1
|
Jin N, Jin Y, Oikawa Y, Nakano A, Ohsumi Y, Weisman LS. A non-canonical CDK, Pho85 regulates the restart of the cell-cycle following stress. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.27.609989. [PMID: 39253458 PMCID: PMC11383280 DOI: 10.1101/2024.08.27.609989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/11/2024]
Abstract
Environmental stress induces an arrest of the cell cycle. Thus, release from this arrest is essential for cell survival. The cell-cycle-arrest occurs via the down regulation of the cyclins that drive the main cyclin dependent kinase, CDK1/Cdc28. However, it was not clear how cells escape this potentially fatal arrest. Here we show that prior to the restoration of CDK1/Cdc28 cyclins, a non-canonical CDK, Pho85, initiates a cascade to restart the cell cycle. We demonstrate that following stress, Pho85 phosphorylates the Sch9 kinase, which in turn directly phosphorylates the transcriptional inhibitor Whi5, the yeast analog of RB1/retinoblastoma, and a CDK1 target. This promotes Whi5 translocation from the nucleus, and the release of the stress-induced arrest at G 1 phase. In addition, we find that in parallel with Pho85, CDK1/Cdc28 also plays a role in the control of Whi5. Together, these findings provide insights into how cells re-enter the cell cycle during recovery from stress and reveal that a non-canonical CDK and cyclin takes on essential roles and acts via a pathway that functions in parallel with CDK1/Cdc28.
Collapse
|
2
|
The Critical Role of 12-Methyl Group of Anthracycline Dutomycin to Its Antiproliferative Activity. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27103348. [PMID: 35630823 PMCID: PMC9144609 DOI: 10.3390/molecules27103348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/19/2022] [Accepted: 05/20/2022] [Indexed: 11/26/2022]
Abstract
Anthracycline dutomycin is a tetracyclic quinone glycoside produced by Streptomyces minoensis NRRL B-5482. SW91 is a C-12 demethylated dutomycin derivative, which was identified in our previous research. In vitro cytotoxicity and apoptosis assays of these two compounds were conducted to demonstrate their antiproliferation activities. The results showed that both dutomycin and SW91 block cells at the S phase, whereas dutomycin shows more significant inhibition of cell growth. Their interactions with calf thymus DNA (CT-DNA) were investigated, with dutomycin exhibiting higher binding affinity. The molecular docking demonstrated that the 12-methyl group makes dutomycin attach to the groove of DNA. These findings suggest that dutomycin has binding higher affinity to DNA and impairs DNA replication resulting in more significant antitumor activity.
Collapse
|
3
|
Carballar R, Martínez-Láinez JM, Samper B, Bru S, Bállega E, Mirallas O, Ricco N, Clotet J, Jiménez J. CDK-mediated Yku80 Phosphorylation Regulates the Balance Between Non-homologous End Joining (NHEJ) and Homologous Directed Recombination (HDR). J Mol Biol 2020; 432:166715. [PMID: 33217428 DOI: 10.1016/j.jmb.2020.11.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 11/04/2020] [Accepted: 11/11/2020] [Indexed: 11/28/2022]
Abstract
There are two major pathways for repairing DNA double-strand breaks (DSBs): homologous directed recombination (HDR) and non-homologous end-joining (NHEJ). While NHEJ functions throughout the cell cycle, HDR is only possible during S/G2 phases, suggesting that there are cell cycle-specific mechanisms regulating the balance between the two repair systems. The regulation exerted by CDKs on HDR has been extensively demonstrated, and here we present evidence that the CDK Pho85, in association with the G1 cyclin Pcl1, phosphorylates Yku80 on Ser 623 to regulate NHEJ activity. Cells bearing a non-phosphorylatable version of Yku80 show increased NHEJ and reduced HDR activity. Accordingly, yku80S623A cells present diminished viability upon treatment with the DSB-producer bleomycin, specifically in the G2 phase of the cell cycle. Interestingly, the mutation of the equivalent residue in human Ku80 increases sensitivity to bleomycin in several cancer cell lines, suggesting that this mechanism is conserved in humans. Altogether, our results reveal a new mechanism whereby G1-CDKs mediate the choice between HDR and NHEJ repair pathways, putting the error prone NHEJ on a leash and enabling error free HDR in G2 when homologous sequences are available.
