Modified nucleotides at the 5′ end of human U2 snRNA are required for spliceosomal E-complex formation

Dönmez, Gizem; Hartmuth, Klaus; Lührmann, Reinhard

doi:10.1261/rna.7186504

Cited by 120 publications

(127 citation statements)

References 41 publications

Supporting

Mentioning

123

Contrasting

Unclassified

Order By: Relevance

“…Later work carried out by the Luhrmann group looked into the role that pseudouridines of mammalian U2 snRNA play in pre-mRNA splicing in Hela cell extracts (Donmez et al, 2004). Their results confirmed that pseudouridines are required for the formation of early spliceosomal complexes; U2 lacking pseudouridine residues was found incompetent at forming complexes A, B1, B2, and C (Fig.…”

Section: Pseudouridylation Of U2 Is Required For Snrnp Assemblymentioning

confidence: 78%

Pseudouridines in spliceosomal snRNAs

2011

Protein Cell

View full text Add to dashboard Cite

Spliceosomal RNAs are a family of small nuclear RNAs (snRNAs) that are essential for pre-mRNA splicing. All vertebrate spliceosomal snRNAs are extensively pseudouridylated after transcription. Pseudouridines in spliceosomal snRNAs are generally clustered in regions that are functionally important during splicing. Many of these modified nucleotides are conserved across species lines. Recent studies have demonstrated that spliceosomal snRNA pseudouridylation is catalyzed by two different mechanisms: an RNA-dependent mechanism and an RNA-independent mechanism. The functions of the pseudouridines in spliceosomal snRNAs (U2 snRNA in particular) have also been extensively studied. Experimental data indicate that virtually all pseudouridines in U2 snRNA are functionally important. Besides the currently known pseudouridines (constitutive modifications), recent work has also indicated that pseudouridylation can be induced at novel positions under stress conditions, thus strongly suggesting that pseudouridylation is also a regulatory modification.

show abstract

Section: Pseudouridylation Of U2 Is Required For Snrnp Assemblymentioning

confidence: 78%

Pseudouridines in spliceosomal snRNAs

2011

Protein Cell

View full text Add to dashboard Cite

show abstract

“…When modeled with RNA oligomers, the presence of ⌿ in U2 small nuclear RNA causes a change in the structure of the lariat branch point of pre-messenger RNA (35,36). A functional requirement for ⌿ in U2 small nuclear RNA has also been shown in reconstitution of splicing systems (37)(38)(39). The loss of ⌿ in tRNAs may alter the structure of the tRNA and have an impact on its role in the translation process.…”

Section: Discussionmentioning

confidence: 99%

Mitochondrial Myopathy and Sideroblastic Anemia (MLASA)

Patton

Bykhovskaya

Mengesha

et al. 2005

Journal of Biological Chemistry

117

View full text Add to dashboard Cite

A missense mutation in the PUS1 gene affecting a highly conserved amino acid has been associated with mitochondrial myopathy and sideroblastic anemia (MLASA), a rare autosomal recessive oxidative phosphorylation disorder. The PUS1 gene encodes the enzyme pseudouridine synthase 1 (Pus1p) that is known to pseudouridylate tRNAs in other species. Total RNA was isolated from lymphoblastoid cell lines established from patients, parents, unaffected siblings, and unrelated controls, and the tRNAs were assayed for the presence of pseudouridine (⌿) at the expected positions. Mitochondrial and cytoplasmic tRNAs from MLASA patients are lacking modification at sites normally modified by Pus1p, whereas tRNAs from controls, unaffected siblings, or parents all have ⌿ at these positions. In addition, there was no Pus1p activity in an extract made from a cell line derived from a patient with MLASA. Immunohistochemical staining of Pus1p in cell lines showed nuclear, cytoplasmic, and mitochondrial distribution of the protein, and there is no difference in staining between patients and unaffected family members. MLASA is thus associated with absent or greatly reduced tRNA pseudouridylation at specific sites, implicating this pathway in its molecular pathogenesis.Following transcription, all stable RNAs are processed, and nucleotides are modified. The most abundant modification is pseudouridine (⌿), formed by the action of pseudouridine synthases. A number of these modification enzymes have been characterized from several species, and one that has been particularly well studied is pseudouridine synthase 1 (Pus1p).

