scholarly journals Binding of CCCTC-Binding Factor (CTCF) to the Minute Virus of Mice Genome Is Important for Proper Processing of Viral P4-Generated Pre-mRNAs

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1368
Author(s):  
Maria Boftsi ◽  
Kinjal Majumder ◽  
Lisa R. Burger ◽  
David J. Pintel
Keyword(s):  
Chromatin Immunoprecipitation ◽  
Genome Organization ◽  
Dna Binding Protein ◽  
Minute Virus Of Mice ◽  
Cell Extracts ◽  
Binding Factor ◽  
Minute Virus ◽  
Definition Of ◽  
Novel Exon ◽  
Affect Processing

Specific chromatin immunoprecipitation of salt-fractionated infected cell extracts has demonstrated that the CCCTC-binding factor (CTCF), a highly conserved, 11-zinc-finger DNA-binding protein with known roles in cellular and viral genome organization and gene expression, specifically binds the genome of Minute Virus of Mice (MVM). Mutations that diminish binding of CTCF to MVM affect processing of the P4-generated pre-mRNAs. These RNAs are spliced less efficiently to generate the R1 mRNA, and definition of the NS2-specific exon upstream of the small intron is reduced, leading to relatively less R2 and the generation of a novel exon-skipped product. These results suggest a model in which CTCF is required for proper engagement of the spliceosome at the MVM small intron and for the first steps of processing of the P4-generated pre-mRNA.

scholarly journals Intron Definition Is Required for Excision of the Minute Virus of Mice Small Intron and Definition of the Upstream Exon

1998 ◽  
Vol 72 (3) ◽  
pp. 1834-1843 ◽  
Author(s):  
Donald D. Haut ◽  
D. J. Pintel
Keyword(s):  
Alternative Splicing ◽  
Consensus Sequence ◽  
Critical Role ◽  
Viral Mrnas ◽  
Minute Virus Of Mice ◽  
Natural Context ◽  
Minute Virus ◽  
Definition Of ◽  
Intron Definition ◽  
Upstream Exon

ABSTRACT Alternative splicing of pre-mRNAs plays a critical role in maximizing the coding capacity of the small parvovirus genome. The small-intron region of minute virus of mice (MVM) pre-mRNAs undergoes an unusual pattern of overlapping alternative splicing—using two donors (D1 and D2) and two acceptors (A1 and A2) within a region of 120 nucleotides—that determines the steady-state ratios of the various viral mRNAs. In this report, we show that the determinants that govern excision of the small intron are complex and are also required for efficient definition of the upstream exon. For the MVM small intron in its natural context, the two donors appear to compete for the splicing machinery: the position of D1 favors its usage, while the primary sequence of D2 must be more like the consensus sequence than is D1 to be used efficiently. We have genetically defined the branch points that are used for generation of the major and minor spliced forms and show that recognition of components of the small-intron acceptors is likely to be the dominant determinant in alternative small-intron excision. We have also identified a G-rich intronic enhancer sequence within the small intron that is essential for splicing of the minor form (D2 to A2) but not the major form (D1 to A1) of MVM mRNAs and is required for efficient definition of the upstream NS2-specific exon. In its natural context, the small intron appears to be excised by a mechanism consistent with intron definition. When the MVM small intron is expanded, various parameters of its excision are altered, indicating that critical cis-acting signals are context dependent. Relative use of the donors and acceptors is altered, and the upstream NS2-specific exon is no longer efficiently defined. The fact that definition of the upstream NS2-specific exon can be achieved by the MVM small intron in its natural context, but not when it is expanded, suggests that the multiple determinants that govern definition and excision of the small intron are required, in concert, for upstream exon definition. Our data are consistent with a model in which alternative splicing of the MVM P4-generated pre-mRNAs is governed by a hybrid of intron- and exon-defining mechanisms.

A precise map of splice junctions in the mRNAs of minute virus of mice, an autonomous parvovirus.