Collapse
Affiliation(s)
- Reyes Carballar
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Joan M Martínez-Láinez
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Bàrbara Samper
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Samuel Bru
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Elisabet Bállega
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Oriol Mirallas
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Natalia Ricco
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Josep Clotet
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain.
| | - Javier Jiménez
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain.
| |
Collapse
|
4
|
Li N, Guo W, Li Y, Zuo H, Zhang H, Wang Z, Zhao Y, Yang F, Ren G, Zhang S. Construction and anti-tumor activities of disulfide-linked docetaxel-dihydroartemisinin nanoconjugates. Colloids Surf B Biointerfaces 2020; 191:111018. [PMID: 32304917 DOI: 10.1016/j.colsurfb.2020.111018] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/02/2020] [Accepted: 04/04/2020] [Indexed: 12/19/2022]
Abstract
Co-delivery of anti-tumor agents with outstanding stimulus-triggered drug release in tumor cells, especially with the aid of nanotechnology, provided the possibility to enhance delivery efficiency for targeting tumor cells and antitumor efficacy. In this paper, docetaxel-dihydroartemisinin nanoconjugates linked by disulfide bond were designed to increase co-delivery and anti-tumor efficacy. Docetaxel and dihydroartemisinin were synthesized using two-step reaction and furtherly assembled to nanoconjugates. Nanoprescription was optimized to evaluate its physicochemical properties. In vitro anti-tumor activities of nanoformulation were assessed by MTT. The flow cytometry was adopted to analyze cell apoptosis and cell cycle arrest. The wound healing assay was used to evaluate antimigratory-property. In vivo pharmacokinetic and pharmacodynamic studies were investigated in rats and 4T1 bearing Balb/c mice model after intravenous injection, respectively. The chemical structure of conjugate was confirmed. The prepared nanoparticles possessed uniform size distribution (172.10 ± 1.70 nm, PDI 0.05 ± 0.01), was stable during storage period, sustained release profiles and sensitive reduction responsiveness. MTT assay indicated that the toxicity of nanoconjugates was slightly weak. Flow cytometry studies showed that nanoconjugates could promote early apoptosis significantly and mainly arose from G0/G1 phase. The wound healing assay provided an obvious antimetastatic potential of nanoparticles in 4T1 cells. The result of pharmacokinetic study suggested that nanoconjugates exhibited higher exposure levels. In vivo pharmacodynamic research showed that mice treated with docetaxel-dihydroartemisinin nanoconjugates had lower systemic toxicity and higher survival ratio than those of control groups. This potential of nanoconjugates was developed as a novel nanoplateform to treat tumor.
Collapse
Affiliation(s)
- Ning Li
- School of Pharmacy, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Wenju Guo
- School of Pharmacy, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Yujie Li
- School of Pharmacy, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Hengtong Zuo
- School of Pharmacy, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Huihui Zhang
- School of Pharmacy, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Zhaoyun Wang
- School of Pharmacy, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Yongdan Zhao
- School of Pharmacy, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Fan Yang
- School of Pharmacy, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Guolian Ren
- School of Pharmacy, Shanxi Medical University, Taiyuan, Shanxi, China.
| | - Shuqiu Zhang
- School of Pharmacy, Shanxi Medical University, Taiyuan, Shanxi, China.
| |
Collapse
|
5
|
Protein Phosphatases in G1 Regulation. Int J Mol Sci 2020; 21:ijms21020395. [PMID: 31936296 PMCID: PMC7013402 DOI: 10.3390/ijms21020395] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/29/2019] [Accepted: 12/31/2019] [Indexed: 01/15/2023] Open
Abstract
Eukaryotic cells make the decision to proliferate, to differentiate or to cease dividing during G1, before passage through the restriction point or Start. Keeping cyclin-dependent kinase (CDK) activity low during this period restricts commitment to a new cell cycle and is essential to provide the adequate timeframe for the sensing of environmental signals. Here, we review the role of protein phosphatases in the modulation of CDK activity and as the counteracting force for CDK-dependent substrate phosphorylation, in budding and fission yeast. Moreover, we discuss recent findings that place protein phosphatases in the interface between nutritional signalling pathways and the cell cycle machinery.
Collapse
|