scholarly journals 3'-End processing of histone pre-mRNAs in Drosophila: U7 snRNP is associated with FLASH and polyadenylation factors

RNA ◽  
2013 ◽  
Vol 19 (12) ◽  
pp. 1726-1744 ◽  
Author(s):  
I. Sabath ◽  
A. Skrajna ◽  
X.-c. Yang ◽  
M. Dadlez ◽  
W. F. Marzluff ◽  
...  
Keyword(s):  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ankur Gadgil ◽  
Agnieszka Walczak ◽  
Agata Stępień ◽  
Jonas Mechtersheimer ◽  
Agnes Lumi Nishimura ◽  
...  

AbstractGenes encoding replication-dependent histones lack introns, and the mRNAs produced are a unique class of RNA polymerase II transcripts in eukaryotic cells that do not end in a polyadenylated tail. Mature mRNAs are thus formed by a single endonucleolytic cleavage that releases the pre-mRNA from the DNA and is the only processing event necessary. U7 snRNP is one of the key factors that determines the cleavage site within the 3ʹUTR of replication-dependent histone pre-mRNAs. We have previously showed that the FUS protein interacts with U7 snRNA/snRNP and regulates the expression of histone genes by stimulating transcription and 3ʹ end maturation. Mutations in the FUS gene first identified in patients with amyotrophic lateral sclerosis (ALS) lead to the accumulation of the FUS protein in cytoplasmic inclusions. Here, we report that mutations in FUS lead to disruption of the transcriptional activity of FUS and mislocalization of U7 snRNA/snRNP in cytoplasmic aggregates in cellular models and primary neurons. As a consequence, decreased transcriptional efficiency and aberrant 3ʹ end processing of histone pre-mRNAs were observed. This study highlights for the first time the deregulation of replication-dependent histone gene expression and its involvement in ALS.


2016 ◽  
Vol 213 (5) ◽  
pp. 557-570 ◽  
Author(s):  
Deirdre C. Tatomer ◽  
Esteban Terzo ◽  
Kaitlin P. Curry ◽  
Harmony Salzler ◽  
Ivan Sabath ◽  
...  

The histone locus body (HLB) assembles at replication-dependent histone genes and concentrates factors required for histone messenger RNA (mRNA) biosynthesis. FLASH (Flice-associated huge protein) and U7 small nuclear RNP (snRNP) are HLB components that participate in 3′ processing of the nonpolyadenylated histone mRNAs by recruiting the endonuclease CPSF-73 to histone pre-mRNA. Using transgenes to complement a FLASH mutant, we show that distinct domains of FLASH involved in U7 snRNP binding, histone pre-mRNA cleavage, and HLB localization are all required for proper FLASH function in vivo. By genetically manipulating HLB composition using mutations in FLASH, mutations in the HLB assembly factor Mxc, or depletion of the variant histone H2aV, we find that failure to concentrate FLASH and/or U7 snRNP in the HLB impairs histone pre-mRNA processing. This failure results in accumulation of small amounts of polyadenylated histone mRNA and nascent read-through transcripts at the histone locus. Thus, the HLB concentrates FLASH and U7 snRNP, promoting efficient histone mRNA biosynthesis and coupling 3′ end processing with transcription termination.


RNA ◽  
2017 ◽  
Vol 23 (6) ◽  
pp. 938-951 ◽  
Author(s):  
Aleksandra Skrajna ◽  
Xiao-cui Yang ◽  
Katarzyna Bucholc ◽  
Jun Zhang ◽  
Traci M. Tanaka Hall ◽  
...  

1991 ◽  
Vol 23 (10) ◽  
pp. 1049-1052 ◽  
Author(s):  
G. Pironcheva ◽  
G. Russev
Keyword(s):  

2008 ◽  
Vol 29 (1) ◽  
pp. 31-42 ◽  
Author(s):  
Xiao-cui Yang ◽  
Kelly D. Sullivan ◽  
William F. Marzluff ◽  
Zbigniew Dominski

ABSTRACT Processing of histone pre-mRNA requires a single 3′ endonucleolytic cleavage guided by the U7 snRNP that binds downstream of the cleavage site. Following cleavage, the downstream cleavage product (DCP) is rapidly degraded in vitro by a nuclease that also depends on the U7 snRNP. Our previous studies demonstrated that the endonucleolytic cleavage is catalyzed by the cleavage/polyadenylation factor CPSF-73. Here, by using RNA substrates with different nucleotide modifications, we characterize the activity that degrades the DCP. We show that the degradation is blocked by a 2′-O-methyl nucleotide and occurs in the 5′-to-3′ direction. The U7-dependent 5′ exonuclease activity is processive and continues degrading the DCP substrate even after complete removal of the U7-binding site. Thus, U7 snRNP is required only to initiate the degradation. UV cross-linking studies demonstrate that the DCP and its 5′-truncated version specifically interact with CPSF-73, strongly suggesting that in vitro, the same protein is responsible for the endonucleolytic cleavage of histone pre-mRNA and the subsequent degradation of the DCP. By using various RNA substrates, we define important space requirements upstream and downstream of the cleavage site that dictate whether CPSF-73 functions as an endonuclease or a 5′ exonuclease. RNA interference experiments with HeLa cells indicate that degradation of the DCP does not depend on the Xrn2 5′ exonuclease, suggesting that CPSF-73 degrades the DCP both in vitro and in vivo.


