[The Effects of the Hydrogen Sulfide Donor GYY4137 on the Proteasome Pool of Colorectal Cancer Cells].

Cancer cells are characterized by an increased level of metabolism and are highly dependent on the correct functioning of the processes that ensure homeostasis. Reactive sulfur species (RSS) are important molecular modulators of metabolic processes in both healthy and tumor cells. The effect of RSS and, in particular, H2S, on key cellular systems, including the ubiquitin-proteasome system (UPS), which provides the destruction of most intracellular proteins, has been shown. The main components of the UPS are proteasomes, multisubunit protein complexes, within which proteolysis occurs. At the same time, data on the effect of H2S directly on the pool of proteasomes in tumor cells are insufficient. Here, we studied the effect of incubation of SW620B8-mCherry colorectal adenocarcinoma cells expressing a fluorescently labeled proteasome subunit with 50, 100, and 200 µM of the hydrogen sulfide donor GYY4137. The effect of the substance on the proteasome pool was assessed 6, 24, 48, and 72 h after administration. It was shown that the chymotrypsin-like and caspase-like proteasome activity decreases in cells incubated with 200 µM of the GYY4137 for 24 h. This coincided with an increase in the expression of proteasome subunit genes. In lysates of cells incubated with 200 µM GYY4137 for 48 h an increase in the content of the constitutive ß5 subunit was observed and the activity of proteasomes leveled off. Following prolonged incubation with GYY4137 (72h), an increase in the expression levels of some proteasome genes was also observed, although this did not have a significant effect on the activity and subunit composition of proteasomes. Thus, the obtained data indicate the modulation of proteasome activity by the hydrogen sulfide donor and the effect of GYY4137 on transcription and translation of proteasome genes.

[Herpes viruses and human papillomavirus in prostate cancer: first results].

INTRODUCTION: Benign prostatic hyperplasia (BPH) and prostate cancer (PCa) are among the most common urological diseases in men. It has been repeatedly suggested that viral infection plays an important role in prostate carcinogenesis. AIM: To assess the relationship between viral infection and PCa, as well as the clinical and morphological features of BPH and PCa. MATERIALS AND METHODS: A total of 98 patients undergoing treatment for BPH (n=48) or PCa (n=50) between 2019 and 2021 were included in the study. Real-time PCR on the surgical specimens for human papillomaviruses (HPV), herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2), cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes virus type 6 (HSV-6) was performed. RESULTS: In patients with PCa, viruses in prostate tissue were found more often compared to those with BPH (50.0 vs. 31.3%, respectively, p=0.046.) The most common virus in both PCa and BPH was EBV (22.0 vs. 16.7%, respectively). The second most common virus in patients with PCa was HSV-6 (20.0%), which was not detected in any men with BPH (p=0.003). There was a trend toward higher prevalence of CMV among patients with PCa (16.0% vs. 4.2%), but the difference was not significant (p=0.09). There was no association of viral infection with clinical and morphological features. CONCLUSIONS: The resulting trend toward a higher prevalence of HSV-6 and CMV in patients with PCa compared to those with BPH creates the prerequisites for further study of viruses in prostate diseases involving a larger cohort, which will provide an idea of the multi-stage process of malignant transformation and, possibly, open new therapeutic options for prevention and treatment.

[Changes in the Activities and Contents of Individual Forms of Proteasomes in Samples of the Cerebral Cortex during Pathology Development in 5xFAD Mice].

