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Sharma KL, Jia S, Beacon TH, Adewumi I, López C, Hu P, Xu W, Davie JR. Mitogen-induced transcriptional programming in human fibroblasts. Gene 2021; 800:145842. [PMID: 34274479 DOI: 10.1016/j.gene.2021.145842] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 07/13/2021] [Indexed: 11/17/2022]
Abstract
Treatment of serum-starved quiescent human cells with fetal bovine serum (FBS), epidermal growth factor (EGF), or the phorbol ester (12-O-tetradecanoylphorbol-13-acetate, TPA) activates the RAS-MAPK pathway which initiates a transcriptional program which drives cells toward proliferation. Stimulation of the RAS-MAPK pathway activates mitogen- and stress-activated kinases (MSK) 1 and 2, which phosphorylate histone H3 at S10 (H3S10ph) or S28 (H3S28ph) (nucleosomal response) located at the regulatory regions of immediate-early genes, setting in motion a series of chromatin remodeling events that result in transcription initiation. To investigate immediate-early genes regulated by the MSK, we have completed transcriptome analyses (RNA sequencing) of human normal fibroblast cells (CCD-1070Sk) stimulated with EGF or TPA ± H89, a potent MSK/PKA inhibitor. The induction of many immediate-early genes was independent of MSK activity. However, the induction of immediate-early genes attenuated with H89 also had reduced induction with the PKA inhibitor, Rp-cAMPS. Several EGF-induced genes, coding for transcriptional repressors, were further upregulated with H89 but not with Rp-cAMPS, suggesting a role for MSK in modulating the induction level of these genes.
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Affiliation(s)
- Kiran L Sharma
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba R3E 0J9, Canada
| | - Shuo Jia
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba R3E 0J9, Canada
| | - Tasnim H Beacon
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba R3E 0J9, Canada; CancerCare Manitoba Research Institute, CancerCare Manitoba, Winnipeg, Manitoba R3E 0V9, Canada
| | - Ifeoluwa Adewumi
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba R3E 0J9, Canada
| | - Camila López
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba R3E 0J9, Canada
| | - Pingzhao Hu
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba R3E 0J9, Canada; CancerCare Manitoba Research Institute, CancerCare Manitoba, Winnipeg, Manitoba R3E 0V9, Canada
| | - Wayne Xu
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba R3E 0J9, Canada; CancerCare Manitoba Research Institute, CancerCare Manitoba, Winnipeg, Manitoba R3E 0V9, Canada
| | - James R Davie
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba R3E 0J9, Canada; CancerCare Manitoba Research Institute, CancerCare Manitoba, Winnipeg, Manitoba R3E 0V9, Canada.
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KSHV reactivation and novel implications of protein isomerization on lytic switch control. Viruses 2015; 7:72-109. [PMID: 25588053 PMCID: PMC4306829 DOI: 10.3390/v7010072] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 12/30/2014] [Indexed: 12/26/2022] Open
Abstract
In Kaposi’s sarcoma-associated herpesvirus (KSHV) oncogenesis, both latency and reactivation are hypothesized to potentiate tumor growth. The KSHV Rta protein is the lytic switch for reactivation. Rta transactivates essential genes via interactions with cofactors such as the cellular RBP-Jk and Oct-1 proteins, and the viral Mta protein. Given that robust viral reactivation would facilitate antiviral responses and culminate in host cell lysis, regulation of Rta’s expression and function is a major determinant of the latent-lytic balance and the fate of infected cells. Our lab recently showed that Rta transactivation requires the cellular peptidyl-prolyl cis/trans isomerase Pin1. Our data suggest that proline‑directed phosphorylation regulates Rta by licensing binding to Pin1. Despite Pin1’s ability to stimulate Rta transactivation, unchecked Pin1 activity inhibited virus production. Dysregulation of Pin1 is implicated in human cancers, and KSHV is the latest virus known to co-opt Pin1 function. We propose that Pin1 is a molecular timer that can regulate the balance between viral lytic gene expression and host cell lysis. Intriguing scenarios for Pin1’s underlying activities, and the potential broader significance for isomerization of Rta and reactivation, are highlighted.
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Zhang L, Zhang Y, Li X, Zhang L. Study on the synthesis and PKA-I binding activities of 5-alkynyl tubercidin analogues. Bioorg Med Chem 2002; 10:907-12. [PMID: 11836097 DOI: 10.1016/s0968-0896(01)00341-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
5-alkynyl tubercidin analogues were synthesized and their biological activities were evaluated. It was found that protein kinase A could be activated by 5-alkynyl tubercidin (9a) and cAMP-binding ability to PKA-I was selectively inhibited by it. Molecular modeling showed that the interaction of 9a and PKA-I was associated with the existence of hydrophobic alkynyl group. During the synthesis of tubercidin analogues, a pair of 2'-carbonyl participating abnormal coupling products (11a, 11b) was obtained, the structure was identified by X-ray crystalline diffraction.
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Affiliation(s)
- Liangren Zhang
- National Research Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 100083, Beijing, China
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