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Henfrey C, Murphy S, Tellier M. Regulation of mature mRNA levels by RNA processing efficiency. NAR Genom Bioinform 2023; 5:lqad059. [PMID: 37305169 PMCID: PMC10251645 DOI: 10.1093/nargab/lqad059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 05/13/2023] [Accepted: 05/24/2023] [Indexed: 06/13/2023] Open
Abstract
Transcription and co-transcriptional processes, including pre-mRNA splicing and mRNA cleavage and polyadenylation, regulate the production of mature mRNAs. The carboxyl terminal domain (CTD) of RNA polymerase (pol) II, which comprises 52 repeats of the Tyr1Ser2Pro3Thr4Ser5Pro6Ser7 peptide, is involved in the coordination of transcription with co-transcriptional processes. The pol II CTD is dynamically modified by protein phosphorylation, which regulates recruitment of transcription and co-transcriptional factors. We have investigated whether mature mRNA levels from intron-containing protein-coding genes are related to pol II CTD phosphorylation, RNA stability, and pre-mRNA splicing and mRNA cleavage and polyadenylation efficiency. We find that genes that produce a low level of mature mRNAs are associated with relatively high phosphorylation of the pol II CTD Thr4 residue, poor RNA processing, increased chromatin association of transcripts, and shorter RNA half-life. While these poorly-processed transcripts are degraded by the nuclear RNA exosome, our results indicate that in addition to RNA half-life, chromatin association due to a low RNA processing efficiency also plays an important role in the regulation of mature mRNA levels.
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Affiliation(s)
- Callum Henfrey
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Shona Murphy
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Michael Tellier
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
- Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, UK
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Phosphorylation of the Human DNA Glycosylase NEIL2 Is Affected by Oxidative Stress and Modulates Its Activity. Antioxidants (Basel) 2023; 12:antiox12020355. [PMID: 36829914 PMCID: PMC9952225 DOI: 10.3390/antiox12020355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 01/25/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023] Open
Abstract
The DNA glycosylase NEIL2 plays a central role in maintaining genome integrity, in particular during oxidative stress, by recognizing oxidized base lesions and initiating repair of these via the base excision repair (BER) pathway. Post-translational modifications are important molecular switches that regulate and coordinate the BER pathway, and thereby enable a rapid and fine-tuned response to DNA damage. Here, we report for the first time that human NEIL2 is regulated by phosphorylation. We demonstrate that NEIL2 is phosphorylated by the two kinases cyclin-dependent kinase 5 (CDK5) and protein kinase C (PKC) in vitro and in human SH-SY5Y neuroblastoma cells. The phosphorylation of NEIL2 by PKC causes a substantial reduction in NEIL2 repair activity, while CDK5 does not directly alter the enzymatic activity of NEIL2 in vitro, suggesting distinct modes of regulating NEIL2 function by the two kinases. Interestingly, we show a rapid dephosphorylation of NEIL2 in response to oxidative stress in SH-SY5Y cells. This points to phosphorylation as an important modulator of NEIL2 function in this cellular model, not least during oxidative stress.
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Trembley JH, Kren BT, Afzal M, Scaria GA, Klein MA, Ahmed K. Protein kinase CK2 – diverse roles in cancer cell biology and therapeutic promise. Mol Cell Biochem 2022; 478:899-926. [PMID: 36114992 PMCID: PMC9483426 DOI: 10.1007/s11010-022-04558-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 09/01/2022] [Indexed: 11/29/2022]
Abstract
The association of protein kinase CK2 (formerly casein kinase II or 2) with cell growth and proliferation in cells was apparent at early stages of its investigation. A cancer-specific role for CK2 remained unclear until it was determined that CK2 was also a potent suppressor of cell death (apoptosis); the latter characteristic differentiated its function in normal versus malignant cells because dysregulation of both cell growth and cell death is a universal feature of cancer cells. Over time, it became evident that CK2 exerts its influence on a diverse range of cell functions in normal as well as in transformed cells. As such, CK2 and its substrates are localized in various compartments of the cell. The dysregulation of CK2 is documented in a wide range of malignancies; notably, by increased CK2 protein and activity levels with relatively moderate change in its RNA abundance. High levels of CK2 are associated with poor prognosis in multiple cancer types, and CK2 is a target for active research and testing for cancer therapy. Aspects of CK2 cellular roles and targeting in cancer are discussed in the present review, with focus on nuclear and mitochondrial functions and prostate, breast and head and neck malignancies.
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Affiliation(s)
- Janeen H Trembley
- Research Service, Minneapolis VA Health Care System, Minneapolis, MN, 55417, USA.
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, 55455, USA.
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, 55455, USA.
| | - Betsy T Kren
- Research Service, Minneapolis VA Health Care System, Minneapolis, MN, 55417, USA
| | - Muhammad Afzal
- Department of Biochemistry, Riphah International University, Islamabad, Pakistan
| | - George A Scaria
- Hematology/Oncology Section, Primary Care Service Line, Minneapolis VA Health Care System, Minneapolis, MN, 55417, USA
| | - Mark A Klein
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, 55455, USA
- Hematology/Oncology Section, Primary Care Service Line, Minneapolis VA Health Care System, Minneapolis, MN, 55417, USA
- Department of Medicine, Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Khalil Ahmed
- Research Service, Minneapolis VA Health Care System, Minneapolis, MN, 55417, USA.
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, 55455, USA.
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, 55455, USA.
- Department of Urology, University of Minnesota, Minneapolis, MN, 55455, USA.
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