Main achievements:

The most important achievements of the Laboratory of Molecular Genetics involve the study of prion and non-prion amyloids in the yeast Saccharomyces cerevisiae. We have demonstrated that the translation termination factor eRF3 manifests properties characteristic of the prion proteins of mammals.

We also identified the regions responsible for the prion properties and the translation termination activity of eRF3. Novel approaches to the analysis of prion particles structure were developed and the mechanism of their propagation and inheritance was suggested and supported by subsequent experiments. We have elucidated the role of the Hsp104 chaperone in yeast prion replication. The obtained data allowed us to define yeast prion as amyloids susceptible to fragmentation. The phenomenon of strain variability of yeast prions was demonstrated and studied and the molecular bases of prion interspecies transmission barriers were established.

We also have described the phenomenon of interdependence of amyloid formation, which allowed us to reveal the source of human huntingtin toxicity in yeast. Our group was the first to demonstrate that the yeast translation termination machinery is involved in controlling mRNA stability and also participates in the organization of the cytoskeleton and cell cycle regulation.

We have also identified and studied nonsense codon specific and non-specific modulators of translation termination efficiency.

A suite of the plasmid vectors and appropriate recipient strains of Hansenula polymorpha was created, which allowed molecular genetic studies with this yeast species. The behavior of replicative and integrative plasmids in H. polymorpha cells was studied. Particularly, recombinational rearrangements of transforming DNA were observed and characterized. The role of vesicular intracellular transport in maintaining Са²⁺ homeostasis was discovered and the relationship between the homeostasis of Са²⁺ ions and the control of cell cycle was revealed.

Selected publications:

1. Bidiuk VA, Alexandrov AI, Valiakhmetov AY. Extracellular pH and high concentration of potassium regulate the primary necrosis in the yeast Saccharomyces cerevisiae. Arch Microbiol. 2021 Dec 20;204(1):35. doi:10.1007/s00203-021-02708-6. PMID: 34927223;
2. Kushnirov VV, Dergalev AA, Alexandrov AI. Amyloid Fragmentation and Disaggregation in Yeast and Animals. Biomolecules. 2021 Dec 15;11(12):1884. doi: 10.3390/biom11121884. PMID: 34944528; PMCID: PMC8699242;
3. Egorov AA, Makeeva DS, Makarova NE, Bykov DA, Hrytseniuk YS, Mitkevich OV, Urakov VN, Alexandrov AI, Kulakovskiy IV, Dmitriev SE. Ribo-Seq and RNA-Seq of TMA46(DFRP1) and GIR2(DFRP2) knockout yeast strains. F1000Res. 2021 Nov 16;10:1162. doi: 10.12688/f1000research.74727.1.PMID: 34900236; PMCID: PMC8637242;
4. Egorov AA, Alexandrov AI, Urakov VN, Makeeva DS, Edakin RO, Kushchenko AS, Gladyshev VN, Kulakovskiy IV, Dmitriev SE. A standard knockout procedure alters expression of adjacent loci at the translational level. Nucleic Acids Res. 2021 Nov 8;49(19):11134-11144. doi: 10.1093/nar/gkab872. PMID: 34606617; PMCID: PMC8565318;
5. Grosfeld EV, Bidiuk VA, Mitkevich OV, Ghazy ESMO, Kushnirov VV, Alexandrov AI. A Systematic Survey of Characteristic Features of Yeast Cell Death Triggered by External Factors. J Fungi (Basel). 2021 Oct 20;7(11):886. doi: 10.3390/jof7110886. PMID: 34829175; PMCID: PMC8626022;
6. Karginov AV, Alexandrov AI, Kushnirov VV, Agaphonov MO. Perturbations in the Heme and Siroheme Biosynthesis Pathways Causing Accumulation of Fluorescent Free Base Porphyrins and Auxotrophy in Ogataea Yeasts. J Fungi (Basel). 2021 Oct 19;7(10):884. doi: 10.3390/jof7100884. PMID: 34682305; PMCID: PMC8540529;
7. Dergalev AA, Urakov VN, Agaphonov MO, Alexandrov AI, Kushnirov VV. Dangerous Stops: Nonsense Mutations Can Dramatically Increase Frequency of Prion Conversion. Int J Mol Sci. 2021 Feb 3;22(4):1542. doi: 10.3390/ijms22041542. PMID: 33546497; PMCID: PMC7913716;
8. Bidiuk VA, Agaphonov MO, Alexandrov AI. Modulation of green to red photoconversion of GFP during fluorescent microscopy by carbon source and oxygen availability. Yeast. 2021 May;38(5):295-301. doi: 10.1002/yea.3543. Epub 2020 Dec 14. PMID: 33295038;
9. Alexandrov AI et al. (2019) Analysis of novel hyperosmotic shock response suggests «beads in liquid» cytosol structure;
10. Alexandrov AI, Dergalev AA.  (2019). Increasing throughput of manual microscopy of cell suspensions using solid medium pads. MethodsX;
11. Urakov, V. N., Mitkevich, O. V, Dergalev, A. A. and Ter-Avanesyan, M. D. (2018). The Pub1 and Upf1 Proteins Act in Concert to Protect Yeast from Toxicity of the [PSI(+)] Prion. Int. J. Mol. Sci. 19;
12. Karginov, A. V, Fokina, A. V, Kang, H. A., Kalebina, T. S., Sabirzyanova, T. A., Ter-Avanesyan, M. D. and Agaphonov, M. O. (2018). Dissection of differential vanadate sensitivity in two Ogataea species links protein glycosylation and phosphate transport regulation. Sci. Rep. 8, 16428;
13. Anisimova, A.S., Alexandrov, A.I., Makarova, N.E., Gladyshev, V.N., and Dmitriev, S.E. (2018). Protein synthesis and quality control in aging. Aging (Albany. NY). 10, 4269–4288;
14. E Keinan, Ayelet-Chen Abraham , A Cohen , A Alexandrov, R Mintz , M Cohen, D Reichmann , D Kaganovich, Y Nahmias  (2018) High-Reynolds Microfluidic Sorting of Large Yeast Populations. Scientific Reports;
15. Urakov, V. N., Mitkevich, O. V, Safenkova, I. V and Ter-Avanesyan, M. D. (2017). Ribosome-bound Pub1 modulates stop codon decoding during translation termination  in yeast. FEBS J. 284, 1914–1930;
16. Serpionov G V., Alexandrov AI, Ter-Avanesyan MD (2016) Distinct mechanisms of mutant huntingtin toxicity in different yeast strains. FEMS Yeast Research: fow102. doi:10.1093/femsyr/fow102.