16 research outputs found

    Comparison of Modules of Wild Type and Mutant Huntingtin and TP53 Protein Interaction Networks: Implications in Biological Processes and Functions

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    Disease-causing mutations usually change the interacting partners of mutant proteins. In this article, we propose that the biological consequences of mutation are directly related to the alteration of corresponding protein protein interaction networks (PPIN). Mutation of Huntingtin (HTT) which causes Huntington's disease (HD) and mutations to TP53 which is associated with different cancers are studied as two example cases. We construct the PPIN of wild type and mutant proteins separately and identify the structural modules of each of the networks. The functional role of these modules are then assessed by Gene Ontology (GO) enrichment analysis for biological processes (BPs). We find that a large number of significantly enriched (p<0.0001) GO terms in mutant PPIN were absent in the wild type PPIN indicating the gain of BPs due to mutation. Similarly some of the GO terms enriched in wild type PPIN cease to exist in the modules of mutant PPIN, representing the loss. GO terms common in modules of mutant and wild type networks indicate both loss and gain of BPs. We further assign relevant biological function(s) to each module by classifying the enriched GO terms associated with it. It turns out that most of these biological functions in HTT networks are already known to be altered in HD and those of TP53 networks are altered in cancers. We argue that gain of BPs, and the corresponding biological functions, are due to new interacting partners acquired by mutant proteins. The methodology we adopt here could be applied to genetic diseases where mutations alter the ability of the protein to interact with other proteins.Comment: 35 pages, 10 eps figures, (Supplementary material and Datasets are available on request

    Glutamate and cyclic AMP regulate the expression of galactokinase in Mycobacterium smegmatis

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    It was found that Mycobacterium smegmatis is unable to utilize galactose as the sole carbon source because the sugar alone cannot induce galactokinase. However, galactokinase was induced by glutamate alone, and was further stimulated by galactose. Rifampicin completely inhibited the glutamate-mediated expression of galK in both the absence and presence of galactose. Extracellular cAMP stimulated the expression of the enzyme only in the presence of glutamate plus galactose. The galK gene from M. smegmatis, including its upstream promoter region, was cloned in a plasmid in Escherichia coli. The expression of kinase from these clones in E. coli was dependent on cAMP and its receptor protein (CRP). The expression of UDP-galactose 4-epimerase was constitutive. This and other evidence suggests that the galK gene is not linked to galT and galE in the mycobacterial genome. In a glutamate-independent galactose-utilizing mutant (gin-1 mutant) of M. smegmatis, galK was expressed in the absence of both galactose and glutamate, while in the presence of galactose this expression was increased twofold in the absence of glutamate and fourfold in its presence. Extracellularly added cAMP reduced the expression of the enzyme in the presence of galactose plus glutamate nearly to the basal level. It is proposed that in M. smegmatis the galK gene is expressed from two different promoters; the expression from one promoter is dependent on glutamate but not on galactose and cAMP, while that from the other requires all three components. The role of galactose is possibly to derepress the latter promoter

    Prevalence of SARS-CoV-2 positivity in infants with bronchiolitis: a multicentre international study

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    Background Bronchiolitis is the leading acute respiratory tract infection in infants during the winter season. Since the beginning of the SARS-CoV-2 pandemic, a reduction in the number of bronchiolitis diagnoses has been registered. Objective The present study aimed to describe the incidence and clinical features of bronchiolitis during the 2020-2021 winter season in a large cohort of children in Europe and Israel, and to clarify the role of SARS-CoV-2. Setting, patients, interventions We conducted a multicentre observational cross-sectional study in 23 paediatric emergency departments in Europe and Israel. Clinical and demographic data about all the cases of infants diagnosed with bronchiolitis from 1 October 2020 to 30 April 2021 were collected. For each enrolled patient, diagnostic tests, treatments and outcomes were reported. Main outcome measures The main outcome was the prevalence of SARS-CoV-2-positive bronchiolitis. Results Three hundred and fourteen infants received a diagnosis of bronchiolitis during the study period. Among 535 infants who tested positive for SARS-CoV-2, 16 (3%) had bronchiolitis. Median age, male sex predominance, weight, history of prematurity and presence of comorbidities did not differ between the SARS-CoV-2-positive and SARS-CoV-2-negative groups. Rhinovirus was the most common involved pathogen, while respiratory syncytial virus (RSV) was detected in one case. SARS-CoV-2 bronchiolitis had a mild clinical course, with one patient receiving oxygen supplementation and none requiring paediatric or neonatal intensive care unit admission. Conclusions During the SARS-CoV-2 pandemic, a marked decrease in the number of bronchiolitis diagnoses and the disappearance of the RSV winter epidemic were observed. SARS-CoV-2-related bronchiolitis was rare and mostly displayed a mild clinical course.During the SARS-CoV-2 pandemic, very few infants with SARS-CoV-2 had bronchiolitis and mostly displayed a mild clinical course. Overall there was a marked decrease in bronchiolitis cases, indeed the RSV winter epidemic did not occur

