Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022104 (irritable bowel syndrome)
 8,033 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A comparative analysis of the plant intron-containing mitochondrial cytochrome oxidase subunit II (coxII) genes provides an indication that four conserved sequence motifs, present in exon 1 (intron-binding sequences; IBS), and complementary motifs (exon-binding sequences; EBS), present in domain I of the group II intron, may be involved in splicing of the intron. Two of these potential IBS motifs (IBS1 and IBS2) have been previously discussed. Two further potential IBS motifs (IBSa and IBSb), which occur twice within exon 1, could be involved in specification of the 5' splice site and of a 5' cryptic splice site. Nuclease-protection experiments and DNA sequence analysis of a spliced coxII cDNA have confirmed the predicted positions of the petunia coxII 5' and 3' splice sites. Evidence for the occurrence of splicing in vivo at the putative 5' cryptic splice site in petunia is provided by the detection of a nuclease-protected fragment corresponding to the size which is predicted if splicing at the proposed cryptic splice site occurs. The existence and location of a cryptic splice site, upstream of the normal coxII 5' splice site, is consistent with the proposed derivation of the cytoplasmic male sterility (CMS)-associated pcf gene from an abnormally spliced coxII transcript (Pruitt and Hanson 1989).
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PMID:Splicing of the Petunia cytochrome oxidase subunit II intron. 171 57

The first intron of the mitochondrial gene coding for cytochrome oxidase subunit I (COI I1) of Podospora anserina can undergo self-splicing in vitro at high concentrations of NH4Cl or KCl. Under these conditions cleavage at the 5' splice junction takes place without branch formation probably via hydrolysis by water or OH- and the intron is released in a linear form. In vitro transcripts that contain mutated introns with large deletions in nonconserved domain IV comprising greater than 50% of the intronic sequence display a more efficient splicing reaction and, surprisingly, 5' cleavage via transesterification and lariat formation is re-established to a low degree under NH4Cl. In contrast to the self-splicing group II introns aI5 gamma and bI1 from yeast mitochondria cleavage at the 3' splice site of the Podospora intron is reduced and cleavage by hydrolysis in trans (i.e. exon reopening) is almost completely suppressed. Both observations could be interpreted as a result of unfavourable spatial conformations of the intron that (i) lead to a steric hindrance of the 5' exon to attack the 3' splice site in cis and (ii) block intron-dependent cleavage reaction of the ligated exons in trans. Alternatively, the possibility that a weak overall interaction of the postulated exon- with the corresponding intron-binding sites (EBS-IBS pairings) is responsible for the remarkable differences to the self-splicing reaction of other group II introns is discussed.
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PMID:Self-splicing of the mobile group II intron of the filamentous fungus Podospora anserina (COI I1) in vitro. 216 69

Group II introns encode reverse transcriptases that promote RNA splicing (maturase activity) and then with the excised intron form a DNA endonuclease that mediates intron mobility by target DNA-primed reverse transcription (TPRT). Here, we show that the primary binding site for the maturase (LtrA) encoded by the Lactococcus lactis Ll.LtrB intron is within a region of intron domain IV that includes the start codon of the LtrA ORF. This binding is enhanced by other elements, particularly domain I and the EBS/IBS interactions, and helps position LtrA to initiate cDNA synthesis in the 3' exon as occurs during TPRT. Our results suggest how the maturase functions in RNA splicing and support the hypothesis that the reverse transcriptase coding region was derived from an independent genetic element that was inserted into a preexisting group II intron.
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PMID:A reverse transcriptase/maturase promotes splicing by binding at its own coding segment in a group II intron RNA. 1048 39

Higher plant mitochondria mainly contain group II introns presenting a secondary structure with six helical domains linked to a central hub. Experimental evidence of functional elements in higher plant mitochondria introns is limited since they are unable to undergo self-splicing and the definition of functional domains is based on data obtained from yeast autocatalytic introns. Here we study the role of putative functional elements required for the splicing reaction. The exon-binding and intron-binding sites (EBS and IBS, respectively), and the domain 6, which is involved in lariat formation, were analysed by site-directed mutagenesis and transient expression in electroporated mitochondria. The data presented here demonstrate the role of EBS1-IBS1 and EBS2-IBS2 interactions and reveal a new secondary-structure interaction. The role of the C to U editing conversion in the IBS1 motif is discussed.
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PMID:RNA splicing in higher plant mitochondria: determination of functional elements in group II intron from a chimeric cox II gene in electroporated wheat mitochondria. 1185 20

