bluuebunny/crossref_metadata_2025_split huggingface dataset:
Review of Phosphodiesterases in the Urogenital System: New Directions for Therapeutic Intervention
Authors: Montorsi Francesco , Corbin Jackie , Phillips Stephen 
Published: October 2004

ABSTRACT

Introduction
With the success of Phosphodiesterase (PDE) type 5 inhibitors (i.e., sildenafil, tadalafil, vardenafil) in the treatment of erectile dysfunction (ED), PDEs are considered attractive targets for drug intervention in the urogenital tract.

Aim
To review the role of PDEs, which exist as a superfamily of enzymes comprising 11 distinct families, in the urogenital system, focusing on anatomical locations, functions and dysfunctions, potential disorders that could be treated, and any promising new selective PDE inhibitors under development.

Methods
Included are (i) abstracts from 2001, 2002, and 2003; (ii) a MEDLINE search from 1996 through December 2003; and (iii) a pipeline search for therapeutics in development. Data from animal experiments are presented when there is a paucity of human data, but with the caveat that the distribution of PDE isozymes in a specific tissue can vary between species.

Results
PDE mRNA and protein have been localized throughout the normal human urogenital tract. Double-blind, placebo-controlled studies suggest possible new clinical roles for sildenafil, including prophylaxis to preserve penile smooth muscle and erectile function after radical prostatectomy, and treatment of ejaculatory delay secondary to serotonergic reuptake inhibitor antidepressant therapy. Open-label studies suggest a potential clinical role for: vinpocetine (a PDE1 inhibitor) in the treatment of incontinence and low-compliance bladder; and sildenafil in the treatment of premature ejaculation, prostate-related lower urinary tract symptoms, and in women who have had unsuccessful in vitro fertilization. Several new orally administered PDE5 inhibitors are in early clinical development for the treatment of ED. Potential indications for PDE inhibitors that are suggested by preclinical data include Peyronie's disease, ureteral colic, male and female birth control, and prevention of preterm labor.

Conclusion
Drug selectivity and differential PDE tissue distribution allow for potential targeted intervention for numerous disorders related to the urogenital tract.
Possible Correlation Between Type 1 Diabetes Mellitus and Female Sexual Dysfunction: Case Report and Literature Review
Authors: Bultrini Antonella , Carosa Eleonora , Colpi Elisabetta M. , Poccia Gianfranco , Iannarelli Rossella , Lembo Danilo , Lenzi Andrea , Jannini Emmanuele A. 
Published: October 2004

ABSTRACT

Introduction
Sexual dysfunction in diabetic women has received less attention in clinical research than the sexual symptoms of diabetic men. Although conflicting results have been reported, several studies suggest an increased prevalence of deficient vaginal lubrication in women with diabetes mellitus. As support to the hypothesis of a potential diabetes-related arousal dysfunction caused by a decrease in vaginal lubrication of women with Type 1 diabetes mellitus, we describe the following case report.

Methods
A 29-year-old white woman was found with a sexual arousal disorder of sudden onset, complicated by loss of orgasm and sexual desire, in absence of any marital, relational, psychological, or gynecological cause.

Results
One month later she was diagnosed with severe Type 1 diabetes. With the correction of diabetes and without other treatment of the sexual dysfunction, she experienced a full recovery of her sexual complaints.

Conclusion
The case illustrates the importance of being aware of female sexual dysfunction as an early symptom of diabetes mellitus and suggests that a good glycemic control would be fundamental to restore a normal sexual activity in diabetic women. It also demonstrates the need to take into account, not only in males, a sexual history in the management of diabetes mellitus.
MicC, a Second Small-RNA Regulator of Omp Protein Expression inEscherichia coli
Authors: Chen Shuo , Zhang Aixia , Blyn Lawrence B. , Storz Gisela 
Published: October 2004

