Yuliya S. Zaitseva, Ekaterina V. Kropocheva, Andrey V. Kulbachinskiy, Daria M. Gelfenbein
{"title":"Programmable DNA Cleavage by Cyanobacterial Argonaute Proteins","authors":"Yuliya S. Zaitseva, Ekaterina V. Kropocheva, Andrey V. Kulbachinskiy, Daria M. Gelfenbein","doi":"10.1134/S0006297925602680","DOIUrl":"10.1134/S0006297925602680","url":null,"abstract":"<p>Argonaute proteins are an evolutionarily conserved family of proteins capable of recognizing and cleaving specific nucleic acid sequences using complementary guide molecules. Eukaryotic Argonautes play a key role in RNA interference by utilizing short RNAs of various classes to recognize target mRNAs. Prokaryotic Argonautes are much more diverse and most of them recognize DNA targets. The search for new Argonautes that would be active under varying conditions is important for both understanding their functions and developing new tools for genetic technologies. Many previously studied Argonautes exhibit low activity at low and moderate temperatures. To overcome this limitation, we isolated and studied two Argonaute proteins from psychrotolerant cyanobacteria, CstAgo from <i>Cyanobacterium stanieri</i> and CspAgo from <i>Calothrix</i> sp<i>.</i> Both proteins use short DNA guides to recognize and cleave DNA targets. CstAgo displayed no specificity for the 5′-end structure of the guide, while CspAgo demonstrated a weak preference for the 5′-terminal nucleotide. CstAgo was highly active and capable of cleaving single-stranded DNA at temperatures from 10 to 50°C. CspAgo was more cold-sensitive but cleaved double-stranded plasmid DNA using specific guides. Therefore, the studied proteins can be potentially used for DNA manipulations under a wide range of conditions.</p>","PeriodicalId":483,"journal":{"name":"Biochemistry (Moscow)","volume":"90 9","pages":"1288 - 1300"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1134/S0006297925602680.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rinat A. Khannanov, Ivan V. Chicherin, Mariya V. Baleva, Sergey A. Levitskii, Ruslan A. Vasilev, Ulyana E. Piunova, Piotr Kamenski
{"title":"Approaches to Humanization of Mitochondrial Proteins in Saccharomyces cerevisiae on the Example of Replacing the Yeast Mitochondrial Translation Termination Factor MRF1 with Its Human Homologues","authors":"Rinat A. Khannanov, Ivan V. Chicherin, Mariya V. Baleva, Sergey A. Levitskii, Ruslan A. Vasilev, Ulyana E. Piunova, Piotr Kamenski","doi":"10.1134/S0006297925601418","DOIUrl":"10.1134/S0006297925601418","url":null,"abstract":"<p>Mitochondrial translation is a highly specialized process of synthesizing mitochondrially encoded proteins, mainly the components of the oxidative phosphorylation system. It involves four key stages: initiation, elongation, termination, and recycling of mitochondrial ribosomes. Each of these stages is regulated by a specific set of translation factors, most of which are encoded by the nuclear genome and imported into mitochondria. The termination of mitochondrial translation in yeast (<i>Saccharomyces cerevisiae</i>) is carried out by the MRF1 release factor. This nuclear-encoded factor is crucial for ensuring accurate protein synthesis within the organelle, as it recognizes stop codons and facilitates the release of completed polypeptide chains from the ribosome. In addition to this main function, MRF1 participates in maintaining mitochondrial genome stability. The aim of this study was to investigate the capacity of human homologues, hMTRF1, hMTRF1A, and mitoribosome rescue factors hMTRFR and hMRPL58, to compensate for the absence of the yeast mitochondrial translation termination factor MRF1 in <i>S. cerevisiae</i> cells. The results obtained suggest that human orthologues of MRF1, such as hMTRF1 and hMTRF1A, can contribute to maintaining the integrity of the yeast mitochondrial genome. However, they do not fully replace the function of MRF1, as they do not restore normal respiration of the mutant yeast strains.</p>","PeriodicalId":483,"journal":{"name":"Biochemistry (Moscow)","volume":"90 9","pages":"1240 - 1251"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Overall Equation of Photosynthesis and the Source of Molecular Oxygen: Methodological Analysis of a Formal Paradox","authors":"Vasily V. Ptushenko","doi":"10.1134/S0006297925600450","DOIUrl":"10.1134/S0006297925600450","url":null,"abstract":"<p>The article addresses a formal paradox related to the formation of molecular oxygen during photosynthesis. Following the studies of van Niel in the early 1930s, it has become clear that in the oxygenic photosynthesis, molecular oxygen originates from water rather than carbon dioxide. However, the overall equation of photosynthesis, <i>n</i>CO<sub>2</sub> + <i>n</i>H<sub>2</sub>O → (CH<sub>2</sub>O)<sub>n</sub> + <i>n</i>O<sub>2</sub>, suggests that the amount of oxygen produced exceeds what could be derived from the water molecules involved. This paradox can be resolved by analyzing the light and dark reactions of photosynthesis, which ultimately result in the incorporation of carbon from CO<sub>2</sub> into carbohydrates and production of molecular oxygen. Despite its simplicity, the solution is not immediately obvious. One reason is that in the scientific and educational literature, the dark reactions of photosynthesis are often depicted schematically, without precise specification of all components involved. The author argues that analyzing this paradox and underlying physicochemical principles of photosynthesis can be valuable for students specializing in biochemistry.