The ubiquitin-proteasome system (UPS) provides hydrolysis of most intracellular proteins in proteasomes. There are various forms of proteasomes that differ, among other things, in the set of proteolytic subunits and the presence of activators. Alzheimer's disease (AD) is characterized by disturbances in the functional state of the UPS. At the same time, an increase in the expression of certain forms of proteasomes, in particular, proteasomes containing immune subunits (nonconstitutive proteasomes), has been shown. Here, we studied dynamic changes in the expression of catalytic proteasome subunit genes and corresponding proteins in the cerebral cortex of animals using a mouse model of AD (5xFAD transgenic mice). Increases by 4 and 6 folds in transcripts of the PSMB9 and PSMB8 genes encoding immune proteasome subunits were detected, as well as a significant increase in the content of immune ß-subunits (by 2.8 folds, ß1i; 2.2 folds, ß2i) in samples from 5xFAD mice at the age of 380 days, compared with samples from mice at 60 days of age. Moreover, the activation of both 20S and 26S proteasomes containing immune subunits were revealed in samples from 380 days old 5xFAD mice by electrophoresis in native conditions. This indicates activated synthesis of the immune subunits and assembly of nonconstitutive proteasomes at the terminal stage of pathology development. The obtained data, in combination with the available literature, indicate that the activation of nonconstitutive proteasomes is a universal phenomenon characteristic of various animal models of AD, which may reflect both the development of neuroinflammation and adaptive processes in tissues induced by the accumulation of toxic protein aggegates.

[Dynamic Changes in the Activities and Contents of Particular Proteasome Forms in the Cerebral Cortex of C57BL/6 Mice during Aging].

Proteasomes are key components of the ubiquitin-proteasome system. Various forms of proteasomes are known. During aging, disturbances in the functioning of proteasomes have been revealed, as well as increased expression of their particular forms. Considering these data, we studied the expression of genes encoding the constitutive and immune subunits of proteasomes in cerebral cortex samples from C57BL/6 mice at the ages of 60, 190, 380, and 720 days. In addition, the contents of constitutive and immune proteasome subunits, chymotrypsin-like and caspase-like activities of proteasome pools, as well as the activity of the ß5i immune subunit were studied in tissue homogenates. The chymotrypsin-like activity and the activity of the ß5i subunit of different forms of proteasomes separated by electrophoresis in native gel were characterized. Compared with samples from young animals, in the cerebral cortex of animals at an age of 720 days the following changes in the expression patterns of proteasome genes were revealed: a decreased expression of the PSMB5 gene encoding constitutive proteasome subunit ß5; increased expression of genes encoding immune proteasome subunits ß5i and ß1i. In tissue homogenates of aged mice, an increase in the content of immune subunits ß1i and ß2i was shown. In samples from old animals, chymotrypsin-like activity was decreased and a tendency to a decrease in caspase-like activity of proteasomes as well as the ß5i subunit activity was revealed. Analysis of the activity of native complexes in tissues obtained from old animals revealed decreased chymotrypsin-like activity of 26S and 20S proteasomes containing the ß5i subunit. Based on the obtained data, it can be assumed that changes in the pool of nonconstitutive proteasomes reflect aging-associated adaptive processes in the mouse brain.

[Hepatitis C Virus Nonstructural Protein 3 Increases Secretion of Interleukin-lbeta in HEK293T Cells with a Reconstructed NLRP3 Inflammasome].

The pathology of diseases arising from infections by viruses of Flaviviridae is largely determined by the development of systemic inflammation. The cytokines interleukin-1beta and interleukin-18 play a key role in triggering inflammation. Their secretion from cells, in its turn, is induced upon activation of inflammasomes. Activation of NLRP3 (NLR pyrin domain-containing family 3) inflammasomes was detected in cells infected with Flaviviridae. Some nonstructural proteins of these viruses have been shown to be able to activate or to inhibit the NLRP3 inflammasome, in particular, through interaction with its components. In this study, a functional NLRP3 inflammasome was reconstructed in human HEK293T cells and the effect of some nonstructural proteins of individual Flaviviridae viruses on it was studied. This model did not reveal any impact of nonstructural NS1 proteins of the West Nile virus, NS3 of hepatitis C virus, or NS5 of tick-borne encephalitis virus on the inflammasome components content. At the same time, in the presence of the NS1 of the West Nile virus and NS5 of the tick-borne encephalitis virus, the level of secretion of interleukin-1beta did not change, whereas in the presence of the NS3 protein of the hepatitis C virus, it increased by 1.5 times. Thus, NS3 can be considered as one of the factors of NLRP3 inflammasome activation and inflammatory pathogenesis in chronic hepatitis C virus infection.