ABSTRACTIn a previous bioinformatics-based search for novel small-RNA genes encoded by theEscherichia coligenome, we identified a region, IS063, located between theompNandydbKgenes, that encodes an ∼100-nucleotide small-RNA transcript. Here we show that the expression of this small RNA is increased at a low temperature and in minimal medium. Twenty-two nucleotides at the 5′ end of this transcript have the potential to form base pairs with the leader sequence of the mRNA encoding the outer membrane protein OmpC. The deletion of IS063 increased the expression of anompC-luctranslational fusion 1.5- to 2-fold, and a 10-fold overexpression of the small RNA led to a 2- to 3-fold repression of the fusion. Deletion and overexpression of the IS063 RNA also resulted in increases and decreases, respectively, in OmpC protein levels. Taken together, these results suggest that IS063is a regulator of OmpC expression; thus, the small RNA has been renamed MicC. The antisense regulation was further demonstrated by the finding thatmicCmutations were suppressed by compensatory mutations in theompCmRNA. MicC was also shown to inhibit ribosome binding to theompCmRNA leader in vitro and to require the Hfq RNA chaperone for its function. We suggest that the MicF and MicC RNAs act in conjunction with the EnvZ-OmpR two-component system to control the OmpF/OmpC protein ratio in response to a variety of environmental stimuli.
GadY, a Small-RNA Regulator of Acid Response Genes inEscherichia coli
Authors: Opdyke Jason A. , Kang Ju-Gyeong , Storz Gisela 
Published: October 2004

ABSTRACTA previous bioinformatics-based search for small RNAs inEscherichia coliidentified a novel RNA named IS183. The gene encoding this small RNA is located between and on the opposite strand of genes encoding two transcriptional regulators of the acid response,gadX(yhiX) andgadW(yhiW). Given that IS183 is encoded in thegadgene cluster and because of its role in regulating acid response genes reported here, this RNA has been renamed GadY. We show that GadY exists in three forms, a long form consisting of 105 nucleotides and two processed forms, consisting of 90 and 59 nucleotides. The expression of this small RNA is highly induced during stationary phase in a manner that is dependent on the alternative sigma factor σS. Overexpression of the three GadY RNA forms resulted in increased levels of the mRNA encoding the GadX transcriptional activator, which in turn caused increased levels of the GadA and GadB glutamate decarboxylases. A promoter mutation which abolishedgadYexpression resulted in a reduction in the amount ofgadXmRNA during stationary phase. ThegadYgene was shown to overlap the 3′ end of thegadXgene, and this overlap region was found to be necessary for the GadY-dependent accumulation ofgadXmRNA. We suggest that during stationary phase, GadY forms base pairs with the 3′-untranslated region of thegadXmRNA and confers increased stability, allowing forgadXmRNA accumulation and the increased expression of downstream acid resistance genes.
Identification of a Staphylococcal AgrB Segment(s) Responsible for Group-Specific Processing of AgrD by Gene Swapping
Authors: Zhang Linsheng , Ji Guangyong 
Published: October 2004

ABSTRACT

The four gene products of the accessory gene regulator (
agr
) P2 operon of
Staphylococcus aureus
assemble a quorum-sensing system: AgrA and AgrC resemble a two-component signal transduction system, and AgrB and AgrD are required to produce an autoinducing peptide. Upon activation, this quorum-sensing system positively regulates the transcription of the P2 operon as well as the P3 operon, whose transcript, RNAIII, regulates the expression of virulence genes. Four groups of
S. aureus
have been identified based on the
agr
sequences and the group-specific interaction between the autoinducing peptide and AgrC. AgrB is a transmembrane protein involved in the processing of AgrD propeptide, and its interaction with AgrD is also group specific. In this study, a series of chimeric AgrBs were constructed by swapping between group I and group II AgrBs, and these mutants were used to analyze the group-specific segment(s) in AgrB that was responsible for AgrD processing. Our results revealed that the first transmembrane α-helix and the extracellular loop 1 of group I AgrB were decisive in the specific processing of group I AgrD. In contrast, two hydrophilic segments of group II AgrB played a crucial role in the group-specific processing of group II AgrD. We also found that several chimeric AgrBs were capable of processing AgrD from both groups, suggesting that all AgrB homologues may utilize the same or a similar mechanism in the processing of AgrDs.
Global Transcriptional Effects of a Suppressor tRNA and the Inactivation of the Regulator
frmR
Authors: Herring Christopher D. , Blattner Frederick R. 
Published: October 2004