</p>","PeriodicalId":483,"journal":{"name":"Biochemistry (Moscow)","volume":"90 9","pages":"1301 - 1309"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tatiana A. Timakova, Mikhail V. Karpov, Vera M. Nikolaeva, Daria N. Tekucheva, Andrei A. Shutov, Victoria V. Fokina, Marina V. Donova
{"title":"17β-Hydroxysteroid Dehydrogenase from the Fungus Cochliobolus lunatus: Biosynthesis in Mycolicibacterium neoaurum Actinobacterial Cells and Functional Characterization","authors":"Tatiana A. Timakova, Mikhail V. Karpov, Vera M. Nikolaeva, Daria N. Tekucheva, Andrei A. Shutov, Victoria V. Fokina, Marina V. Donova","doi":"10.1134/S0006297925601959","DOIUrl":"10.1134/S0006297925601959","url":null,"abstract":"<p>17β-Hydroxysteroid dehydrogenase (17β-HSD) is an enzyme used in biotechnology for producing testosterone from phytosterol. Heterologous 17β-HSD from the fungus <i>Cochliobolus lunatus</i> catalyzes NADPH-dependent reduction of the 17-oxo group of androstenedione/androstadienedione formed in mycolicibacterial cells as a result of the inherent polyenzymatic process of side chain oxidation of phytosterols, yielding testosterone/Δ<sup>1</sup>-dehydrotestosterone, respectively. The object of this study was heterologous 17β-HSD from the fungus <i>C. lunatus</i> (17β-HSD<sub>Cl</sub>) with a 6×His tag (6×His-17β-HSD<sub>Cl</sub>), synthesized in the cells of actinobacteria <i>Mycolicibacterium neoaurum</i>. Isolation and purification of the recombinant enzyme were performed using affinity chromatography. The 6×His-17β-HSD<sub>Cl</sub> enzyme preparation exhibited the highest activity toward androstenedione. Activity of the 6×His-17β-HSD<sub>Cl</sub> depended on NADPH and was observed in the pH range from 6.0 to 9.0 with an optimum at pH 7.0. Analysis of kinetic characteristics showed that the properties of the heterologous enzyme 6×His-17β-HSD<sub>Cl</sub> synthesized in <i>M. neoaurum</i> cells are comparable with those reported for the 17β-HSD enzyme isolated from the fungus <i>C. lunatus</i>, as well as for the recombinant 17β-HSD<sub>Cl</sub> enzymes synthesized in <i>Escherichia coli</i> and <i>Mycolicibacterium smegmatis</i> cells. The results expand our knowledge on microbial 17β-HSDs and suggest potential for the use of the recombinant <i>M. neoaurum</i> strains expressing a codon-optimized cDNA sequence encoding 17β-HSD<sub>Cl</sub> from the fungus <i>C. lunatus</i> for producing testosterone from phytosterol.</p>","PeriodicalId":483,"journal":{"name":"Biochemistry (Moscow)","volume":"90 9","pages":"1264 - 1276"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anne V. Yagolovich, Alina A. Isakova, Ekaterina V. Kukovyakina, Yuan Zijian, Anastasiia S. Fedulova, Arina V. Avakiants, Alexey K. Shaytan, Dmitry A. Dolgikh, Mikhail P. Kirpichnikov, Marine E. Gasparian
{"title":"Novel Fusion Protein Based on DR5-Specific TRAIL Variant with Enhanced Antitumor Properties","authors":"Anne V. Yagolovich, Alina A. Isakova, Ekaterina V. Kukovyakina, Yuan Zijian, Anastasiia S. Fedulova, Arina V. Avakiants, Alexey K. Shaytan, Dmitry A. Dolgikh, Mikhail P. Kirpichnikov, Marine E. Gasparian","doi":"10.1134/S0006297925602096","DOIUrl":"10.1134/S0006297925602096","url":null,"abstract":"<p>The cytokine TRAIL is distinguished by its remarkable ability to preferentially induce apoptosis in transformed, but not in normal, cells. The recombinant TRAIL extracellular domain and other first-generation agonists of DR4 and DR5 death receptors (DRs) have shown very limited antitumor activity in clinical trials. To enhance the antitumor effect, we developed the multitarget recombinant fusion protein SRH-DR5-B-p48 based on the DR5-selective TRAIL variant DR5-B to simultaneously affect tumor cells (DR5-B-mediated apoptosis) and tumor microenvironment, in particular, to suppress angiogenesis. For this purpose, we modeled and produced the recombinant SRH-DR5-B-p48 fusion protein containing antagonistic synthetic peptides (SRH and p48) to VEGFR2 and FGFR1 receptors, respectively. Analysis of molecular trajectories using molecular dynamics methods showed that the SRH and p48 peptides form non-specific temporary contacts with the DR5-B domain. Using enzyme-linked immunosorbent assay, we showed that SRH-DR5-B-p48 was similar to DR5-B in its affinity for the death receptor DR5 and demonstrated a high affinity for VEGFR2 and FGFR1 with nanomolar dissociation constants. SRH-DR5-B-p48 killed tumor cells of various origin more efficiently than DR5-B and destroyed tumor-like structures in 3D cell models, as well as inhibited FGF2-mediated stimulation of fibroblast proliferation. Therefore, the SRH-DR5-B-p48 fusion protein can be considered as a promising agent for the therapy of solid tumors of various origin.