1,721,014 research outputs found
INVOLVEMENT OF RAVER1RIBONUCLEOPROTEIN IN SPLICING EVENTSDURING C2C12 MYOBLAST DIFFERENTIATION
No full textAnalisi condotte su larga scala delle sequenze espresse del genoma umano
stimano che la maggior parte dei geni umani subiscono eventi di splicing
alternativo con distribuzione tessuto-specifica. Oltre il 15% delle patologie
genetiche umane sono associate a mutazioni nei siti di splicing e la distruzione di
networks regolatori dello splicing contribuiscono allo sviluppo di numerose
patologie. Lo splicing alternativo del pre-RNA messaggero (pre-mRNA)
rappresenta quindi un’intensa attività regolatoria a livello post-trascrizionale che
coinvolge molte proteine che legano l’RNA e molti fattori che regolano lo
splicing. La proteina PTB (caratterizzata e definita come proteina che si lega a
tratti di poli-pirimidine) e il suo paralogo nel tessuto nervoso, brPTB, svolgono un
ruolo molto definito come regolatori negativi dello splicing nei tessuti
differenziati. Raver1 e Raver2 sono proteine interagenti con PTB ma il cui ruolo,
negli eventi di splicing alternativo non è ancora noto.
Durante lo sviluppo muscolare PTB e brPTB regolano lo splicing alternativo di
molti esoni espressi in modo tessuto specifico. In questo studio è stato indagato
il contributo di Raver1 negli eventi di splicing alternativo che avvengono durante
il differenziamento mioblastico di cellule C2C12. Sono stati inoltre analizzati
l’espressione, la localizzazione subcellulare e il ruolo funzionale di Raver1 negli
eventi di splicing alternativo di alcuni trascritti durante il processo miogenico
delle cellule C2C12. Analisi di microscopia confocale mostrano che Raver1
diffonde nel citoplasma, localizzandosi in un’area citoplasmatica polarizzata
durante il differenziamento dei mioblasti. La sovra-espressione di Raver1 durante
la miogenesi influisce sullo splicing alternativo di esoni regolati della proteasi
calpaina 3 (CAPN3) e della fosfatasi relata alla miotubularina 1 (MTMR1).
Esperimenti di immunoprecipitazione dell’RNA confermano che Raver1 può
legare i pre-mRNA di CAPN3 e di MTMR1 in regioni contenenti putative sequenze
di riconoscimento per PTB. L’espressione di Raver2 è stata inoltre analizzata nei
tessuti umani mostrando che, contrariamente a quanto avviene nel muscolo
scheletrico murino, il gene Raver2 è espresso nel muscolo scheletrico umano.
Questi studi mettono in luce nuovi aspetti circa il ruolo delle ribonucleoproteine
nella regolazione post-trascrizionale di eventi che accadono durante lo sviluppo
muscolare a livello nucleare e a livello citoplasmatico.Large-scale expressed sequence tag and genome-wide analyses estimate that the
majority of human genes undergo alternative splicing with a differential tissue
distribution. More than 15% of human genetic diseases are associated to
mutations in the consensus splice sites and disruption of splicing regulatory
networks contributes to various diseases. Alternative splicing of pre-messenger
RNA represents, consequently, an intensive post-transcriptional regulatory
activity that involves several RNA binding proteins and splicing regulators.
Polypyrimidine tract binding protein (PTB) and its paralog brPTB play a well
established role as negative splicing regulators in differentiated tissues. Raver1
and Raver2 are proteins interacting with PTB but their role in splicing events are
not understood.
During muscle development PTB and brPTB regulate alternative splicing of
several tissue specific exons. In the present study it has been investigated the
contribution of Raver1 to splicing events occurring during myoblasts
differentiation of C2C12 cells. The expression, subcellular localization and
functional role of Raver1 in splicing events of selected transcripts during C2C12
myogenic process have been analyzed. The results show that Raver1 protein is
expressed in proliferating undifferentiated cells as well as in differentiating
myoblast cells. Confocal microscopy analyses show that Raver1 diffuses in the
cytoplasm from the nucleus, localizing in polarized cytoplasmic area during
myoblasts differentiation. Over-expression of Raver1 during myogenesis affects
alternative splicing of regulated exons in protease calpain 3 (CAPN3) and
phosphatase myotubularin-related protein 1 (MTMR1). RNA-Immunoprecipitation
experiments confirm that Raver1 can bind CAPN3 and MTMR1 pre-mRNAs in
regions containing putative PTB recognition sequences. Raver2 expression was
also analyzed in human tissues, showing that in contrast to what happens in
mouse muscle tissue, Raver2 gene is expressed in human skeletal muscle tissue.
These studies may shed new light on the role of ribonucleopreoteins in the posttranscriptional
regulation events that occur during muscle development in both
nuclear and cytoplasmic compartments
Post-transcriptional Gene Regulation: Role of the Polypyrimidine Tract-binding Protein (PTB) and Associated Factors in "From the hallowed halls of Herpesvirology".