ABSTRACT

Expression of an amber suppressor tRNA should result in read-through of the 326 open reading frames (ORFs) that terminate with amber stop codons in the
Escherichia coli
genome, including six pseudogenes. Abnormal extension of an ORF might alter the activities of the protein and have effects on cellular physiology, while suppression of a pseudogene could lead to a gain of function. We used oligonucleotide microarrays to determine if any effects were apparent at the level of transcription in glucose minimal medium. Surprisingly, only eight genes had significantly different expression in the presence of the suppressor. Among these were the genes
yaiN
,
adhC
, and
yaiM
, forming a single putative operon whose likely function is the degradation of formaldehyde. Expression of wild-type
yaiN
was shown to result in repression of the operon, while a suppression-mimicking allele lacking the amber stop codon and extended 7 amino acids did not. The operon was shown to be induced by formaldehyde, and the genes have been renamed
frmR
,
frmA
, and
frmB
, respectively.
TheEscherichia coli dnaN159Mutant Displays Altered DNA Polymerase Usage and Chronic SOS Induction
Authors: Sutton Mark D. 
Published: October 2004

ABSTRACTTheEscherichia coliβ sliding clamp, which is encoded by thednaNgene, is reported to interact with a variety of proteins involved in different aspects of DNA metabolism. Recent findings indicate that many of these partner proteins interact with a common surface on the β clamp, suggesting that competition between these partners for binding to the clamp might help to coordinate both the nature and order of the events that take place at a replication fork. The purpose of the experiments discussed in this report was to test a prediction of this model, namely, that a mutant β clamp protein impaired for interactions with the replicative DNA polymerase (polymerase III [Pol III]) would likewise have impaired interactions with other partner proteins and hence would display pleiotropic phenotypes. Results discussed herein indicate that thednaN159-encoded mutant β clamp protein (β159) is impaired for interactions with the α catalytic subunit of Pol III. Moreover, thednaN159mutant strain displayed multiple replication and repair phenotypes, including sensitivity to UV light, an absolute dependence on the polymerase activity of Pol I for viability, enhanced Pol V-dependent mutagenesis, and altered induction of the global SOS response. Furthermore, epistasis analyses indicated that the UV sensitivity of thednaN159mutant was suppressed by (not epistatic with) inactivation of Pol IV (dinBgene product). Taken together, these findings suggest that in thednaN159mutant, DNA polymerase usage, and hence DNA replication, repair, and translesion synthesis, are altered. These findings are discussed in terms of a model to describe how the β clamp might help to coordinate protein traffic at the replication fork.
Functional and Structural Analysis of HrcA Repressor Protein from
Caulobacter crescentus
Authors: Susin Michelle F. , Perez Humberto R. , Baldini Regina L. , Gomes Suely L. 
Published: October 2004

ABSTRACT

A large number of bacteria regulate chaperone gene expression during heat shock by the HrcA-CIRCE system, in which the DNA element called CIRCE serves as binding site for the repressor protein HrcA under nonstress conditions. In
Caulobacter crescentus
, the
groESL
operon presents a dual type of control. Heat shock induction is controlled by a σ
32
-dependent promoter and the HrcA-CIRCE system plays a role in regulation of
groESL
expression under physiological temperatures. To study the activity of HrcA in vitro, we purified a histidine-tagged version of the protein, and specific binding to the CIRCE element was obtained by gel shift assays. The amount of retarded DNA increased significantly in the presence of GroES/GroEL, suggesting that the GroE chaperonin machine modulates HrcA activity. Further evidence of this modulation was obtained using
lacZ
transcription fusions with the
groESL
regulatory region in
C. crescentus
cells, producing different amounts of GroES/GroEL. In addition, we identified the putative DNA-binding domain of HrcA through extensive protein sequence comparison and constructed various HrcA mutant proteins containing single amino acid substitutions in or near this region. In vitro and in vivo experiments with these mutated proteins indicated several amino acids important for repressor activity.
Modulation of Monomer Conformation of the BglG Transcriptional Antiterminator from
Escherichia coli
Authors: Fux Liat , Nussbaum-Shochat Anat , Lopian Livnat , Amster-Choder Orna 
Published: October 2004