Keratins, the major structural protein of all epithelia are a diverse group of cytoskeletal scaffolding proteins that form intermediate filament networks, providing structural support to keratinocytes that maintain the integrity of the skin. Expression of keratin genes is usually regulated by differentiation of the epidermal cells within the stratifying squamous epithelium. Amongst the 54 known functional keratin genes in humans, about 22 different genes including, the cornea, hair and hair follicle-specific keratins have been implicated in a wide range of hereditary diseases. The exact phenotype of each disease usually reflects the spatial expression level and the types of mutated keratin genes, the location of the mutations and their consequences at sub-cellular levels as well as other epigenetic and/or environmental factors. The identification of specific pathogenic mutations in keratin disorders formed the basis of our understanding that led to re-classification, improved diagnosis with prognostic implications, prenatal testing and genetic counseling in severe keratin genodermatoses. Molecular defects in cutaneous keratin genes encoding for keratin intermediate filaments (KIFs) causes keratinocytes and tissue-specific fragility, accounting for a large number of genetic disorders in human skin and its appendages. These diseases are characterized by keratinocytes fragility (cytolysis), intra-epidermal blistering, hyperkeratosis, and keratin filament aggregation in severely affected tissues. Examples include epidermolysis bullosa simplex (EBS; K5, K14), keratinopathic ichthyosis (KPI; K1, K2, K10) i.e. epidermolytic ichthyosis (EI; K1, K10) and ichthyosis bullosa of Siemens (IBS; K2), pachyonychia congenita (PC; K6a, K6b, K16, K17), epidermolytic palmo-plantar keratoderma (EPPK; K9, (K1)), monilethrix (K81, K83, K86), ectodermal dysplasia (ED; K85) and steatocystoma multiplex. These keratins also have been identified to have roles in apoptosis, cell proliferation, wound healing, tissue polarity and remodeling. This review summarizes and discusses the clinical, ultrastructural, molecular genetics and biochemical characteristics of a broad spectrum of keratin-related genodermatoses, with special clinical emphasis on EBS, EI and PC. We also highlight current and emerging model tools for prognostic future therapies. Hopefully, disease modeling and in-depth understanding of the molecular pathogenesis of the diseases may lead to the development of novel therapies for several hereditary cutaneous diseases.
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PMID:Keratin gene mutations in disorders of human skin and its appendages. 2117 69

Group II introns are self-splicing, retrotransposable ribozymes that contribute to gene expression and evolution in most organisms. The ongoing identification of new group II introns and recent bioinformatic analyses have suggested that there are novel lineages, which include the group IIE and IIF introns. Because the function and biochemical activity of group IIE and IIF introns have never been experimentally tested and because these introns appear to have features that distinguish them from other introns, we set out to determine if they were indeed self-splicing, catalytically active RNA molecules. To this end, we transcribed and studied a set of diverse group IIE and IIF introns, quantitatively characterizing their in vitro self-splicing reactivity, ionic requirements, and reaction products. In addition, we used mutational analysis to determine the relative role of the EBS-IBS 1 and 2 recognition elements during splicing by these introns. We show that group IIE and IIF introns are indeed distinct active intron families, with different reactivities and structures. We show that the group IIE introns self-splice exclusively through the hydrolytic pathway, while group IIF introns can also catalyze transesterifications. Intriguingly, we observe one group IIF intron that forms circular intron. Finally, despite an apparent EBS2-IBS2 duplex in the sequences of these introns, we find that this interaction plays no role during self-splicing in vitro. It is now clear that the group IIE and IIF introns are functional ribozymes, with distinctive properties that may be useful for biotechnological applications, and which may contribute to the biology of host organisms.
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PMID:Predicted group II intron lineages E and F comprise catalytically active ribozymes. 2388 13

There is a significant data about overlap of functional dyspepsia (FD) and irritable bowel syndrome (IBS), however mostly the data is based on the previous diagnostic criteria and do not include other pathologies. In the previous researches there were no differential statistical analysis performed for different types of FD - postprandial distress syndrome (PDS) and epigastric pain syndrome (EBS). Aim of the study - to assess potential risk factors and the prevalence of comorbid conditions associated with FD and to compare their frequency with the same in the group with no dyspeptic complaints and in patients with different types of FD - PDS and EPS. This study was conducted as a retrospective database analysis of the patients with newly set diagnosis of FD and control group. For all the cases the information on demographic (working status, family status) and lifestyle characteristics (body mass index, smoking status, and alcohol consumption), and comorbidities were collected from the medical files. We statistically analyzed the presence of risk factors, comorbidity and its frequency in the patients with FD and compared the results with control group and in the groups with different types of FD according to the generally accepted standards. This study included 158 patients with PDS, 87 patients with EBS, and 90 volunteers with no dyspeptic complaints. Smoking, alcohol consumption, and family status were not associated with the risk of FD. The presence of sleep disorders and being unemployed increased the risk of FD. The comparison of the results of the patients with different types of FD demonstrated that there were no statistical difference in risk factors for the PDS and EPS. Gastroesophageal reflux disease (GERD), IBS, chronic gastritis and / or duodenitis, anxiety, and depression occur more frequently in the group of patients with FD. No association between autoimmune thyroiditis (AIT), arterial hypertension and ischemic heart disease (IHD) was evaluated. There was no statistical difference for the frequency of GERD, chronic gastritis and / or duodenitis, anxiety, AIT, arterial hypertension, and IHD in the patients with different types of FD. However, it was evaluated that IBS and depression occur more frequently in the group of patients with PDS, than in the patients with EPS.
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PMID:RISK FACTORS AND COMORBIDITY IN DIFFERENT TYPES OF FUNCTIONAL DYSPEPSIA: RETROSPECTIVE COHORT ANALYSIS. 3327 May 86