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Hunter O, Talkish J, Quick-Cleveland J, Igel H, Tan A, Kuersten S, Katzman S, Donohue JP, S Jurica M, Ares M. Broad variation in response of individual introns to splicing inhibitors in a humanized yeast strain. RNA (NEW YORK, N.Y.) 2024; 30:149-170. [PMID: 38071476 PMCID: PMC10798247 DOI: 10.1261/rna.079866.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 11/14/2023] [Indexed: 12/19/2023]
Abstract
Intron branchpoint (BP) recognition by the U2 snRNP is a critical step of splicing, vulnerable to recurrent cancer mutations and bacterial natural product inhibitors. The BP binds a conserved pocket in the SF3B1 (human) or Hsh155 (yeast) U2 snRNP protein. Amino acids that line this pocket affect the binding of splicing inhibitors like Pladienolide-B (Plad-B), such that organisms differ in their sensitivity. To study the mechanism of splicing inhibitor action in a simplified system, we modified the naturally Plad-B resistant yeast Saccharomyces cerevisiae by changing 14 amino acids in the Hsh155 BP pocket to those from human. This humanized yeast grows normally, and splicing is largely unaffected by the mutation. Splicing is inhibited within minutes after the addition of Plad-B, and different introns appear inhibited to different extents. Intron-specific inhibition differences are also observed during cotranscriptional splicing in Plad-B using single-molecule intron tracking to minimize gene-specific transcription and decay rates that cloud estimates of inhibition by standard RNA-seq. Comparison of Plad-B intron sensitivities to those of the structurally distinct inhibitor Thailanstatin-A reveals intron-specific differences in sensitivity to different compounds. This work exposes a complex relationship between the binding of different members of this class of inhibitors to the spliceosome and intron-specific rates of BP recognition and catalysis. Introns with variant BP sequences seem particularly sensitive, echoing observations from mammalian cells, where monitoring individual introns is complicated by multi-intron gene architecture and alternative splicing. The compact yeast system may hasten the characterization of splicing inhibitors, accelerating improvements in selectivity and therapeutic efficacy.
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Affiliation(s)
- Oarteze Hunter
- Center for Molecular Biology of RNA, University of California, Santa Cruz, California 95064, USA
| | - Jason Talkish
- Center for Molecular Biology of RNA, University of California, Santa Cruz, California 95064, USA
| | - Jen Quick-Cleveland
- Center for Molecular Biology of RNA, University of California, Santa Cruz, California 95064, USA
| | - Haller Igel
- Center for Molecular Biology of RNA, University of California, Santa Cruz, California 95064, USA
| | - Asako Tan
- Illumina, Inc., Madison, Wisconsin 53719, USA
| | | | - Sol Katzman
- Center for Molecular Biology of RNA, University of California, Santa Cruz, California 95064, USA
| | - John Paul Donohue
- Center for Molecular Biology of RNA, University of California, Santa Cruz, California 95064, USA
| | - Melissa S Jurica
- Center for Molecular Biology of RNA, University of California, Santa Cruz, California 95064, USA
| | - Manuel Ares
- Center for Molecular Biology of RNA, University of California, Santa Cruz, California 95064, USA
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Hunter O, Talkish J, Quick-Cleveland J, Igel H, Tan A, Kuersten S, Katzman S, Donohue JP, Jurica M, Ares M. Broad variation in response of individual introns to splicing inhibitors in a humanized yeast strain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.05.560965. [PMID: 37873484 PMCID: PMC10592967 DOI: 10.1101/2023.10.05.560965] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Intron branch point (BP) recognition by the U2 snRNP is a critical step of splicing, vulnerable to recurrent cancer mutations and bacterial natural product inhibitors. The BP binds a conserved pocket in the SF3B1 (human) or Hsh155 (yeast) U2 snRNP protein. Amino acids that line this pocket affect binding of splicing inhibitors like Pladienolide-B (Plad-B), such that organisms differ in their sensitivity. To study the mechanism of splicing inhibitor action in a simplified system, we modified the naturally Plad-B resistant yeast Saccharomyces cerevisiae by changing 14 amino acids in the Hsh155 BP pocket to those from human. This humanized yeast grows normally, and splicing is largely unaffected by the mutation. Splicing is inhibited within minutes after addition of Plad-B, and different introns appear inhibited to different extents. Intron-specific inhibition differences are also observed during co-transcriptional splicing in Plad-B using single-molecule intron tracking (SMIT) to minimize gene-specific transcription and decay rates that cloud estimates of inhibition by standard RNA-seq. Comparison of Plad-B intron sensitivities to those of the structurally distinct inhibitor Thailanstatin-A reveals intron-specific differences in sensitivity to different compounds. This work exposes a complex relationship between binding of different members of this class of inhibitors to the spliceosome and intron-specific rates of BP recognition and catalysis. Introns with variant BP sequences seem particularly sensitive, echoing observations from mammalian cells, where monitoring individual introns is complicated by multi-intron gene architecture and alternative splicing. The compact yeast system may hasten characterization of splicing inhibitors, accelerating improvements in selectivity and therapeutic efficacy.
