bims-micesi 2022-07-24 papers

bims-micesi

Biomed News

on Mitotic cell signalling

Issue of 2022–07–24
nine papers selected by
Valentina Piano, Max Planck Institute of Molecular Physiology

JAK2-CHK2 signaling safeguards the integrity of the mitotic spindle assembly checkpoint and genome stability.
The ciliopathy protein CCDC66 controls mitotic progression and cytokinesis by promoting microtubule nucleation and organization.
Time-keeping and decision-making in the cell cycle.
The CIP2A-TOPBP1 complex safeguards chromosomal stability during mitosis.
Phosphorylation of mixed lineage kinase MLK3 by cyclin-dependent kinases CDK1 and CDK2 controls ovarian cancer cell division.
Centriole growth is limited by the Cdk/Cyclin-dependent phosphorylation of Ana2/STIL.
Mitotic SENP3 activation couples with cGAS signaling in tumor cells to stimulate anti-tumor immunity.
The ubiquitin-ligase TRAF6 and TGFβ type I receptor form a complex with Aurora kinase B contributing to mitotic progression and cytokinesis in cancer cells.
Wnt signaling regulates hepatocyte cell division by a transcriptional repressor cascade.

Cell Death Dis. 2022 Jul 18. 13(7): 619

JAK2-CHK2 signaling safeguards the integrity of the mitotic spindle assembly checkpoint and genome stability.

Md Al Nayem Chowdhury, Shih-Wei Wang, Ching-Shu Suen, Ming-Jing Hwang, Yi-An Hsueh, Sheau-Yann Shieh.

Checkpoint kinase 2 (CHK2) plays an important role in safeguarding the mitotic progression, specifically the spindle assembly, though the mechanism of regulation remains poorly understood. Here, we identified a novel mitotic phosphorylation site on CHK2 Tyr156, and its responsible kinase JAK2. Expression of a phospho-deficient mutant CHK2 Y156F or treatment with JAK2 inhibitor IV compromised mitotic spindle assembly, leading to genome instability. In contrast, a phospho-mimicking mutant CHK2 Y156E restored mitotic normalcy in JAK2-inhibited cells. Mechanistically, we show that this phosphorylation is required for CHK2 interaction with and phosphorylation of the spindle assembly checkpoint (SAC) kinase Mps1, and failure of which results in impaired Mps1 kinetochore localization and defective SAC. Concordantly, analysis of clinical cancer datasets revealed that deletion of JAK2 is associated with increased genome alteration; and alteration in CHEK2 and JAK2 is linked to preferential deletion or amplification of cancer-related genes. Thus, our findings not only reveal a novel JAK2-CHK2 signaling axis that maintains genome integrity through SAC but also highlight the potential impact on genomic stability with clinical JAK2 inhibition.

DOI: https://doi.org/10.1038/s41419-022-05077-0
PLoS Biol. 2022 Jul 18. 20(7): e3001708

The ciliopathy protein CCDC66 controls mitotic progression and cytokinesis by promoting microtubule nucleation and organization.

Umut Batman, Jovana Deretic, Elif Nur Firat-Karalar.

Precise spatiotemporal control of microtubule nucleation and organization is critical for faithful segregation of cytoplasmic and genetic material during cell division and signaling via the primary cilium in quiescent cells. Microtubule-associated proteins (MAPs) govern assembly, maintenance, and remodeling of diverse microtubule arrays. While a set of conserved MAPs are only active during cell division, an emerging group of MAPs acts as dual regulators in dividing and nondividing cells. Here, we elucidated the nonciliary functions and molecular mechanism of action of the ciliopathy-linked protein CCDC66, which we previously characterized as a regulator of ciliogenesis in quiescent cells. We showed that CCDC66 dynamically localizes to the centrosomes, the bipolar spindle, the spindle midzone, the central spindle, and the midbody in dividing cells and interacts with the core machinery of centrosome maturation and MAPs involved in cell division. Loss-of-function experiments revealed its functions during mitotic progression and cytokinesis. Specifically, CCDC66 depletion resulted in defective spindle assembly and orientation, kinetochore fiber stability, chromosome alignment in metaphase as well as central spindle and midbody assembly and organization in anaphase and cytokinesis. Notably, CCDC66 regulates mitotic microtubule nucleation via noncentrosomal and centrosomal pathways via recruitment of gamma-tubulin to the centrosomes and the spindle. Additionally, CCDC66 bundles microtubules in vitro and in cells by its C-terminal microtubule-binding domain. Phenotypic rescue experiments showed that the microtubule and centrosome-associated pools of CCDC66 individually or cooperatively mediate its mitotic and cytokinetic functions. Collectively, our findings identify CCDC66 as a multifaceted regulator of the nucleation and organization of the diverse mitotic and cytokinetic microtubule arrays and provide new insight into nonciliary defects that underlie ciliopathies.