Fatty Acid Profile of Juvenile Arctic Char (Salvelinus alpinus Complex) from Natural Ecosystems and Aquaculture.

Significant differences in the fatty acid composition of the muscle tissue of juvenile Arctic char Salvelinus alpinus (Linnaeus, 1758) from the natural habitat (Lake Sobach'e) and aquaculture, as well as juveniles of the anadromous form of char (malma) Salvelinus malma (Walbaum, 1792) from the Avacha River were found. The observed differences between aquaculture and wild juvenile char were associated with different food sources. The muscle tissue of juvenile char from natural habitat was characterized by significantly higher levels of fatty acids-biomarkers of diatoms, as well as biomarkers of marine copepods in the anadromous form. In the fatty acid composition of juvenile char from aquaculture, significantly higher levels of linoleic acid were revealed, as well as long-chain monounsaturated acids, the source of which could be aquaculture feed. The identified differences did not have a significant effect on the content of eicosapentaenoic and docosahexaenoic acids in the muscle tissue of juvenile aquaculture and wild char. The content of biochemically valuable omega 3 polyunsaturated fatty acids in juvenile char from natural ecosystems and aquaculture was similar.

[Urinary biomarkers of kidney injury in patients treated with anti-VEGF drugs].

BACKGROUND: Antiangiogenic drugs are widely used in oncological practice and are aimed at inhibiting angiogenesis. Despite the high antitumor efficacy, their use may be limited by nephrotoxicity, and therefore the search for early biomarkers of kidney damage remains relevant, which will preserve a favorable safety profile of therapy. AIM: To determine urinary biomarkers of tubular and podocyte damage in patients receiving treatment with antiangiogenic drugs. MATERIALS AND METHODS: The study included patients (n=50) who received intravenous anti-VEGF drugs (aflibercept, bevacizumab, ramucirumab) in various chemotherapy regimens. Concentrations of tubular damage markers KIM-1 (Kidney Injury Molecule-1) and NGAL (Neutrophil Gelatinase-Associated Lipocalin), hypoxia marker HIF-1 (Hypoxia-Inducible Factor 1-alpha) in urine samples were determined by enzyme-linked immunosorbent assay (ELISA) before treatment, and during 8 weeks of treatment. To assess the risk factors for kidney damage, a logistic regression analysis was performed with the inclusion of the main clinical and laboratory parameters. RESULTS: A decrease in the calculated GFR of CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration Formula) of less than 60 ml/min per 1.73 m2 at week 8 of treatment was noted in 42% of patients. An increase in NGAL, KIM-1, HIF-1 and nephrin in urine during the first two weeks of therapy predicted the development of renal damage by the 8th week of follow-up. When constructing ROC-curves, the high sensitivity and specificity of these urinary indicators as prognostic markers were established. Among the clinical and laboratory indicators, independent unfavorable prognostic factors of nephrotoxicity were an initial decrease in eGFR, a history of hypertension, an increase in the concentration of KIM-1 and HIF-1 in urine during the first two weeks of therapy. CONCLUSION: The predictors of renal damage in the treatment with antiangiogenic drugs were previously an increase in NGAL, KIM-1 and HIF-1 in urine during the first two weeks after the start of therapy.

[Surgical treatment of Zinner syndrome].