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Affiliation(s)
- Oarteze Hunter
- Center for Molecular Biology of RNA, University of California, Santa Cruz, CA 95064
| | - Jason Talkish
- Center for Molecular Biology of RNA, University of California, Santa Cruz, CA 95064
| | - Jen Quick-Cleveland
- Center for Molecular Biology of RNA, University of California, Santa Cruz, CA 95064
| | - Haller Igel
- Center for Molecular Biology of RNA, University of California, Santa Cruz, CA 95064
| | | | | | - Sol Katzman
- Center for Molecular Biology of RNA, University of California, Santa Cruz, CA 95064
| | - John Paul Donohue
- Center for Molecular Biology of RNA, University of California, Santa Cruz, CA 95064
| | - Melissa Jurica
- Center for Molecular Biology of RNA, University of California, Santa Cruz, CA 95064
| | - Manuel Ares
- Center for Molecular Biology of RNA, University of California, Santa Cruz, CA 95064
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Farina AR, Cappabianca L, Sebastiano M, Zelli V, Guadagni S, Mackay AR. Hypoxia-induced alternative splicing: the 11th Hallmark of Cancer. J Exp Clin Cancer Res 2020; 39:110. [PMID: 32536347 PMCID: PMC7294618 DOI: 10.1186/s13046-020-01616-9] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 06/03/2020] [Indexed: 12/16/2022] Open
Abstract
Hypoxia-induced alternative splicing is a potent driving force in tumour pathogenesis and progression. In this review, we update currents concepts of hypoxia-induced alternative splicing and how it influences tumour biology. Following brief descriptions of tumour-associated hypoxia and the pre-mRNA splicing process, we review the many ways hypoxia regulates alternative splicing and how hypoxia-induced alternative splicing impacts each individual hallmark of cancer. Hypoxia-induced alternative splicing integrates chemical and cellular tumour microenvironments, underpins continuous adaptation of the tumour cellular microenvironment responsible for metastatic progression and plays clear roles in oncogene activation and autonomous tumour growth, tumor suppressor inactivation, tumour cell immortalization, angiogenesis, tumour cell evasion of programmed cell death and the anti-tumour immune response, a tumour-promoting inflammatory response, adaptive metabolic re-programming, epithelial to mesenchymal transition, invasion and genetic instability, all of which combine to promote metastatic disease. The impressive number of hypoxia-induced alternative spliced protein isoforms that characterize tumour progression, classifies hypoxia-induced alternative splicing as the 11th hallmark of cancer, and offers a fertile source of potential diagnostic/prognostic markers and therapeutic targets.
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Affiliation(s)
- Antonietta Rosella Farina
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Lucia Cappabianca
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Michela Sebastiano
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Veronica Zelli
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Stefano Guadagni
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Andrew Reay Mackay
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy
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Ma LF, Chen MJ, Liang DE, Shi LM, Ying YM, Shan WG, Li GQ, Zhan ZJ. Streptomyces albogriseolus SY67903 Produces Eunicellin Diterpenoids Structurally Similar to Terpenes of the Gorgonian Muricella sibogae, the Bacterial Source. JOURNAL OF NATURAL PRODUCTS 2020; 83:1641-1645. [PMID: 32367724 DOI: 10.1021/acs.jnatprod.0c00147] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Microeunicellols A (1) and B (2), two undescribed eunicellin diterpenoids, were isolated from the culture of a bacterial symbiont, Streptomyces albogriseolus SY67903. Their structures, including absolute configurations revealed by spectroscopic data and single-crystal X-ray diffraction analysis, are closely related with the diterpenoids from its host, a South China Sea gorgonian, Muricella sibogae. This is the first report of eunicellin diterpenoids, commonly coral-derived, from a bacterial symbiont of coral. The chemical metabolic relationship between the bacterium and its host is discussed. Biological evaluation revealed that compound 1 possessed cytotoxicities against several human cancer cell lines.
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Affiliation(s)
- Lie-Feng Ma
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
- Zhejiang Xinguang Pharmaceutical Limited Liability Company, Shaoxing 312400, People's Republic of China
| | - Meng-Jia Chen
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Dong-E Liang
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Lin-Mei Shi
- Lishui Technology College, Lishui 323000, People's Republic of China
| | - You-Min Ying
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Wei-Guang Shan
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Guo-Qiang Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, People's Republic of China
| | - Zha-Jun Zhan
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
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