DOI: https://doi.org/10.1371/journal.pbio.3001708
Interface Focus. 2022 Aug 06. 12(4): 20210075

Time-keeping and decision-making in the cell cycle.

John J Tyson, Béla Novák.

  Cell growth, DNA replication, mitosis and division are the fundamental processes by which life is passed on from one generation of eukaryotic cells to the next. The eukaryotic cell cycle is intrinsically a periodic process but not so much a 'clock' as a 'copy machine', making new daughter cells as warranted. Cells growing under ideal conditions divide with clock-like regularity; however, if they are challenged with DNA-damaging agents or mitotic spindle disrupters, they will not progress to the next stage of the cycle until the damage is repaired. These 'decisions' (to exit and re-enter the cell cycle) are essential to maintain the integrity of the genome from generation to generation. A crucial challenge for molecular cell biologists in the 1990s was to unravel the genetic and biochemical mechanisms of cell cycle control in eukaryotes. Central to this effort were biochemical studies of the clock-like regulation of 'mitosis promoting factor' during synchronous mitotic cycles of fertilized frog eggs and genetic studies of the switch-like regulation of 'cyclin-dependent kinases' in yeast cells. In this review, we uncover some secrets of cell cycle regulation by mathematical modelling of increasingly more complex molecular regulatory networks of cell cycle 'clocks' and 'switches'.

Keywords:  bistable switches; cell cycle checkpoints; cell cycle regulation; cyclin-dependent kinases; limit cycles; mathematical models

DOI:  https://doi.org/10.1098/rsfs.2021.0075
Nat Commun. 2022 Jul 16. 13(1): 4143

The CIP2A-TOPBP1 complex safeguards chromosomal stability during mitosis.

Mara De Marco Zompit, Mònica Torres Esteban, Clémence Mooser, Salomé Adam, Silvia Emma Rossi, Alain Jeanrenaud, Pia-Amata Leimbacher, Daniel Fink, Ann-Marie K Shorrocks, Andrew N Blackford, Daniel Durocher, Manuel Stucki.

The accurate repair of DNA double-strand breaks (DSBs), highly toxic DNA lesions, is crucial for genome integrity and is tightly regulated during the cell cycle. In mitosis, cells inactivate DSB repair in favor of a tethering mechanism that stabilizes broken chromosomes until they are repaired in the subsequent cell cycle phases. How this is achieved mechanistically is not yet understood, but the adaptor protein TOPBP1 is critically implicated in this process. Here, we identify CIP2A as a TOPBP1-interacting protein that regulates TOPBP1 localization specifically in mitosis. Cells lacking CIP2A display increased radio-sensitivity, micronuclei formation and chromosomal instability. CIP2A is actively exported from the cell nucleus in interphase but, upon nuclear envelope breakdown at the onset of mitosis, gains access to chromatin where it forms a complex with MDC1 and TOPBP1 to promote TOPBP1 recruitment to sites of mitotic DSBs. Collectively, our data uncover CIP2A-TOPBP1 as a mitosis-specific genome maintenance complex.

DOI: https://doi.org/10.1038/s41467-022-31865-5
J Biol Chem. 2022 Jul 14. pii: S0021-9258(22)00705-0. [Epub ahead of print] 102263

Phosphorylation of mixed lineage kinase MLK3 by cyclin-dependent kinases CDK1 and CDK2 controls ovarian cancer cell division.

Luis Cedeno-Rosario, David Honda, Autumn M Sunderland, Mark D Lewandowski, William R Taylor, Deborah N Chadee.