1986 ◽  
Vol 59 (3) ◽  
pp. 564-573 ◽  
Author(s):  
C V Jongeneel ◽  
R Sahli ◽  
G K McMaster ◽  
B Hirt
Keyword(s):  
Minute Virus Of Mice ◽  
Minute Virus ◽  
Splice Junctions

Gene insulation. Part II: natural strategies in vertebrates

2010 ◽  
Vol 88 (6) ◽  
pp. 885-898 ◽  
Author(s):  
Michèle Amouyal
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Protein Interactions ◽  
Dna Looping ◽  
Chromatin Domain ◽  
Trna Genes ◽  
Binding Factor ◽  
Genomic Environment ◽  
Nuclear Structures ◽  
Definition Of

The way a gene is insulated from its genomic environment in vertebrates is not basically different from what is observed in yeast and Drosophila (preceding article in this issue). If the formation of a looped chromatin domain, whether generated by attachment to the nuclear matrix or not, has become a classic way to confine an enhancer to a specific genomic domain and to coordinate, sequentially or simultaneously, gene expression in a given program, its role has been extended to new networks of genes or regulators within the same gene. A wider definition of the bases of the chromatin loops (nonchromosomal nuclear structures or genomic interacting elements) is also available. However, whereas insulation in Drosophila is due to a variety of proteins, in vertebrates insulators are still practically limited to CTCF (the CCCTC-binding factor), which appears in all cases to be the linchpin of an architecture that structures the assembly of DNA–protein interactions for gene regulation. As in yeast and Drosophila, the economy of means is the rule and the same unexpected diversion of known transcription elements (active or poised RNA polymerases, TFIIIC elements out of tRNA genes, permanent histone replacement) is observed, with variants peculiar to CTCF. Thus, besides structuring DNA looping, CTCF is a barrier to DNA methylation or interferes with all sorts of transcription processes, such as that generating heterochromatin.

Parvovirus infection in children and pregnant women

2021 ◽  
Vol 19 (2) ◽  
pp. 119-125
Author(s):  
E.V. Mikhailova ◽  
◽  
T.K. Chudakova ◽  
D.Yu. Levin ◽  
A.V. Romanovskaya ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Ex Vivo ◽  
Parvovirus B19 ◽  
Virus Transmission ◽  
Intrauterine Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Minute Virus Of Mice ◽  
Gestation Age ◽  
B19 Parvovirus ◽  
Minute Virus

Parvovirus (PV) is a widespread infection, despite the fact that this pathogen was discovered only recently. The therapeutic effect of PV, in particular its oncolytic activity, is being actively studied now. Notably, PVs causing infections in animals, such as rat PV H-1, caninae PV, and rodent protoparvovirus (minute virus of mice) suppress oncogenesis in these animals. There is an ex vivo evidence of rat glioblastoma and gliosarcoma sensitivity to PV. The affinity of PV B19 to P-antigen located primarily on the membranes of erythroid cells is crucial for the disease pathogenesis. The teratogenic effect of PV B19 is associated with its ability to infect placental cells (P-antigen is present on the cells of chorionic villi and surface of the trophoblast). PV infection can be acquired or congenital, typical or atypical. The outcome of intrauterine infection with PV B19 largely depends on the gestation age when the infection occurred. Women infected during the second trimester are at higher risk of vertical transmission and severe intrauterine pathology with a poor outcome than those infected during the third trimester. Constant contact with young children significantly increases the risk of PV B19 infection among pregnant women with no immunity to this virus. Serum is the most convenient biomaterial for detecting both PV DNA and virus-specific antibodies. One test for anti-PV IgG using enzyme-linked immunosorbent assay is sufficient to determine the immune status of a patient. Polymerase chain reaction with amniotic fluid is used to diagnose intrauterine infection with PV B19. Blood components and products should be checked for PV B19. High frequency of PV B19 detection in the blood of donors necessitates the development of special measures aimed at prevention of virus transmission. Key words: pregnant women, children, parvovirus B19, parvovirus infection

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