Optogenetic control of kinetochore function

Zhang, Huaiying; Aonbangkhen, Chanat; Tarasovetc, Ekaterina V.; Ballister, Edward R.; Chenoweth, David M.; Lampson, Michael A.

doi:10.1038/nchembio.2456

Cited by 72 publications

(89 citation statements)

References 45 publications

(59 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To test this hypothesis, we developed an optogenetic strategy to target active CDC42 to one pole of a centered spindle, which is normally symmetric, using a photocaged small molecule that heterodimerizes Halotag and E. coli DHFR (eDHFR) fusion proteins (27, 28) (Fig. 2C).…”

mentioning

confidence: 99%

Spindle asymmetry drives non-Mendelian chromosome segregation

Akera

Chmátal

Trimm

et al. 2017

Science

Self Cite

182

116

View full text Add to dashboard Cite

Genetic elements compete for transmission through meiosis, when haploid gametes are created from a diploid parent. Selfish elements can enhance their transmission through a process known as meiotic drive. In female meiosis, selfish elements drive by preferentially attaching to the egg side of the spindle. This implies some asymmetry between the two sides of the spindle, but molecular mechanisms underlying spindle asymmetry are unknown. Here we found that CDC42 signaling from the cell cortex regulated microtubule tyrosination to induce spindle asymmetry. NonMendelian segregation depended on this asymmetry. Cortical CDC42 depends on polarization directed by chromosomes, which are positioned near the cortex to allow the asymmetric cell division. Thus, selfish meiotic drivers exploit the asymmetry inherent in female meiosis to bias their transmission.Genetic conflict is inherent in any haploid-diploid life cycle because genetic elements compete for transmission through meiosis. Mendel's Law of Segregation states that alleles of a gene are transmitted with equal probability, but this law can be violated by selfish genetic elements through meiotic drive, for example by eliminating competing gametes (e.g., sperm killing or spore killing) or by exploiting the asymmetry in female meiosis to increase transmission to the egg. Despite the impact of meiotic drive on evolution and genetics (1-4), the underlying mechanisms are largely unknown. Female meiosis provides a clear opportunity for selfish elements to cheat because only chromosomes that segregate to the egg can be transmitted to offspring, while the rest are degraded in polar bodies. Conceptually, female meiotic drive depends on three conditions: asymmetry in cell fate, a functional difference between homologous chromosomes that influences their segregation, and asymmetry within the meiotic spindle (5). The asymmetry in cell fate is well established (6), and chromosomal rearrangements and amplifications of repetitive sequences (e.g., centromeres) are associated with biased segregation (7-10). Asymmetry within the meiotic spindle was noted in grasshopper in 1976 (11) but not studied further.Oocyte spindles are positioned close to the cortex and oriented perpendicular to the cortex so that cytokinesis produces a large egg and a small polar body. A selfish element drives by preferentially attaching to the egg side of the spindle, implying some difference in microtubules (MTs) between the egg and cortical sides. To determine how such spindle asymmetry is regulated, using mouse oocytes as a model for meiotic drive (10, 12), we tested for asymmetry in post-translational modifications that functionally diversify MTs ( To distinguish between these possibilities, we manipulated spindle position by treating oocytes with cytochalasin B (CCB) before maturation to inhibit actin polymerization. The nucleus drifted to the cortex in 24% of these oocytes, with the spindle positioned near the cortex by 3 h after germinal vesicle breakdown (GVBD) vs. migration at 6 h under norma...

show abstract

mentioning

confidence: 99%

Spindle asymmetry drives non-Mendelian chromosome segregation

Akera

Chmátal

Trimm

et al. 2017

Science

Self Cite

182

116

View full text Add to dashboard Cite

show abstract

mentioning

confidence: 99%

Spindle asymmetry drives non-Mendelian chromosome segregation

Akera

Chmátal

Trimm

et al. 2017

Preprint

Self Cite

View full text Add to dashboard Cite

Genetic elements compete for transmission through meiosis, when haploid gametes are created from a diploid parent. Selfish elements can enhance their transmission through meiotic drive, in violation of Mendel's Law of Segregation. In female meiosis, selfish elements drive by preferentially attaching to the egg side of the spindle, which implies some asymmetry between the two sides of the spindle, but molecular mechanisms underlying spindle asymmetry are unknown. Here we show that CDC42 signaling from the cell cortex regulates microtubule tyrosination to induce spindle asymmetry, and non-Mendelian segregation depends on this asymmetry. These signals depend on cortical polarization directed by chromosomes, which are positioned near the cortex to allow the asymmetric cell division. Thus, selfish meiotic drivers exploit the asymmetry inherent in female meiosis to bias their transmission.Genetic conflict is inherent in any haploid-diploid life cycle because genetic elements compete for transmission to the offspring through meiosis, the process by which haploids are generated. Mendel's Law of Segregation states that alleles of a gene are transmitted with equal probability, but it is increasingly clear that this law is often violated, and segregation can be manipulated by selfish genetic elements through meiotic drive. Drive can occur by eliminating competing gametes that do not contain the selfish element (e.g., sperm killing or spore killing) or by exploiting the asymmetry in female meiosis to increase the transmission of the selfish element to the egg. Although the impact of meiotic drive on many aspects of evolution and genetics is now recognized, with examples widespread across eukaryotes (1-4), the underlying mechanisms are largely unknown.Female meiosis provides a clear opportunity for selfish elements to cheat because of its inherent asymmetry: only chromosomes that segregate to the egg can be transmitted to offspring, while the rest are degraded in polar bodies. Conceptually, female meiotic drive depends on three conditions: asymmetry in cell fate, a functional not peer-reviewed) is the author/funder. All rights reserved. No reuse allowed without permission.The copyright holder for this preprint (which was . http://dx.doi.org/10.1101/180869 doi: bioRxiv preprint first posted online Aug. 25, 2017; 2 difference between homologous chromosomes that influences their segregation, and asymmetry within the meiotic spindle (5). The asymmetry in cell fate is well established (6), and chromosomal rearrangements and amplifications of repetitive sequences (e.g., centromeres) are associated with biased segregation (7-10). Asymmetry within the meiotic spindle was noted in grasshopper in 1976 (11), but not studied further, and molecular mechanisms regulating such asymmetry are unknown.Oocyte spindles are positioned close to the cortex and oriented perpendicular to the cortex in order to achieve the highly asymmetric cell division, so that cytokinesis produces a large egg and a small polar body (Fig. 1A). A selfish element ...