  Mixed lineage kinase 3 (MLK3) is a serine/threonine MAP3K that promotes the activation of multiple mitogen-activated protein kinase pathways, and is required for invasion and proliferation of ovarian cancer cells. Inhibition of MLK activity causes G2/M arrest in HeLa cells; however, the regulation of MLK3 during ovarian cancer cell cycle progression is not known. Here, we found that MLK3 is phosphorylated in mitosis and that inhibition of cyclin-dependent kinase 1 (CDK1) prevented MLK3 phosphorylation. In addition, we observed that c-Jun N-terminal Kinase (JNK), a downstream target of MLK3 and a direct target of MKK4 (SEK1), was activated in G2 when CDK2 activity is increased and then inactivated at the beginning of mitosis concurrent with the increase in CDK1 and MLK3 phosphorylation. Using in vitro kinase assays and phospho-mutants, we determined that CDK1 phosphorylates MLK3 on Ser548 and decreases MLK3 activity during mitosis, while CDK2 phosphorylates MLK3 on Ser770 and increases MLK3 activity during G1/S and G2. We also found that MLK3 inhibition causes a reduction in cell proliferation and a cell cycle arrest in ovarian cancer cells, suggesting that MLK3 is required for ovarian cancer cell cycle progression. Taken together, our results suggest that phosphorylation of MLK3 by CDK1 and CDK2 is important for the regulation of MLK3 and JNK activities during G1/S, G2 and M in ovarian cancer cell division.

Keywords:  Mixed lineage kinase 3 (MLK3); c-Jun N-terminal kinase (JNK); cell division; cell proliferation; cell signaling; cyclin‐dependent kinase (CDK); ovarian cancer

DOI:  https://doi.org/10.1016/j.jbc.2022.102263
J Cell Biol. 2022 Sep 05. pii: e202205058. [Epub ahead of print]221(9):

Centriole growth is limited by the Cdk/Cyclin-dependent phosphorylation of Ana2/STIL.

Thomas L Steinacker, Siu-Shing Wong, Zsofia A Novak, Saroj Saurya, Lisa Gartenmann, Eline J H van Houtum, Judith R Sayers, B Christoffer Lagerholm, Jordan W Raff.

Centrioles duplicate once per cell cycle, but it is unclear how daughter centrioles assemble at the right time and place and grow to the right size. Here, we show that in Drosophila embryos the cytoplasmic concentrations of the key centriole assembly proteins Asl, Plk4, Ana2, Sas-6, and Sas-4 are low, but remain constant throughout the assembly process-indicating that none of them are limiting for centriole assembly. The cytoplasmic diffusion rate of Ana2/STIL, however, increased significantly toward the end of S-phase as Cdk/Cyclin activity in the embryo increased. A mutant form of Ana2 that cannot be phosphorylated by Cdk/Cyclins did not exhibit this diffusion change and allowed daughter centrioles to grow for an extended period. Thus, the Cdk/Cyclin-dependent phosphorylation of Ana2 seems to reduce the efficiency of daughter centriole assembly toward the end of S-phase. This helps to ensure that daughter centrioles stop growing at the correct time, and presumably also helps to explain why centrioles cannot duplicate during mitosis.

DOI: https://doi.org/10.1083/jcb.202205058
Cell Death Dis. 2022 Jul 22. 13(7): 640

Mitotic SENP3 activation couples with cGAS signaling in tumor cells to stimulate anti-tumor immunity.

Gaolei Hu, Yalan Chen, Xinyu Yang, Yang Wang, Jianli He, Tianshi Wang, Qiuju Fan, Liufu Deng, Jun Tu, Hongsheng Tan, Jinke Cheng.

Our previous studies show that the mitotic phosphorylation of SUMO-specific protease 3 (SENP3) can inhibit its de-SUMOylation activity in G2/M phase of the cell cycle. Inhibition of SENP3 plays a critical role in the correct separation of sister chromatids in mitosis. The mutation of mitotic SENP3 phosphorylation causes chromosome instability and promotes tumorigenesis. In this study, we find that the mutation of mitotic SENP3 phosphorylation in tumor cells can suppress tumor growth in immune-competent mouse model. We further detect an increase of CD8+ T cell infiltration in the tumors, which is essential for the anti-tumor effect in immune-competent mouse model. Moreover, we find that mitotic SENP3 activation increases micronuclei formation, which can activate cGAS signaling-dependent innate immune response. We confirmed that cGAS signaling mediates the mitotic SENP3 activation-induced anti-tumor immunity. We further show that p53 responding to DNA damage activates mitotic SENP3 by inhibiting phosphorylation, and further increases cellular senescence as well as the related innate immune response in tumor cells. Furthermore, TCGA database demonstrates that the SENP3 expression positively correlates with the induction of innate immune response as well as the survival of the p53 mutant pancreatic cancer patients. Together, these data reveal that mitotic SENP3 activation in tumor cells can promote host anti-tumor immune response by coupling with cGAS signaling.