Zinners syndrome (SC) is a rare congenital disease characterized by ejaculatory duct obstruction, seminal vesicle cyst in combination with ipsilateral renal agenesis. This syndrome is due to development arrest of the Wolffian duct (mesonephros). Before the onset of sexual activity, the disease is asymptomatic. The main symptoms are nonspecific, including dysuria, urinary frequency, perineal and scrotal pain after ejaculation. A clinical case with the presentation of our own experience of surgical robot-assisted treatment of a patient with Zinners syndrome is presented in the article.

[Rpn4p without the DNA-Binding Domain Provides Saccharomyces cerevisiae Resistance to Oxidative Stress and Cycloheximide].

The ubiquitin-proteasome system is involved in the control of all essential molecular processes under normal conditions and the response of cells to stress. Rpn4p serves as a key transcriptional regulator of the proteasome in Saccharomycetes yeast and is also involved in the cellular response to various stresses. In addition to proteasomal genes, Rpn4 affects the expression of several hundred other genes, including genes involved in DNA repair and oxidative stress response. At the same time, the molecular mechanisms used by Rpn4 in controlling target genes and its functioning as a regulator of the cellular response to stress remain largely unclear. The aim of this work was to determine the Rpn4 domains required to ensure cell resistance to stress. It was shown that the N-terminal and central regions of the protein contain sites required for resistance to all types of stresses. The putative nuclear localization signal does not affect the functioning of Rpn4. Unexpectedly, a protein with the deletion of both zinc finger motifs that form the DNA-binding domain provides yeast resistance to oxidative stress and cycloheximide. Moreover, we showed that Rpn4 can be recruited to the promoter regions of the regulated genes even if they do not contain its binding sites. Based on these data, it can be assumed that Rpn4 is involved in gene regulation and the cellular response to stress due to protein-protein interactions.

Effect of Biocides on the Activity of Extracellular Enzymes Produced by Degrader Fungi from Technical Objects Used in Tropical Climates (Vietnam).

Activity of extracellular enzymes was assessed in 20 strains of microscopic fungi involved in biodegradation of technical objects exploited under tropical climate conditions (Vietnam). It was found that 19 strains possessed catalase activity, 18 strains had phenol oxidase activity, and eight strains had protease activity. The effect of industrial biocides on the activity of these enzymes was also assessed. The biocides Bior-1, Bioneutral A 10, and Bioneutral A 101 were shown to inhibit the enzymatic activity to various extent. All biocides inhibited extracellular catalase activity in most fungal strains studied. The inhibition of protease and phenol oxidase activity of same test strains was less pronounced. The response to biocides varied at the strain level; its characteristics could differ significantly even between strains of the same species. In several cases, it was observed that exposure to biocides resulted in an increase in enzyme activity.

[Super-selective prostatic artery embolization as minimally invasive surgical treatment in patients with BPH].

Benign prostatic hyperplasia (BPH) is a widespread socially significant disease. Minimally invasive surgical treatments can reduce the surgical and anesthetic risk. One of the most effective methods of minimally invasive surgical treatment of BPH is superselective prostatic artery embolization (prostatic artery embolization; PAE). PAE is a method with proven effectiveness and has been included in the clinical recommendations of the Ministry of health of the Russian Federation for the treatment of BPH since 2019.

[The effect of music embedded with binaural beats on heart rate parameters during nap]. / Vliyanie muzyki s effektom binaural'nykh bienii na parametry serdechnogo ritma cheloveka v protsesse dnevnogo sna.

OBJECTIVE: To test hypothesis that music embedded with binaural beats can boost activity of parasympathetic part of autonomic nervous system (PPANS) with the development of nap. MATERIAL AND METHODS: The power of high-frequency component of heart rate variability spectrum computed on successive 2-minute intervals during 20-minute nap was a comparison criterion. The criterion was compared during nap accompanied by music with embedded binaural beats (stimulus condition) and nap in silence (control condition). RESULTS AND CONCLUSION: Statistical comparison revealed the increase of PPANS activity during nap in stimulus condition vs. control condition. It is consistent with conclusions of other papers about positive effect of sound stimuli embedded with binaural beats on PPANS.