ABSTRACT

The BglG protein positively regulates expression of the
bgl
operon in
Escherichia coli
by binding as a dimer to the
bgl
transcript and preventing premature termination of transcription in the presence of β-glucosides. BglG activity is negatively controlled by BglF, the β-glucoside phosphotransferase, which reversibly phosphorylates BglG according to β-glucoside availability, thus modulating its dimeric state. BglG consists of an RNA-binding domain and two homologous domains, PRD1 and PRD2. Based on structural studies of a BglG homologue, the two PRDs fold similarly, and the interactions within the dimer are PRD1-PRD1 and PRD2-PRD2. We have recently shown that the affinity between PRD1 and PRD2 of BglG is high, and a fraction of the BglG monomers folds in the cell into a compact conformation, in which PRD1 and PRD2 are in close proximity. We show here that both BglG forms, the compact and noncompact, bind to the active site-containing domain of BglF, IIB
bgl
, in vitro. The interaction of BglG with IIB
bgl
or BglF is mediated by PRD2. Both BglG forms are detected as phosphorylated proteins after in vitro phosphorylation with IIB
bgl
and are dephosphorylated by BglF in vitro in the presence of β-glucosides. Nevertheless, genetic evidence indicates that the interaction of IIB
bgl
and BglF with the compact form is seemingly less favorable. Using in vivo cross-linking, we show that BglF enhances folding of BglG into a compact conformation, whereas the addition of β-glucosides reduces the amount of this form. Based on these results we suggest a model for the modulation of BglG conformation and activity by BglF.
The Glutathione-Glutaredoxin System inRhodobacter capsulatus: Part of a Complex Regulatory Network Controlling Defense against Oxidative Stress
Authors: Li Kuanyu , Hein Silke , Zou Wenxin , Klug Gabriele 
Published: October 2004

ABSTRACTMutants with defects in components of the glutathione-glutaredoxin (GSH/Grx) system ofRhodobacter capsulatuswere constructed to study its role in defense against oxidative stress and the redox-dependent formation of photosynthetic complexes. The lack of the glutaredoxin 3 gene (grxC) or the glutathione synthetase B gene (gshB) resulted in lower growth rates under aerobic conditions and higher sensitivity to oxidative stress, confirming the role of the GSH/Grx system in oxidative stress defense. Both mutants are highly sensitive to disulfide stress, indicating a major contribution of the GSH/Grx system to the thiol-disulfide redox buffer in the cytoplasm. Like mutations in the thioredoxin system, mutations in the GSH/Grx system affected the formation of photosynthetic complexes, which is redox dependent inR. capsulatus. Expression of the genesgrxC,gshB,grxAfor glutaredoxin 1, andgorAfor glutathione reductase, all encoding components of the GSH/Grx system, was not induced by oxidative stress. Other genes, for which a role in oxidative stress was established inEscherichia coli,acnA,fpr,fur, andkatG, were strongly induced by oxidative stress inR. capsulatus. Mutations in thegrxC, and/orgshB, and/ortrxC(thioredoxin 2) genes affected expression of these genes, indicating an interplay of the different defense systems against oxidative stress. The OxyR and the SoxRS regulons control the expression of many genes involved in oxidative stress defense inE. coliin response to H2O2and superoxide, respectively. Our data and the available genome sequence ofR. capsulatussuggest that a SoxRS system is lacking but an alternative superoxide specific regulator exists inR. capsulatus.While the expression ofgorAandgrxAis regulated by H2O2inE. colithis is not the case inR. capsulatus, indicating that the OxyR regulons of these two species are significantly different.
Effect of Bile on the Cell Surface Permeability Barrier and Efflux System of
Vibrio cholerae
Authors: Chatterjee Arpita , Chaudhuri Sohini , Saha Gargi , Gupta Satadeepa , Chowdhury Rukhsana 
Published: October 2004

ABSTRACT

Gram-negative bacteria are inherently impermeable to hydrophobic compounds, due to the synergistic activity of the permeability barrier imposed by the outer membrane and energy dependent efflux systems. The gram-negative, enteric pathogen
Vibrio cholerae
appears to be deficient in both these activities; the outer membrane is not an effective barrier to hydrophobic permeants, presumably due to the presence of exposed phospholipids on the outer leaflet of the outer membrane, and efflux systems are at best only partially active. When
V. cholerae
was grown in the presence of bile, entry of hydrophobic compounds into the cells was significantly reduced. No difference was detected in the extent of exposed phospholipids on the outer leaflet of the outer membrane between cells grown in the presence or absence of bile. However, in the presence of energy uncouplers, uptake of hydrophobic probes was comparable between cells grown in the presence or absence of bile, indicating that energy-dependent efflux processes may be involved in restricting the entry of hydrophobic permeants into bile grown cells. Indeed, an efflux system(s) is essential for survival of
V. cholerae
in the presence of bile. Expression of
acrAB
, encoding an RND family efflux pump, was significantly increased in
V. cholerae
cells grown in vitro in the presence of bile and also in cells grown in rabbit intestine.
Transcriptional Regulation of the
ant
Operon, Encoding Two-Component Anthranilate 1,2-Dioxygenase, on the Carbazole-Degradative Plasmid pCAR1 of
Pseudomonas resinovorans
Strain CA10
Authors: Urata Masaaki , Miyakoshi Masatoshi , Kai Satoshi , Maeda Kana , Habe Hiroshi , Omori Toshio , Yamane Hisakazu , Nojiri Hideaki 
Published: October 2004

