Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Targeted high throughput mutagenesis of the human spliceosome reveals its in vivo operating principles [screen]

ABSTRACT: A major impediment to studying the human spliceosome in vivo has been the inability to program point mutations in endogenous genes on a large scale. CRISPR-Cas9 technology now provides such opportunities. Due to its scalability and ability to introduce point mutations, we chose CRISPR-Cas9 base editing for a forward genetic screen of the spliceosome in an eHAP haploid human cell line background. We maintained eHAP FNLS cells as haploid so that we could subsequently assign genotype-phenotype relationships. We designed a single guide RNA (sgRNA) library targeting a hand-curated list of 153 human spliceosomal proteins which engage at various steps of the splicing cycle. After mutagenesis, we interrogated the spliceosome using the potent inhibitor pladienolide B (PB), which targets U2 snRNP by binding to a pocket between the SF3B1 and PHF5A subunits of the SF3b complex, preventing stabilization of the U2-branchpoint RNA duplex. Validation and genomic sequencing revealed resistance mutations in SF3B1 and PHF5A in residues adjacent to the compound binding pocket. We mapped hypersensitive mutants to U2 snRNP components, but also to factors that act as late as the second chemical step, after SF3b has dissociated. Strikingly, we obtained resistance mutants in SUGP1, a spliceosomal G-patch protein of unknown function that lacks orthologs in yeast and is also a newly proposed tumor suppressor whose loss underpins the splicing changes induced by cancer-associated SF3B1 mutations.

ORGANISM(S): Homo sapiens

PROVIDER: GSE218306 | GEO | 2023/07/07

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Targeted high throughput mutagenesis of the human spliceosome reveals its in vivo operating principles [editing]

Project description:A major impediment to studying the human spliceosome in vivo has been the inability to program point mutations in endogenous genes on a large scale. CRISPR-Cas9 technology now provides such opportunities. Due to its scalability and ability to introduce point mutations, we chose CRISPR-Cas9 base editing for a forward genetic screen of the spliceosome in an eHAP haploid human cell line background. We maintained eHAP FNLS cells as haploid so that we could subsequently assign genotype-phenotype relationships. We designed a single guide RNA (sgRNA) library targeting a hand-curated list of 153 human spliceosomal proteins which engage at various steps of the splicing cycle. After mutagenesis, we interrogated the spliceosome using the potent inhibitor pladienolide B (PB), which targets U2 snRNP by binding to a pocket between the SF3B1 and PHF5A subunits of the SF3b complex, preventing stabilization of the U2-branchpoint RNA duplex. Validation and genomic sequencing revealed resistance mutations in SF3B1 and PHF5A in residues adjacent to the compound binding pocket. We mapped hypersensitive mutants to U2 snRNP components, but also to factors that act as late as the second chemical step, after SF3b has dissociated. Strikingly, we obtained resistance mutants in SUGP1, a spliceosomal G-patch protein of unknown function that lacks orthologs in yeast and is also a newly proposed tumor suppressor whose loss underpins the splicing changes induced by cancer-associated SF3B1 mutations.

2023-07-07 | GSE218305 | GEO

Targeted high throughput mutagenesis of the human spliceosome reveals its in vivo operating principles [RNA-Seq]

2023-07-07 | GSE218304 | GEO

Overlapping roles of spliceosomal components SF3B1 and PHF5A in rice splicing regulation

Project description:The SF3B complex, a multiprotein component of the U2 snRNP of the spliceosome, mediates branch point selection and facilitates spliceosome assembly and activation. Several splicing modulators bind the SF3B1 and PHF5A subunits of the SF3B complex and globally inhibit splicing. Engineered mutant variants of SF3B1 and PHF5A conferred tolerance to splicing inhibitors with only minor effects on gene expression and AS.