[Structures of the Mouse Central Nervous System Contain Different Quantities of Proteasome Gene Transcripts].

Proteasomes are multisubunit complexes that degrade most intracellular proteins. Three of the 14 subunits of the 20S proteasome, specifically ß1, ß2, and ß5, demonstrate catalytic activity and hydrolyze peptide bonds after acidic, basic, and hydrophobic amino acids, respectively. Within proteasome, the constitutive catalytic subunits ß1, ß2, and ß5 can be substituted by the immune ßli, ß2i, and ß5i subunits, respectively. However, proteasomes do not always contain all the immune subunits at once; some proteasomes contain both immune and constitutive catalytic subunits simultaneously. Incorporation of immune subunits modifies the pattern of peptides produced by proteasomes. This is essential for antigen presentation and cellular response to stress as well as for a number of intracellular signaling pathways. We have developed a quantitative PCR-based system for the determination of the absolute levels of murine constitutive and immune proteasome subunits gene expression. Using the obtained system, we have estimated the expression levels of genes encoding proteasome subunits in the mouse central nervous system (CNS) tissues. We have shown that the quantity of transcripts of proteasome catalytic subunits in different CNS structures differed significantly. These data allow us to assume that the studied brain regions can be divided into two groups, with relatively "high" (cerebral cortex and spinal cord) and "low" (hippocampus and cerebellum) levels of proteasome subunit genes expression. Moreover, it was possible to distinguish structures with similar and significantly different gene expression profiles of proteasome catalytic subunits. Thus, the gene expression profiles in the cortex, spinal cord, and cerebellum were similar, but different from the expression profile in the hippocampus. Based on the obtained data, we suggest that there are differences in the proteasome pool, as well as in the functional load on the ubiquitin-proteasome system in different parts of the CNS.

[Phenotyping of angiotensin-converting enzyme in the prostate in patients with prostate cancer and benign prostatic hyperplasia].

BACKGROUND: Angiotensin-converting enzyme (ACE) is expressed by all epithelial cells of the human body. Although the main proportion of ACE is synthesized by the lungs, in men, ACE is also secreted by the testes (testicular form), seminal vesicles and the prostate. In semen, the level of ACE is up to 50 times higher than in blood plasma. The substitution of highly specific epithelial cells of the prostate by tumor cells causes a dramatic decrease in ACE production by the prostate cells. AIM: To assess the possibility of using prostatic ACE as a new marker of prostate cancer (PCa). MATERIALS AND METHODS: ACE phenotyping in prostate of patients with PCa and benign prostatic hyperplasia (BPH) included measurement of the activity of two ACE substrates (HHL and ZPHL); calculation of the ratio of their hydrolysis rates (ZPHL/HHL ratio); quantitative assessment of the ACE immunoreactive protein, the ratio of the immunoreactive protein to the ACE activity, as well as the conformation of ACE using a panel of monoclonal antibodies (mAb) to different epitopes of ACE. RESULTS: ACE activity in tumor cells was markedly reduced and the ratio of immunoreactive ACE to its activity increased. The ratio of the hydrolysis rates of two substrates (ZPHL/HHL ratio) in patients with PCa increased compared to control group, while it was not observed in the vast majority of patients with BPH. There were several tissue samples with a histological diagnosis of BPH, but ACE phenotype was typical for PCa. DISCUSSION: Since a decrease in ACE activity was found in all patients with PCa, we suggest that it may serve as a reliable and early marker of the tumor development. Changes in the ACE phenotype, which are typical for PCa, but found in patients with BPH, may indicate earlier malignant changes in prostate cells, which are not visible on routine prostate biopsy. CONCLUSIONS: ACE activity and its conformation in prostatic biopsies has the potential to be an early biomarker or a differential criterion for PCa. In PCa, the ACE activity in the prostate is significantly reduced, and the ZPHL/HHL ratio is markedly increased in comparison to control group. However, there were no such changes in patients with BPH. In hyperplastic processes of the prostate (BPH, PCa), there is a change in ACE sialylation, which is accompanied by an increase in the binding of ACE to mAb 3F10 compared to the control group. Patients with negative biopsy result, but properties of prostate ACE, which are typical for PCa, require close follow-up, since they may have an increased risk of subsequent developing PCa. However, due to a small sample of patients, the diagnostic potential of prostate ACE for PCa and BPH requires to be validated in a larger number of patients to confirm its predictive accuracy.