ABSTRACT

The carbazole-degradative plasmid pCAR1 of
Pseudomonas resinovorans
strain CA10 has two gene clusters,
carAaAaBaBbCAcAdDFE
and
antABC
, which are involved in the conversions of carbazole to anthranilate and anthranilate to catechol, respectively. We proved that the
antABC
gene cluster, encoding two-component anthranilate 1,2-dioxygenase, constitutes a single transcriptional unit through Northern hybridization and reverse transcription-PCR (RT-PCR) analyses. The transcription start point of
antA
was mapped at 53 bp upstream point of its translation start point, and the −10 and −35 boxes were homologous to conserved σ
70
recognition sequence. Hence the promoter of the
ant
operon was designated P

ant

. 5′ Deletion analyses using luciferase as a reporter showed that the region up to at least 70 bp from the transcription start point of
antA
was necessary for the activation of P

ant

. Luciferase expression from P

ant

was induced by anthranilate itself, but not by catechol. Two probable AraC/XylS-type regulatory genes found on pCAR1, open reading frame 22 (ORF22) and ORF23, are tandemly located 3.2 kb upstream of the
antA
gene. We revealed that the product of ORF23, designated AntR, is indispensable for the stimulation of P

ant

in
Pseudomonas putida
cells. Northern hybridization and RT-PCR analyses revealed that another copy of P

ant

, which is thought to be translocated about 2.1 kb upstream of the
carAa
gene as a consequence of the transposition of ISPre1, actually drives transcription of the
carAa
gene in the presence of anthranilate, indicating that both
ant
and
car
operons are simultaneously regulated by AntR.
Replicon-Specific Regulation of Small Heat Shock Genes in
Agrobacterium tumefaciens
Authors: Balsiger Sylvia , Ragaz Curdin , Baron Christian , Narberhaus Franz 
Published: October 2004

ABSTRACT

Four genes coding for small heat shock proteins (sHsps) were identified in the genome sequence of
Agrobacterium tumefaciens
, one on the circular chromosome (
hspC
), one on the linear chromosome (
hspL
), and two on the pAT plasmid (
hspAT1
and
hspAT2
). Induction of sHsps at elevated temperatures was revealed by immunoblot analyses. Primer extension experiments and translational
lacZ
fusions demonstrated that expression of the pAT-derived genes and
hspL
is controlled by temperature in a regulon-specific manner. While the sHsp gene on the linear chromosome turned out to be regulated by RpoH (σ
32
), both copies on pAT were under the control of highly conserved ROSE (named for repression of heat shock gene expression) sequences in their 5′ untranslated region. Secondary structure predictions of the corresponding mRNA strongly suggest that it represses translation at low temperatures by masking the Shine-Dalgarno sequence. The
hspC
gene was barely expressed (if at all) and not temperature responsive.
Phosphorylation and RsbX-Dependent Dephosphorylation of RsbR in the RsbR-RsbS Complex ofBacillus subtilis
Authors: Chen Chien-Cheng , Yudkin Michael D. , Delumeau Olivier 
Published: October 2004

ABSTRACTIn the pathway that controls σBactivity, the RsbR-RsbS complex plays an important role by trapping RsbT, a positive regulator of σBofBacillus subtilis. We have proposed that at the onset of stress, RsbR becomes phosphorylated, resulting in an enhanced activity of RsbT towards RsbS. RsbT is then free to interact with and activate RsbU, which in turn ultimately activates σB. In this study with purified proteins, we used mutant RsbR proteins to analyze the role of its phosphorylatable threonine residues. The results show that the phosphorylation of either of the two RsbT-phosphorylatable threonine residues (T171 and T205) in RsbR enhanced the kinase activity of RsbT towards RsbS. However, it appeared that RsbT preferentially phosphorylates T171. We also present in vitro evidence that identifies RsbX as a potential phosphatase for RsbR T205.