<i>Naumovozyma castellii</i>: an alternative model for budding yeast molecular biology

Cohn, Marita; Andersson, Ahu Karademir

doi:10.1002/yea.3218

Cited by 12 publications

(14 citation statements)

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“…The budding yeast Naumovozyma castellii (also known as S. castellii ), which belongs to the family of Saccharomycetaceae, has been extensively used for studies in comparative genomics and molecular evolution. Its amenability for genetic modification has rendered it a feasible model organism for molecular genetic functional analyses and it has significantly contributed with discoveries of fundamental molecular mechanisms in the fields of centromeres, mitochondria, RNAi and telomeres 37 . The telomeres of N. castellii share many features with those of human cells.…”

Section: Introductionmentioning

confidence: 99%

Rap1 and Cdc13 have complementary roles in preventing exonucleolytic degradation of telomere 5′ ends

Runnberg

Narayanan

Cohn

2017

Sci Rep

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Telomere DNA ends with a single-stranded 3′ overhang. Long 3′ overhangs may cause aberrant DNA damage responses and accelerate telomere attrition, which is associated with cancer and aging, respectively. Genetic studies have indicated several important players in preventing 5′ end hyper-resection, yet detailed knowledge about the molecular mechanism in which they act is still lacking. Here, we use an in vitro DNA 5′ end protection assay, to study how N. castellii Cdc13 and Rap1 protect against 5′ exonucleolytic degradation by λ-exonuclease. The homogeneous telomeric repeat sequence of N. castellii allows us to study their protection ability at exact binding sites relative to the 5′ end. We find efficient protection by both Cdc13 and Rap1 when bound close to the 5′ end. Notably, Rap1 provides protection when binding dsDNA at a distance from the 5′ end. The DNA binding domain of Rap1 is sufficient for 5′ end protection, and its wrapping loop region is essential. Intriguingly, Rap1 facilitates protection also when its binding site contains 2 nt of ssDNA, thus spanning across the ds-ss junction. These results highlight a role of Rap1 in 5′ end protection and indicate that Cdc13 and Rap1 have complementary roles in maintaining proper 3′ overhang length.

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Section: Introductionmentioning

confidence: 99%

Rap1 and Cdc13 have complementary roles in preventing exonucleolytic degradation of telomere 5′ ends

Runnberg

Narayanan

Cohn

2017

Sci Rep

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“…As positive controls for linear chromosomes, we analyzed karyotypes of the parental strain and two isogenic WT strains obtained from the same tetrad, which all showed eight chromosomal bands in the PFGE (Figure 5A, lanes 1 and 3-4). As N. castellii was previously shown to have 10 chromosomes in the whole genome sequencing approach, probably some of the chromosomes are not resolving on the PFGE gel (Cliften et al 2006; Gordon et al 2011; Karademir Andersson and Cohn 2017). This notion is supported by the variation in signal intensity of the bands, suggesting that some bands include overlapping chromosomes.…”

Section: Resultsmentioning

confidence: 99%

“…The budding yeast Naumovozyma castellii has been used as a model organism in telomere studies owing to its human-like telomere structure and maintenance (Karademir Andersson and Cohn 2017). N. castellii belongs to an evolutionary lineage that underwent whole genome duplication followed by a massive gene loss (Cliften et al 2006; Karademir Andersson et al 2017).…”

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confidence: 99%

“…N. castellii belongs to an evolutionary lineage that underwent whole genome duplication followed by a massive gene loss (Cliften et al 2006; Karademir Andersson et al 2017). Its genome is sequenced and has been used extensively in comparative genomics (Karademir Andersson and Cohn 2017). N. castellii has ten chromosomes and a genome size of 11.2 Mb (Cliften et al 2006; Gordon et al 2011).…”

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Alternative Lengthening of Telomeres in the Budding Yeast Naumovozyma castellii

Cohn

Andersson

Mateo

et al. 2019

G3 Genes|Genomes|Genetics

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The enzyme telomerase ensures the integrity of linear chromosomes by maintaining telomere length. As a hallmark of cancer, cell immortalization and unlimited proliferation is gained by reactivation of telomerase. However, a significant fraction of cancer cells instead uses alternative telomere lengthening mechanisms to ensure telomere function, collectively known as Alternative Lengthening of Telomeres (ALT). Although the budding yeast Naumovozyma castellii (Saccharomyces castellii) has a proficient telomerase activity, we demonstrate here that telomeres in N. castellii are efficiently maintained by a novel ALT mechanism after telomerase knockout. Remarkably, telomerase-negative cells proliferate indefinitely without any major growth crisis and display wild-type colony morphology. Moreover, ALT cells maintain linear chromosomes and preserve a wild-type DNA organization at the chromosome termini, including a short stretch of terminal telomeric sequence. Notably, ALT telomeres are elongated by the addition of ∼275 bp repeats containing a short telomeric sequence and the subtelomeric DNA located just internally (TelKO element). Although telomeres may be elongated by several TelKO repeats, no dramatic genome-wide amplification occurs, thus indicating that the repeat addition may be regulated. Intriguingly, a short interstitial telomeric sequence (ITS) functions as the initiation point for the addition of the TelKO element. This implies that N. castellii telomeres are structurally predisposed to efficiently switch to the ALT mechanism as a response to telomerase dysfunction.

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“…Recently, it has been shown that in Naumovozyma, an unconventional centromere has come into existence at a location that is largely distinct from that expected based on synteny with other Saccharomycetaceae species (Kobayashi et al, 2015). The Naumovozyma genus has been suggested as a model for comparative genomics and study of adaptive evolution due to the various phenotypic differences compared to other yeast species (Karademir Andersson & Cohn, 2017).…”

Section: Introductionmentioning

confidence: 99%

Loss of inner kinetochore genes is associated with the transition to an unconventional point centromere in budding yeast

Vijay

2020

PeerJ

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Background The genomic sequences of centromeres, as well as the set of proteins that recognize and interact with centromeres, are known to quickly diverge between lineages potentially contributing to post-zygotic reproductive isolation. However, the actual sequence of events and processes involved in the divergence of the kinetochore machinery is not known. The patterns of gene loss that occur during evolution concomitant with phenotypic changes have been used to understand the timing and order of molecular changes. Methods I screened the high-quality genomes of twenty budding yeast species for the presence of well-studied kinetochore genes. Based on the conserved gene order and complete genome assemblies, I identified gene loss events. Subsequently, I searched the intergenic regions to identify any un-annotated genes or gene remnants to obtain additional evidence of gene loss. Results My analysis identified the loss of four genes (NKP1, NKP2, CENPL/IML3 and CENPN/CHL4) of the inner kinetochore constitutive centromere-associated network (CCAN/also known as CTF19 complex in yeast) in both the Naumovozyma species for which genome assemblies are available. Surprisingly, this collective loss of four genes of the CCAN/CTF19 complex coincides with the emergence of unconventional centromeres in N. castellii and N. dairenensis. My study suggests a tentative link between the emergence of unconventional point centromeres and the turnover of kinetochore genes in budding yeast.

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Naumovozyma castellii: an alternative model for budding yeast molecular biology

Cited by 12 publications

References 65 publications

Rap1 and Cdc13 have complementary roles in preventing exonucleolytic degradation of telomere 5′ ends

Rap1 and Cdc13 have complementary roles in preventing exonucleolytic degradation of telomere 5′ ends

Alternative Lengthening of Telomeres in the Budding Yeast Naumovozyma castellii

Loss of inner kinetochore genes is associated with the transition to an unconventional point centromere in budding yeast

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