2021-04-11 | GSE153234 | GEO

Splicing Modulators Act at the Branch Point Adenosine Binding Pocket Defined by the PHF5A-SF3b Complex

Project description:Developing small-molecule splicing modulators represents a promising therapeutic approach for various diseases. Natural products such as pladienolide, herboxidiene, and spliceostatin have been identified as potent splicing modulators that target SF3B1 in the SF3b subcomplex. Using integrated chemogenomic, structural and biochemical approaches, we show that PHF5A, another core component of the SF3b complex, is also targeted by these compounds. Mutations in PHF5A-Y36, SF3B1-K1071, SF3B1-R1074, and SF3B1-V1078 confer resistance to these modulators, suggesting a common site of interaction. Whole-transcriptome RNA-seq analysis reveals that PHF5A-Y36C has minimal effect on basal splicing but alters the action of splicing modulators from inducing intron-retention to exon-skipping. Relative intron strength to splicing inhibition correlates with the differential in GC content between adjacent introns and exons, leading to this differential global splicing pattern. We determine the crystal structure of human PHF5A and find that Y36 is located on the surface in a region of high sequence conservation. Structural analysis of the cryo-EM spliceosome Bact complex shows that these mutations cluster in a well-defined pocket surrounding the branch point adenosine suggesting a possible competitive mode of action for these splicing modulators, which interact with the aromatic side-chain of PHF5A-Y36. Collectively, we propose that PHF5A-SF3B1 forms a central node for binding to these small-molecule splicing modulators, offering insights to modulate splicing.

2017-05-25 | GSE96917 | GEO

H3B-8800, a novel oral splicing modulator, induces lethality in spliceosome mutant cancers [K562]

Project description:Genomic analyses of cancer have identified recurrent point mutations in the RNA splicing factors SF3B1, U2AF1, and SRSF2 that confer an alteration of function. Although cells bearing these mutations are preferentially dependent on wild-type (WT) spliceosome function, clinical means to therapeutically target the spliceosome do not currently exist. Here, we describe an orally available modulator of the SF3b complex, H3B-8800, which potently and selectively kills spliceosome-mutant epithelial and hematologic malignancies. The effects of H3B-8800 are entirely selective for the Sf3b complex, as evidenced by the identification of drug-resistant cells bearing mutations in Sf3b components. Although H3B-8800 modulates RNA splicing mediated by WT or cancer-associated SF3B1 mutants, its preferential effects on spliceosome-mutant cells is due to preferred retention of short, GC-rich introns, which are enriched in genes encoding a substantial number of spliceosome components. These data demonstrate the therapeutic potential of splicing modulation in spliceosome-mutant cancers.

2017-12-20 | GSE94528 | GEO

H3B-8800, a novel oral splicing modulator, induces lethality in spliceosome mutant cancers [Nalm-6]

2017-12-20 | GSE94999 | GEO

CDK11 phosphorylates SF3B1 and is essential for constitutive splicing (ChIP-seq)

Project description:Pre-mRNA splicing is a highly regulated process catalyzing intron excision by spliceosome. Spliceosome activation is a major control step requiring dramatic protein and RNA rearrangements leading to a catalytically active complex. Prior research has linked hyperphosphorylation of SF3B1, a subunit of U2 snRNP, with spliceosome activation and catalytically active spliceosome, rendering a relevant kinase a key player for pre-mRNA splicing. Here we use OTS964, the first potent inhibitor of cyclin-dependent kinase 11 (CDK11), to show rapid and selective dephosphorylation of SF3B1 on threonines required for spliceosome activation. CDK11 associates with SF3B1 and its inhibition causes massive intron retention, block in precatalytic spliceosome complex B to activated spliceosome complex Bact transition and accumulation of non-functional spliceosomes on pre-mRNA and chromatin. These studies reveal crucial regulatory role of CDK11 in human pre-mRNA splicing and define the compound OTS964 as a quality chemical biology probe for CDK11.

2022-07-09 | GSE185812 | GEO

CDK11 phosphorylates SF3B1 and is essential for constitutive splicing (iCLIP)

2022-07-09 | GSE185811 | GEO

CDK11 phosphorylates SF3B1 and is essential for constitutive splicing (4sU-seq)

2022-07-09 | GSE185810 | GEO

CDK11 phosphorylates SF3B1 and is essential for constitutive splicing (RNA-seq)

2022-07-09 | GSE185809 | GEO