2021 ◽  
Author(s):  
Moataz Dowaidar

In 1968, Weinberg and Penman initially coined the term snRNA. Splicing is the process of eliminating introns from pre-RNA and combining exons The two forms of splicing are constitutive and alternative. U7 snRNP is a critical element in the unique 3′ end processing of replication-dependent histone (RDH) premRNAs. U7 Sm OPT uses antisense oligonucleotides to control pre-mRNA splicing. U7 snRNP has shown potential in preclinical studies and human clinical trials. DMD, ALS, thalassemia, HIV-1 infection, and spinal muscular atrophy are excellent illustrations of the majority of the problems (SMA) SmD1 and SmD2, which are found in other U snRNPs, are replaced by Lsm10 and Lsm11, respectively. There are just 500 molecules of U7SnRNP in a cell. Interesting because of its size, great stability, and tendency to collect in the nucleus of U 7 snRNA. The snRNP particle may hybridize to practically any RNA sequence in the nucleoplasm by altering the motif.U7 snRNA gene therapy is often employed to repair splicing abnormalities. The utilization of U7 Sm OPT-implanted antisense oligonucleotides has a multitude of potential therapeutic applications. More effective are the locations that bind U1 and U2 snRNPs to suppress splicing. useful for addressing splicing mistakes in muscular dystrophy, DMD, ALS, thalassemia, HIV-1 infection, and SMA PTCH1, BRCA1, and CYP11A have all been fixed with it. X-linked recessive muscular wasting illness, DMD. Individuals with exon 2 deletions either have asymptomatic or mildly symptomatic dystrophin levels. ANTISENSE oligonucleotides were introduced into the U7 Sm OPT and given via AAV to treat patients. These cells missed exon 2, resulting in an alternative translation starting at exon 6. (through an internal ribosome entrance region) The NIH's next clinical study will commence in January of 2020. U7 Sm OPT bifunctional gene therapy was successful in treating muscular dystrophy.Superoxide dismutase 1 (SOD1) gene mutations cause amyotrophic lateral sclerosis (ALS). SOD1 function was restored in a single study using U7Sm OPT to help rats with ALS. When given at birth, this medicine postponed sickness onset and enhanced life expectancy by 92% and 58%, respectively. Mutations in intron 2 produce a premature stop codon and hinder translation of full-length globin. Antisense oligonucleotides that span this region target nucleotides 102 to 130 of globin mRNA exon 1.5′ or 3′ splice site oligonucleotides in mammalian cells have been found to fix globin mRNA. The 654T > G mutation causes severe thalassemia symptoms. Combining U7 Sm OPT with induced pluripotent stem cells (iPSCs) led to a successful decrease of the globin gene


1988 ◽  
Vol 8 (3) ◽  
pp. 1076-1084
Author(s):  
G M Gilmartin ◽  
F Schaufele ◽  
G Schaffner ◽  
M L Birnstiel

U7 small nuclear RNA (snRNA) is an essential component of the RNA-processing machinery which generates the 3' end of mature histone mRNA in the sea urchin. The U7 small nuclear ribonucleoprotein particle (snRNP) is classified as a member of the Sm-type U snRNP family by virtue of its recognition by both anti-trimethylguanosine and anti-Sm antibodies. We analyzed the function-structure relationship of the U7 snRNP by mutagenesis experiments. These suggested that the U7 snRNP of the sea urchin is composed of three important domains. The first domain encompasses the 5'-terminal sequences, up to about nucleotides 7, which are accessible to micrococcal nuclease, while the remainder of the RNA is highly protected and hence presumably bound by proteins. This region contains the sequence complementarities between the U7 snRNA and the histone pre-mRNA which have previously been shown to be required for 3' processing (F. Schaufele, G. M. Gilmartin, W. Bannwarth, and M. L. Birnstiel, Nature [London] 323:777-781, 1986). Nucleotides 9 to 20 constitute a second domain which includes sequences for Sm protein binding. The complementarities between the U7 snRNA sequences in this region and the terminal palindrome of the histone mRNA appear to be fortuitous and play only a secondary, if any, role in 3' processing. The third domain is composed of the terminal palindrome of U7 snRNA, the secondary structure of which must be maintained for the U7 snRNP to function, but its sequence can be drastically altered without any observable effect on snRNP assembly or 3' processing.


2019 ◽  
Vol 48 (3) ◽  
pp. 1508-1530 ◽  
Author(s):  
Katarzyna Bucholc ◽  
Wei Shen Aik ◽  
Xiao-cui Yang ◽  
Kaituo Wang ◽  
Z Hong Zhou ◽  
...  

Abstract In animal cells, replication-dependent histone pre-mRNAs are cleaved at the 3′ end by U7 snRNP consisting of two core components: a ∼60-nucleotide U7 snRNA and a ring of seven proteins, with Lsm10 and Lsm11 replacing the spliceosomal SmD1 and SmD2. Lsm11 interacts with FLASH and together they recruit the endonuclease CPSF73 and other polyadenylation factors, forming catalytically active holo U7 snRNP. Here, we assembled core U7 snRNP bound to FLASH from recombinant components and analyzed its appearance by electron microscopy and ability to support histone pre-mRNA processing in the presence of polyadenylation factors from nuclear extracts. We demonstrate that semi-recombinant holo U7 snRNP reconstituted in this manner has the same composition and functional properties as endogenous U7 snRNP, and accurately cleaves histone pre-mRNAs in a reconstituted in vitro processing reaction. We also demonstrate that the U7-specific Sm ring assembles efficiently in vitro on a spliceosomal Sm site but the engineered U7 snRNP is functionally impaired. This approach offers a unique opportunity to study the importance of various regions in the Sm proteins and U7 snRNA in 3′ end processing of histone pre-mRNAs.


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