We present for the first time experimental evidence that in vitro synthesized RNA (cRNA) is trans-spliced after microinjection into the nuclei of mammalian tissue culture cells. The template used for cRNA synthesis was the early SV40 BstXl/BamHI DNA fragment. This DNA fragment encodes exclusively for the second T-antigen exon and contains the intact small t-antigen intron. To generate the corresponding mRNA (T1-mRNA) by trans-splicing, the cells utilize a 5' cryptic splice site located within the second T-antigen exon of one cRNA molecule which is spliced to the small t-antigen 3' splice site of another cRNA molecule. Formation of the T1-mRNA by trans-splicing was confirmed by RT-PCR analysis and DNA sequencing. Efficient trans-splicing required that competitive small t-antigen cis-splicing be inhibited by deletion of the small t-antigen 5' splice site. The T1-mRNA was not generated when the cryptic 5' splice site was mutated.
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http://dx.doi.org/10.1016/0014-5793(96)00957-x | DOI Listing |
Int J Mol Sci
January 2025
Clinical Division of General Anaesthesia and Intensive Care Medicine, Department of Anesthesia, Genera Intensive Care and Pain Therapy, Medical University Vienna, 1090 Vienna, Austria.
Drug development for human disease relies on preclinical model systems such as human cell cultures and animal experiments before therapeutic treatments can ultimately be tested on humans in clinical studies. We here describe the generation of a novel human cell line (HLMVEC/SVTERT289) that we generated by transfection of microvascular endothelial cells from healthy donor lung tissue with the catalytic domain of telomerase and the SV40 large T/small t-antigen. These cells exhibited satisfactory growth characteristics and largely maintained their native characteristics, including morphology, cell surface marker expression, angiogenic potential and the protein composition of secreted extracellular vesicles.
View Article and Find Full Text PDFTzu Chi Med J
December 2024
Department of Obstetrics and Gynecology, College of Medicine, University of Babylon, Hilla, Iraq.
The most common STD that triggers cervical cancer is the human papillomavirus. More than 20 types of human papillomavirus (HPV) can induce uterine cervical cancer. Almost all women acquire genital HPV infection soon after their first intercourse, with most of them clearing the virus within 3 years.
View Article and Find Full Text PDFPLoS Genet
January 2025
Biomedical Science Graduate Program, University of California San Diego, San Diego, California, United States of America.
Proteins with nuclear localization sequences (NLSs) are directed into the cell nucleus through interactions between the NLS and importin proteins. NLSs are generally short motifs rich in basic amino acids; however, identifying NLSs can be challenging due to the lack of a universally conserved sequence. In this study, we characterized the sequence specificity of an essential and conserved NLS in Mcm3, a subunit of the replicative DNA helicase.
View Article and Find Full Text PDFJ Med Virol
January 2025
The Wistar Institute, Philadelphia, Pennsylvania, USA.
Epstein-Barr virus (EBV) is a ubiquitous human ɣ-herpesvirus implicated in various malignancies, including Burkitt's lymphoma and gastric carcinomas. In most EBV-associated cancers, the viral genome is maintained as an extrachromosomal episome by the EBV nuclear antigen-1 (EBNA1). EBNA1 is considered to be a highly stable protein that interacts with the ubiquitin-specific protease 7 (USP7).
View Article and Find Full Text PDFVaccines (Basel)
December 2024
Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering, University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606, USA.
Background/objectives: The MHCII-dependent, CD4+ T-cell zwitterionic polysaccharide PS A1 has been investigated as a promising carrier for vaccine development because it can induce an MHCII-dependent CD4+ response towards a variety of tumor-associated carbohydrate antigens (TACAs). However, PS A1 cannot elicit cytotoxic T lymphocytes through MHCI, which may or may not hamper its potential clinical use in cancer, infectious and viral vaccine development. This paper addresses PS A1 MHCI independence through the introduction of an MHCI epitope, the poliovirus (PV) peptide, to establish an MHCI- and MHCII-dependent vaccine.
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