[Super-selective embolisation of bladder arteries for treatment of patients with bladder tumors complicated by recurrent macrohematuria].

The prevalence of bladder cancer in Russia over the past 10 years has increased from 49.6 to 74.1 patients per 100,000 population. Hematuria is a life-threatening complication and one of the common causes of mortality in advanced stages of bladder cancer. Conservative methods of hemostasis do not always allow to achieve a stable effect. In addition, in the cases of intractable bleeding, the patients may require surgical treatment. Due to the prevalence of patients with a high anesthetic risk group in bladder cancer patients cohort, the minimally invasive hemostasis technologies are more preferable. This review is devoted to one of such methods - superselective embolization of the urinary bladder arteries.

[Audiological profile of patients with SARS-Co-V-2 PCR-positive cases]. / Audiologicheskii profil' patsientov pri zabolevanii, vyzvannom virusom SARS-CoV-2.

COVID-19 is a new pandemic caused by a novel coronavirus, SARS-CoV-2. COVID-19 has spread throughout China and received worldwide attention. On 11 February 2020, World Health Organization (WHO) officially declared COVID-19. The clinical symptoms of COVID-19 patients may vary, more often include symptoms affected by upper and lower respiratory tract damage. In ENT practice it is used to mention rhinitis, sore throat, anosmia/hyposmia. The effect of COVID-19 is an interesting issue in audiology. There were 78 patients who were confirmed positive for COVID-19 PCR-positive cases and 30 normal non-infected subjects in our study. The patients were divided into two groups according to severity their clinical symptoms from asymptomatic COVID-19 PCR-positive cases to severe form. All patients underwent audiological evaluation included tympanometry, acoustic threshold and transient evoked otoacoustic emission (TEOAE). Although hearing sensitivity was normal among some participants, it was statistically proved that TEOAEs could pick up subtle deterioration in the outer hair cells functions and impact on the cochlear.

[Hyper-Resistance of the Bacillus licheniformis 24 Strain to Oxidative Stress Is Associated with Overexpression of Enzymatic Antioxidant System Genes].

At the International Space Station (ISS), artificial living conditions are created and maintained to satisfy human needs, these conditions are also favorable for the growth of numerous microorganisms, molds and bacteria. Among the microorganisms detected on the ISS are those from the automicroflora of crew members, and a significant number of spore-forming bacteria. In most cases, this group of microorganisms gives rise to strains that are able to colonize, grow and reproduce on interior materials and equipment of stations, and may be involved in biodestructive processes. These bacteria show increased resistance to various stress factors, for example, DNA-damaging and oxidizing agents. The molecular mechanisms of this resistance to stress are poorly understood. As part of the sanitary-microbiological monitoring of the ISS habitat, the Bacillus licheniformis 24 strain was isolated. Here, we demonstrated that this strain has increased resistance to hydrogen peroxide and Paraquat when compared to the "terrestrial" B. licheniformis B-10956 strain. B. licheniformis 24 overexpressed genes encoding enzymes that neutralize reactive oxygen species, such as KatX catalase and the superoxide dismutases SodA and SodF. Apart from this, in comparison with B. licheniformis B-10956, of B. licheniformis 24 cells had lower hydrogen sulfide production that was associated with sharply reduced expression of the cysIJ operon that encodes sulfite reductase. The results indicate that enzymatic antioxidant protective systems make a more significant contribution to the hyper-resistance of Bacillus strains to oxidizing agents than components of non-enzymatic systems, such as hydrogen sulfide.