show abstract

“… (A) Dimerization schematic: SIM is fused to mCherry and eDHFR, and TRF1 is fused to Halo and GFP. The dimerizer is TNH: TMP(trimethoprim)-NVOC (6-nitroveratryl oxycarbonyl)-Halo (Zhang et al, 2017). (B-D) Cells expressing SIM-mCherry-DHFR (WT) or a SIM mutant that cannot interact with SUMO, together with Halo-GFP-TRF1, were incubated with TNH before fixing and staining for SUMO2/3.…”

Section: Resultsmentioning

confidence: 99%

“…The plasmids for inducing DNA damage at telomeres (mCherry-ER-DD-TRF1-FokI or Fok1 mutant) were previously published (Cho et al, 2014). For recruiting SIM to telomeres, TRF1 was substituted for SPC25 in the published 3xHalo-GFP-SPC25 plasmid (Zhang et al, 2017). SIM (or SIM mutant) for SIM-mCherry-eDHFR is from plasmids gifted by Michel Rosen (Banani et al, 2016b).…”

Section: Methodsmentioning

confidence: 99%

Liquid condensation drives telomere clustering during ALT

Liu

Dilley

Chenoweth

et al. 2019

Preprint

Self Cite

View full text Add to dashboard Cite

17Telomerase-free cancer cells employ a recombination-based alternative lengthening of 18 telomeres (ALT) pathway that depends on ALT-associated promyelocytic leukemia 19 (PML) nuclear bodies (APBs), whose function is unclear. We find that APBs behave as 20 liquid condensates, suggesting two potential mechanisms to promote telomere 21 elongation: condensation to enrich DNA repair factors for telomere synthesis and 22 coalescence to cluster telomeres to provide repair templates. Using chemically-induced 23 dimerization, we show that telomere sumoylation nucleates APB condensation via 24 SUMO-SIM (SUMO interaction motif) interactions and clusters telomeres. The induced 25 APBs lack DNA repair factors, indicating that these factors are clients recruited to the 26 APB scaffold rather than components that drive condensation. Telomere clustering, 27 however, relies only on liquid properties of the condensate, as an alternative 28 condensation chemistry also induces clustering. Our results demonstrate how the 29 material properties and chemical composition of APBs independently contribute to ALT, 30 suggesting a general framework for how liquid condensates promote cellular functions. 31 32 42 presence of APBs, a class of ALT telomere-associated promyelocytic leukemia (PML) 43 nuclear bodies used for ALT diagnosis (Yeager et al., 1999). PML nuclear bodies are 44 3 dynamic structures in the nucleus that transiently sequester up to 100 different proteins 45 that are implicated in many cellular functions including tumor suppression, DNA 46 replication, gene transcription, DNA repair, viral pathogenicity, cellular senescence and 47 apoptosis (Lallemand-Breitenbach and de The, 2010). While APBs are proposed to be 48 sites of telomere recombination during ALT, the precise functions of these specialized 49 PML nuclear bodies are poorly understood. Inhibiting APB formation by knocking down 50 PML protein, an essential component of PML nuclear bodies, leads to telomere 51shortening (Draskovic et al., 2009; Osterwald et al., 2015), indicating that APBs are 52 essential for ALT telomere maintenance. In addition to typical PML nuclear body 53 components, APBs contain proteins involved in homologous recombination such as 54 replication protein A (RPA), Rad51, and breast cancer susceptibility protein 1 (BRCA1) 55 (Nabetani and Ishikawa, 2011), which suggests that APBs promote telomere synthesis. 56Indeed, new telomere DNA synthesis has been detected in APBs (Cho et al., 2014; 57 Chung et al., 2011; O'sullivan et al., 2014; Sahin et al., 2014; Zhang et al., 2019). 58Telomeres also cluster within APBs, as another unique feature of ALT, presumably to 59 provide repair templates for telomere DNA synthesis. Many functionally distinct proteins 60 can initiate APB assembly, leading to the proposal of a multiple-pathway model (Chung 61 et al., 2011), as suggested by an RNA interference screen that identified close to thirty 62 proteins that affect APB formation, including proteins involved in telomere and 63 chromatin organizatio...

show abstract

Optogenetic control of kinetochore function

Cited by 72 publications

References 45 publications

Spindle asymmetry drives non-Mendelian chromosome segregation

Spindle asymmetry drives non-Mendelian chromosome segregation

Spindle asymmetry drives non-Mendelian chromosome segregation

Liquid condensation drives telomere clustering during ALT

Contact Info

Product

Resources

About