone Induces a Novel Mitogen-Encoding Bacteriophage in Streptococcus canis

2003 ◽  
Vol 71 (6) ◽  
pp. 3028-3033 ◽  
Author(s):  
Keely T. Ingrey ◽  
Jun Ren ◽  
John F. Prescott
Keyword(s):  
Toxic Shock Syndrome ◽  
Peripheral Blood Lymphocytes ◽  
Open Reading Frame ◽  
Streptococcal Toxic Shock Syndrome ◽  
Phytolacca Americana ◽  
Toxic Shock ◽  
Amino Acid Similarity ◽  
Reading Frame ◽  
Reverse Transcription Pcr ◽  
Streptococcus Canis

ABSTRACT This study investigated whether the recently recognized emergence of canine streptococcal toxic shock syndrome (STSS) and necrotizing fasciitis (NF) might be partly attributed to the use of fluoroquinolones to treat Streptococcus canis infections in dogs. Both mitomycin and the fluoroquinolone enrofloxacin caused bacteriophage-induced lysis of S. canis strain 34, an isolate from a case of canine STSS and NF. Fluoroquinolone-evoked, bacteriophage-induced lysis occurred over a range of concentrations similar to those that would occur after treatment of dogs with these agents. To search for a possible bacteriophage-encoded streptococcal superantigen gene(s), a library of the 36.5 (±1.1)-kb bacteriophage, designated φsc1, was made by ligating 3- to 7-kb Tsp5091-digested φsc1 fragments into an EcoRI-digested λZapII vector. Recombinants were screened for mitogenic activity by using canine peripheral blood lymphocytes. Of 800 recombinants screened, 11 recombinants with mitogenic effects were identified, and their inserts were sequenced. The highest homology of 11.6 kb of sequenced φsc1 DNA was to the completely sequenced Streptococcus pneumoniae bacteriophage MM1. Seven of the 11 φsc1 sequenced inserts contained a 552-bp open reading frame, scm, with 27% amino acid similarity to pokeweed (Phytolacca americana) mitogen. PCR showed this gene to be present in 22 of 23 S. canis isolates tested. Quantitative reverse transcription-PCR showed that bacteriophage induction was associated with a 58-fold enhancement of expression of this gene relative to that in a noninduced culture of a similar age. The presence of this gene on a fluoroquinolone-induced bacteriophage may explain the association observed between fluoroquinolone use in dogs and the development of canine STTS and NF.

scholarly journals IRES-mediated ribosome repositioning directs translation of a +1 overlapping ORF that enhances viral infection

2018 ◽  
Author(s):  
Craig H Kerr ◽  
Qing S Wang ◽  
Kyung-Mee Moon ◽  
Kathleen Keatings ◽  
Douglas W Allan ◽  
...  
Keyword(s):  
Translation Initiation ◽  
Stop Codon ◽  
Open Reading Frame ◽  
Wild Type Virus ◽  
Infection Model ◽  
Entry Site ◽  
Internal Ribosome Entry ◽  
Reading Frame ◽  
Coding Capacity ◽  
Paralysis Virus

AbstractRNA structures can interact with the ribosome to alter translational reading frame maintenance and promote recoding that result in alternative protein products. Here, we show that the internal ribosome entry site (IRES) from the dicistrovirus Cricket paralysis virus drives translation of the 0-frame viral polyprotein and an overlapping +1 open reading frame, called ORFx, via a novel mechanism whereby a subset of ribosomes recruited to the IRES bypasses downstream to resume translation at the +1-frame 13th non-AUG codon. A mutant of CrPV containing a stop codon in the +1 frame ORFx sequence, yet synonymous in the 0-frame, is attenuated compared to wild-type virus in a Drosophila infection model, indicating the importance of +1 ORFx expression in promoting viral pathogenesis. This work demonstrates a novel programmed IRES-mediated recoding strategy to increase viral coding capacity and impact virus infection, highlighting the diversity of RNA-driven translation initiation mechanisms in eukaryotes.Significance StatementViruses use alternate mechanisms to increase the coding capacity of their viral genomes. Here, we provide biochemical evidence that ribosomes recruited to the dicistrovirus cricket paralysis virus IRES undergo a bypass event to direct translation of a downstream +1 frame overlapping open reading frame, called ORFx. Mutations that block ORFx expression inhibit +1 frame translation and infection in fruit flies. These findings highlight the diversity of RNA-driven translation initiation mechanisms in eukaryotes.

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