No full textThe overall processes of gene expression, from mRNA biogenesis to translation and degradation, require RNA messenger ribonucleoprotein (mRNP) complexes assembly, differentially combined with individual transcripts in order to mediate the post-transcriptional events. One of those events, the alternative splicing of pre-mRNA, is responsible for the wide variety and complexity levels of transcriptome and proteome. Large-scale expressed sequence tag and genome-wide analyses estimate that more than 60% of human genes undergo alternative splicing with a differential tissue distribution. More than 15% of human genetic diseases are associated to mutations in the consensus splice sites and disruption of splicing regulatory networks contributes to various diseases, including cancer. Among the best characterized splicing regulators is the polypyrimidine tract binding protein (PTB) and its paralog nPTB. Highly conserved in vertebrates, PTB has been implicated in several cellular process related to post-transcriptional regulation. In addition to the alternative splicing regulation, PTB is involved into polyadenylation, mRNA stability and initiation of translation. For the latter, several studies have described the PTB recruitment in IRES-mediated translation initiation or propagation of several viruses including hepatitis C virus and picornaviruses. To perform these functions PTB is regulated in its intracellular localization, shuttling between nucleus and cytoplasm. Tissue specific PTB isoforms and co-regulators, the ribonucleoproteins Raver 1 and 2, have been recently identified. Mechanisms of post-transcriptional regulation mediated by PTB, nPTB and Raver proteins are described in the present review
EXPRESSION OF THE ALTERNATIVE SPLICING REGULATORS PTB AND RAVER DURING SKELETAL MUSCLE DIFFERENTIATION.
No full textRaver1 expression and alternative splicing events during skeletal muscle differentiation
No full textAn Open View on SARS-CoV-2 Infection
No full text: The onset of the SARS-CoV-2 virus led to the appearance of a devastating pandemic, which once again demonstrated the practical importance of virology [...]
Introductory Chapter: Malaria in 2022 – Promises and Unmet Needs
No full textIn this chapter were described: biological cycle of Plasmodia and diagnostic assays for malaria: microscopic examination, Rapid Diagnostic Test (RDT) based on antigen, Indirect Fluorescent Antibody Test (IFA test), and also, recently introduced and accepted, the nucleic-acid detection method by PCR or LAMP technologie
Isolation and genome characterization of a Klebsiella pneumoniae clinical strain carrying blaNDM-5 and blaOXA-48 isolated in Italy
No full text: Carbapenemase-producing Enterobacteriales (CPE) represent an emerging threat for global public health and a serious problem for clinicians due to the limited available treatment options. The emergence of CPE has been recently described worldwide by describing different antimicrobial mechanisms. Here, we describe a CPE carrying dual-carbapenemase isolated in Italy and we provide a deep characterization of the antimicrobial resistance genes, virulence-factors and prophage regions within the genome
RBM20 role in FHOD3 alternative splicing regulation
No full textRNA Binding Motif 20 is an RNA-binding protein acting as a regulator of mRNA splicing of a subset of expressed genes that play a key role in cardiac function. Mutations in the RBM2 gene are linked to familial dilated cardiomyopathy. The aim of this study is to analyze the functional role ofRBM20 protein in splicing regulation. we selected the “Formin Homology 2 Domain containing protein 3” (FHOD3) gene as a molecular target for RBM20 splicing regulation. Weapplied bioinformatics analysis in order to identify the putative cis -regulatory splicing signalsrequired for FHOD3 alternative transcripts expression. The results located potential consensus sequences for binding of RNA binding proteins in the exon-intron boundaries of 11-12-13 exons of the FHOD3 transcripts. Based on this information we are developing a FHOD3minigene that will be tested in transfected cells for functional analysis of RBM20. We expect that this molecular tool will help to elucidate the mechanism of alternative splicing mediated by tissue-specific ribonucleoproteins and will contribute to clarify the molecular pathogenesis of familiar dilated cardiomyopath
Genomic characterization of a high pathogenic Escherichia coli causing bacterial meningitis in a newborn in Italy, 2022: E. coli neonatal meningitis
No full text: Here, we characterize the complete genome sequence of Escherichia coli isolated from a newborn affected by bacterial meningitis in Italy. Genome of E. coli strain 1455 harbored a circular chromosome and two plasmids of 167.740-bp and 4.073-bp in length, respectively. E. coli 1455 belonged to the ST3, serotype O17:H18 and carried different determinants including resistance to B-lactams, tetracyclines, and quinolones. In addition, genome of E. coli strain 1455 harbored 5 integrated pro-phage regions mainly located in the chromosome, while most of the virulence factors associated to the invasiveness and clinical severity and different antimicrobial resistance determinants (blaTEM-1, tet(A) and qnrS1) were located in the 167-Kb plasmid. Taken together, our findings suggest a possible widespread of a virulence factors-carrying plasmid worldwide and highlight the importance of genomic characterization in the diffusion of public health threats
New insights into functional roles of the polypyrimidine tract-binding protein.
No full textPolypyrimidine Tract Binding Protein (PTB) is an intensely studied RNA binding protein involved in several post-transcriptional regulatory events of gene expression. Initially described as a pre-mRNA splicing regulator, PTB is now widely accepted as a multifunctional protein shuttling between nucleus and cytoplasm. Accordingly, PTB can interact with selected RNA targets, structural elements and proteins. There is increasing evidence that PTB and its paralog PTBP2 play a major role as repressors of alternatively spliced exons, whose transcription is tissue-regulated. In addition to alternative splicing, PTB is involved in almost all steps of mRNA metabolism, including polyadenylation, mRNA stability and initiation of protein translation. Furthermore, it is well established that PTB recruitment in internal ribosome entry site (IRES) activates the translation of picornaviral and cellular proteins. Detailed studies of the structural properties of PTB have contributed to our understanding of the mechanism of RNA binding by RNA Recognition Motif (RRM) domains. In the present review, we will describe the structural properties of PTB, its paralogs and co-factors, the role in post-transcriptional regulation and actions in cell differentiation and pathogenesis. Defining the multifunctional roles of PTB will contribute to the understanding of key regulatory events in gene expression
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