Early recognition of pre-mRNA during spliceosome assembly in mammals proceeds through the association of U1 small nuclear ribonucleoprotein particle (snRNP) with the 5' splice site as well as the interactions of the branch binding protein SF1 with the branch region and the U2 snRNP auxiliary factor U2AF with the polypyrimidine tract and 3' splice site. These factors, along with members of the SR protein family, direct the ATP-independent formation of the early (E) complex that commits the pre-mRNA to splicing. We report here the observation in U2AF-depleted HeLa nuclear extract of a distinct, ATP-independent complex designated E' which can be chased into E complex and itself commits a pre-mRNA to the splicing pathway. The E' complex is characterized by a U1 snRNA-5' splice site base pairing, which follows the actual commitment step, an interaction of SF1 with the branch region, and a close association of the 5' splice site with the branch region. These results demonstrate that both commitment to splicing and the early proximity of conserved sequences within pre-mRNA substrates can occur in a minimal complex lacking U2AF, which may function as a precursor to E complex in spliceosome assembly.
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http://dx.doi.org/10.1128/MCB.25.1.233-240.2005 | DOI Listing |
Unlabelled: The maturation of RNA is mediated by the coordinated actions of RNA-binding proteins through post-transcriptional pre-mRNA processing. This process is a central regulatory mechanism for gene expression and plays a crucial role in the development of complex biological systems. MYC directly upregulates transcription of genes encoding the core components of pre-mRNA splicing machinery.
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Blood Group Reference Laboratory, Dalian Blood Center, Dalian, China.
Background: Mutations in the ABO gene, including base insertions, deletions, substitutions, and splicing errors, can result in blood group subgroups associated with the quantity and quality of blood group antigens. Here, we employed third-generation PacBio sequencing to uncover a novel allele arising from an intron splice site mutation, which altered the expected A phenotype to manifest as an Ael phenotype. The study aimed to characterize the molecular mechanism underlying this phenotypic switch.
View Article and Find Full Text PDFCell Death Dis
January 2025
Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, 60438, Frankfurt, Germany.
The transcription factor p63 is expressed in many different isoforms as a result of differential promoter use and splicing. Some of these isoforms have very specific physiological functions in the development and maintenance of epithelial tissues and surveillance of genetic integrity in oocytes. The ASPP family of proteins is involved in modulating the transcriptional activity of the p53 protein family members, including p63.
View Article and Find Full Text PDFAnn Med
December 2025
Department of Basic Medical Sciences, College of Medicine & Center for Genetics and Inherited Diseases, Taibah University Medina, Medina, Saudi Arabia.
Background: Peroxisome biogenesis disorders (PBD) affect multiple organ systems. It is characterized by neurological dysfunction, hypotonia, ocular anomalies, craniofacial abnormalities, and absence of peroxisomes in fibroblasts. PBDs are associated with mutations in any of fourteen different genes, which are involved in peroxisome biogenesis.
View Article and Find Full Text PDFEur J Hum Genet
January 2025
Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India.
Mitochondrial membrane protein-associated neurodegeneration (MPAN) is a rare neurodegenerative disorder characterized by spastic paraplegia, parkinsonism and psychiatric and/or behavioral symptoms caused by variants in gene encoding chromosome-19 open reading frame-12 (C19orf12). We present here seven patients from six unrelated families with detailed clinical, radiological, and genetic investigations. Childhood-onset patients predominantly had a spastic ataxic phenotype with optic atrophy, while adult-onset patients were presented with cognitive, behavioral, and parkinsonian symptoms.
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