DOI: https://doi.org/10.1038/s41419-022-05063-6
EBioMedicine. 2022 Jul 09. pii: S2352-3964(22)00336-X. [Epub ahead of print] 104155

The ubiquitin-ligase TRAF6 and TGFβ type I receptor form a complex with Aurora kinase B contributing to mitotic progression and cytokinesis in cancer cells.

Jie Song, Yang Zhou, Ihor Yakymovych, Alexej Schmidt, Chunyan Li, Carl-Henrik Heldin, Maréne Landström.

   BACKGROUND: Transforming growth factor β (TGFβ) is overexpressed in several advanced cancer types and promotes tumor progression. We have reported that the intracellular domain (ICD) of TGFβ receptor (TβR) I is cleaved by proteolytic enzymes in cancer cells, and then translocated to the nucleus in a manner dependent on the endosomal adaptor proteins APPL1/2, driving an invasiveness program. How cancer cells evade TGFβ-induced growth inhibition is unclear.
METHODS: We performed microarray analysis to search for genes regulated by APPL1/2 proteins in castration-resistant prostate cancer (CRPC) cells. We investigated the role of TβRI and TRAF6 in mitosis in cancer cell lines cultured in 10% FBS in the absence of exogenous TGFβ. The molecular mechanism of the ubiquitination of AURKB by TRAF6 in mitosis and the formation of AURKB-TβRI complex in cancer cell lines and tissue microarrays was also studied.
FINDINGS: During mitosis and cytokinesis, AURKB-TβRI complexes formed in midbodies in CRPC and KELLY neuroblastoma cells. TRAF6 induced polyubiquitination of AURKB on K85 and K87, protruding on the surface of AURKB to facilitate its activation. AURKB-TβRI complexes in patient's tumor tissue sections correlated with the malignancy of prostate cancer.
INTERPRETATION: The AURKB-TβRI complex may become a prognostic biomarker for patients with risk of developing aggressive PC.
FUNDING: Swedish Medical Research Council (2019-01598, ML; 2015-02757 and 2020-01291, CHH), the Swedish Cancer Society (20 0964, ML), a regional agreement between Umeå University and Region Västerbotten (ALF; RV-939377, -967041, -970057, ML). The European Research Council (787472, CHH). KAW 2019.0345, and the Kempe Foundation SMK-1866; ML. National Microscopy Infrastructure (NMI VR-RFI 2016-00968).

Keywords:  APPL1; AURKB; Cancer; Mitosis; TRAF6; TβRI

DOI:  https://doi.org/10.1016/j.ebiom.2022.104155
Proc Natl Acad Sci U S A. 2022 Jul 26. 119(30): e2203849119

Wnt signaling regulates hepatocyte cell division by a transcriptional repressor cascade.

Yinhua Jin, Teni Anbarchian, Peng Wu, Abby Sarkar, Matt Fish, Weng Chuan Peng, Roel Nusse.

  Cell proliferation is tightly controlled by inhibitors that block cell cycle progression until growth signals relieve this inhibition, allowing cells to divide. In several tissues, including the liver, cell proliferation is inhibited at mitosis by the transcriptional repressors E2F7 and E2F8, leading to formation of polyploid cells. Whether growth factors promote mitosis and cell cycle progression by relieving the E2F7/E2F8-mediated inhibition is unknown. We report here on a mechanism of cell division control in the postnatal liver, in which Wnt/β-catenin signaling maintains active hepatocyte cell division through Tbx3, a Wnt target gene. The TBX3 protein directly represses transcription of E2f7 and E2f8, thereby promoting mitosis. This cascade of sequential transcriptional repressors, initiated by Wnt signals, provides a paradigm for exploring how commonly active developmental signals impact cell cycle completion.

Keywords:  Wnt; liver; proliferation

DOI:  https://doi.org/10.1073/pnas.2203849119