[Successful treatment of an aortoduodenal fistula after operation on the abdominal portion of the aorta]. / Uspeshnoe lechenie aorto-duodenal'noi fistuly posle operatsii na briushnom otdele aorty.

Gastrointestinal haemorrhage is a common cause of emergency admission of patients to surgical hospitals. Within the structure of nosological entities, not unreasonably referred to the rarest causes of gastrointestinal bleeding is the formation of an aortointestinal fistula whose early diagnosis is of paramount importance. The clinical picture may be different but it is mostly represented by gastrointestinal haemorrhage. The incidence of gastrointestinal fistulas following a surgical intervention ranges from 0.6 to 2.3%. Unless timely diagnosed and with incorrect therapeutic decision-making, the mortality rate amounts to 90%. In this article we present a clinical case report regarding successful treatment of a patient presenting with a secondary aortoduodenal fistula occurring 5 years after previously performed aortofemoral bypass grafting and complicated by relapsing intestinal bleeding and acute ischaemia of the right lower extremity.

[Biotechnological Potential of the Bacillus subtilis 20 Strain].

Bacillus subtilis bacteria play an important role in veterinary medicine, medicine, and biotechnology, and the permanently growing demand for biotechnological products fuels the improvement of the properties of biotechnological strains. B. subtilis strains with improved characteristics maybe obtained by rational design and the directed evolution technologies, or be found among newly described strains. In the course of the long-term microbiome composition studies in the Russian segment of the International Space Station, the B. subtilis 20 strain was isolated, this strain shows the capacity for rapid growth and considerable biomass accumulation, as well as increased resistance to acidification of the environment in comparison to the "terrestrial" B. subtilis 168 strain. What is more, B. subtilis 20 is hyperresistant to the DNA and protein damaging factors that are linked to the overexpression of the genes controlling DNA repair, hydrogen sulfide production, and reactive oxygen species neutralization. The described properties of B. subtilis 20 are indicative of its considerable potential as a promising producer of biologically active compounds.

[Evolution of the System of Coordinate Regulation of Proteasomal Gene Expression in the Yeast Class Saccharomycetes].

The 26S proteasome is a multisubunit ATP-dependent protease complex and is necessary for the normal function of the eukaryotic cell and its survival in stress. Twenty years ago, we, in collaboration with German researchers, were the first to experimentally describe a system for coordinated regulation of proteasomal gene expression in the yeast Saccharomyces cerevisiae. This system consists of the ScRpn4 transcription factor and its binding site, called PACE. Based on the results of a bioinformatics search in the first sequenced yeast genomes, Rpn4-like proteins and PACE-like elements were postulated for other species of the class Saccharomycetes. We experimentally characterized Rpn4-like proteins in the biotechnologically significant yeast species Komagataella pfaffii (Pichia pastoris), Yarrowia lipolytica, and Debaryomyces hansenii and the opportunistic yeast Candida glabrata. As ample information accumulates for the genome sequences of new yeast species and strains, the question arises as to how diverse the regulatory system of proteasomal genes is in terms of structure and likely mechanisms of function. In this work, a bioinformatics search for Rpn4-like proteins and PACE-like elements was conducted in 3111 strains belonging to 427 yeast species of the class Saccharomycetes. It was shown that only the DNA-binding domain is conserved among Rpn4-like proteins, in accordance with conservation of PACE elements. Certain systems were found to contain more than one Rpn4-like protein with structural differences in the DNA-binding domain or to include an autoregulation of the genes for Rpn4-like proteins. Given that Rpn4-like proteins and proteasomes play a role in the cell response to stress, the diversity of systems for the regulation of proteasomal genes was assumed to corresponds to adaptation of organisms to their living environments.