show abstract

“…All snRNAs are capped at their 5′ ends by TMG, and internal bases are modified by scaRNAs present in the CB 7 . Internally modified nucleotides are required for U2 snRNP function, whereas the TMG cap is not 38 . Therefore, we tested modified U1 and U2 snRNAs purified from mature human snRNPs in our assay ( Supplementary Fig.…”

Section: Mature Human Spliceosomal Snrnps Rescue the Coilin Morphantmentioning

confidence: 99%

Coilin-dependent snRNP assembly is essential for zebrafish embryogenesis

Strzelecka

Trowitzsch

Weber

et al. 2010

Nat Struct Mol Biol

Self Cite

147

164

View full text Add to dashboard Cite

0 3 a r t i c l e sIn eukaryotes, organelles delimited by lipid bilayers support the organization of cellular functions, as exemplified by the segregation of chromatin into the cell nucleus. However, many subcellular compartments-nucleoli, Cajal and PML bodies, polar granules, stress granules, P bodies and others-lack membranes. How these structures contribute to cellular physiology is largely unknown 1 . The Cajal body (CB) is a 0.5-to 1-µm nuclear compartment initially described by Ramon y Cajal in silver-stained sections of vertebrate cerebral cortex 2 . Because the CB is conserved in evolution and is uniquely marked by the protein coilin, it has served as a general model for subnuclear structure and function 1,2 . Numerous factors essential for pre-mRNA splicing, histone mRNA 3′-end processing, telomere maintenance and rRNA processing are concentrated in CBs. Yet CB components exchange rapidly with the nucleoplasm, where most of these processes occur 3 . The challenge, therefore, has been to identify the function of CBs.Despite the localization of splicing machinery in CBs, they are not the sites of pre-mRNA splicing 4,5 . Splicing occurs throughout the nucleus and is catalyzed by the spliceosome, a macromolecular complex formed on pre-mRNA from five essential snRNPs 6 . Each spliceosomal snRNP comprises a unique 100-to 200-nucleotide snRNA (U1, U2, U4, U5 and U6) that is post-transcriptionally modified and associated with a number of snRNP-specific proteins 6,7 . Several roles for CBs in spliceosomal snRNP biogenesis have been proposed based on the localization of specific steps in snRNP assembly in the CBs of cultured cell lines. After transcription and export to the cytoplasm, U1, U2, U4 and U5 snRNAs receive a heteroheptameric ring of Sm proteins assembled by the SMN complex; subsequently, their 5′ ends are hypermethylated 8 . The Sm ring and trimethylguanosine (TMG) cap are signals for snRNP reimport into the nucleus, where these still-immature core snRNPs first concentrate in CBs 9-12 . CBs contain scaRNAs, which then guide site-specific modification of the snRNAs 13 . Importantly, intermediates in the final snRNP maturation steps, reflecting RNA structural rearrangements and the recruitment of snRNP-specific proteins, are highly concentrated in CBs 14-17 . These observations have led to the proposal that CBs are the sites of snRNP assembly, but an essential role for CBs in this process has not been shown.The coilin protein may hold the key to CB function. Immunoelectron microscopy studies of CBs reveal thread-like, coilin-positive aggregates, suggesting that coilin is integral to CB structure 2 . Consistent with this, coilin resides longer in CBs than any other examined component in vivo 3,18 . Notably, depletion of coilin results in the dispersal of many CB components. Without coilin, spliceosomal factors become nucleoplasmic, and other classes of CB-localized factors (for example, SMN, fibrillarin and small Cajal body-specific RNAs (scaRNAs)) continue to self-associate in discrete 'residual bodies' ...

show abstract

Modified nucleotides at the 5′ end of human U2 snRNA are required for spliceosomal E-complex formation

Cited by 120 publications

References 41 publications

Pseudouridines in spliceosomal snRNAs

Pseudouridines in spliceosomal snRNAs

Mitochondrial Myopathy and Sideroblastic Anemia (MLASA)

Coilin-dependent snRNP assembly is essential for zebrafish embryogenesis

Contact Info

Product

Resources

About