    "The fruits of independence": Satyajit Ray, Indian nationhood and the spectre of empire

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    Challenging the longstanding consensus that Satyajit Ray's work is largely free of ideological concerns and notable only for its humanistic richness, this article shows with reference to representations of British colonialism and Indian nationhood that Ray's films and stories are marked deeply and consistently by a distinctively Bengali variety of liberalism. Drawn from an ongoing biographical project, it commences with an overview of the nationalist milieu in which Ray grew up and emphasizes the preoccupation with colonialism and nationalism that marked his earliest unfilmed scripts. It then shows with case studies of Kanchanjangha (1962), Charulata (1964), First Class Kamra (First-Class Compartment, 1981), Pratidwandi (The Adversary, 1970), Shatranj ke Khilari (The Chess Players, 1977), Agantuk (The Stranger, 1991) and Robertsoner Ruby (Robertson's Ruby, 1992) how Ray's mature work continued to combine a strongly anti-colonial viewpoint with a shifting perspective on Indian nationhood and an unequivocal commitment to cultural cosmopolitanism. Analysing how Ray articulated his ideological positions through the quintessentially liberal device of complexly staged debates that were apparently free, but in fact closed by the scenarist/director on ideologically specific notes, this article concludes that Ray's reputation as an all-forgiving, ‘everybody-has-his-reasons’ humanist is based on simplistic or even tendentious readings of his work

    Distribution of microRNA co-targets exhibit universality across a wide class of species

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    MicroRNAs (miRNAs) are small non-coding RNAs which regulate gene expression by binding to the 33' UTR of the corresponding messenger RNAs. We construct miRNA co-target networks for a wide class of species (22 in total) using a target prediction database, MicroCosm Targets. For each species, miRNA pairs having one or more common target genes are connected and the number of co-targets are assigned as the weight of these links. We show that the link-weight distributions of all the species collapse remarkably onto each other when scaled suitably —the scale-factor turns out to be a measure of complexity of the species. A simple model, where targets are chosen randomly by miRNAs, could provide the correct scaling function and suggest that the increase of species complexity is related to the increase of the fraction of genes typically targeted by their miRNAs

    Haplotype Analysis of Genomic Polymorphisms in and Around the Myotonic Dystrophy Locus in Diverse Populations of India

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    The frequencies of haplotypes based upon the (CTG)n repeat and three other biallelic markers in and around the myotonic dystrophy (DM) locus were estimated in 13 ethnically, linguistically and geographically diverse sub-populations of India. The range of CTG repeats in caste populations was 5–31, while in tribal populations the range was shorter (5–23). Extensive variation in frequencies of large (CTG)n alleles (≥18 repeats) was found in Indian populations. The implications of this finding on DM epidemiology are discussed. Haplotype diversity was found to be very high in most populations. The majority of the Indian DM patients carried a haplotype that is commonly found among DM patients globally; this is the most common haplotype in the class of large (≥18 repeats) CTG alleles. However, one haplotype was found to be present in particularly high frequency in Indian populations; this haplotype was also found among Indian DM patients. This haplotype may be a characteristic of Indian and possibly of other East Asian populations
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