</p>","PeriodicalId":483,"journal":{"name":"Biochemistry (Moscow)","volume":"90 9","pages":"1277 - 1287"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Membrane Guanylyl Cyclases as Potential Targets for Guanylin Action","authors":"Elizaveta D. Snigireva, Olga V. Smirnova","doi":"10.1134/S000629792560156X","DOIUrl":"10.1134/S000629792560156X","url":null,"abstract":"<p>Guanylins are intestinal natriuretic peptides that regulate water and electrolyte balance in the intestine and kidney. Their primary receptor is membrane guanylyl cyclase C (GC-C), while alternative functions related to feeding behavior and olfactory preferences are mediated by guanylyl cyclase D (GC-D) expressed exclusively in olfactory neurons. Evidence suggests existence of unidentified receptors activated by guanylin peptides in the absence of GC-C that affect sodium metabolism. Some of these receptors trigger the cGMP-dependent signaling pathways typical exclusively for guanylyl cyclases. This review provides a comparative analysis of the existing data on different membrane receptor guanylyl cyclases, including early discoveries and contemporary research, focusing on their potential as guanylin targets.</p>","PeriodicalId":483,"journal":{"name":"Biochemistry (Moscow)","volume":"90 9","pages":"1169 - 1187"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nadezhda S. Pavlova, Tatyana V. Neretina, Olga V. Smirnova
{"title":"Expression of Ion Transporter Genes in Gills and Intestine of Male and Female Gasterosteus aculeatus L. Three-Spined Sticklebacks during Freshwater Adaptation","authors":"Nadezhda S. Pavlova, Tatyana V. Neretina, Olga V. Smirnova","doi":"10.1134/S0006297925601054","DOIUrl":"10.1134/S0006297925601054","url":null,"abstract":"<p>In euryhaline fish species, including the three-spined stickleback, a key physiological response to freshwater adaptation aimed at maintaining osmotic homeostasis is enhancement of ion uptake from the environment and reduction of ion loss. Hormone prolactin, a central regulator of this process, primarily targets gills and intestine. Our previous work demonstrated that in the model of freshwater adaptation in sticklebacks prolactin expression and sensitivity of osmoregulatory tissues to prolactin differ between the males and females. In the present study, we measured expression levels of the genes encoding α1a and α3a subunits of Na<sup>+</sup>/K<sup>+</sup>-ATPase, as well as ion transporters NKCC1a, NKCC2, NCC, and NHE2, in the gill and intestinal tissues of the male and female three-spined sticklebacks (<i>Gasterosteus aculeatus</i> L.) under conditions of acute (24 h) and chronic (72 h) freshwater adaptation, relative to the control conditions. During the freshwater adaptation, females, but not males, exhibited increased intestinal expression of <i>nhe2</i> and <i>atp1a3</i> genes (as well as of the ratio of <i>atp1a1</i>/<i>atp1a3</i> expression), and the <i>nkcc1a</i> gene, along with the decreased expression of the <i>nkcc2</i> gene. In contrast, only males showed increase in the <i>ncc</i> gene expression in the intestine. In both sexes, exposure to fresh water led to the significant decrease in the <i>nkcc1a</i> gene expression in the gills. These findings support our hypothesis of sex-dependent plasticity in osmoregulatory function in sticklebacks, with females exhibiting a more pronounced response. This pattern further aligns with the previously reported stronger activation of the prolactin axis in the females under freshwater adaptation conditions.</p>","PeriodicalId":483,"journal":{"name":"Biochemistry (Moscow)","volume":"90 9","pages":"1227 - 1239"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Chemistry of the Joint Origin and Evolution of Life, Death, and Aging","authors":"Aleksei G. Golubev","doi":"10.1134/S0006297925601674","DOIUrl":"10.1134/S0006297925601674","url":null,"abstract":"<p>Reviewing published concepts on the chemical interactions between small molecules implicated in the origin of life suggests that their chemical properties have included not only those that might have been suitable for metabolic pathways. Some of the immanent “excessive” potencies of molecules make them able to form covalent adducts with proteins and nucleic acids. The accumulation of macromolecules damaged in this way could decrease the viability of protocells with increasing age. Thus, aging (senescence) could emerge concomitantly with life as its chemical heritage. Moreover, the exponential increase in mortality with age (the Gompertz law) could emerge when the kinetics of molecular disintegration according to the Arrhenius equation (disintegration rate depends exponentially on varying temperature at a constant activation barrier) was inherited by the kinetics of protocells dying out in their populations, the role of the independent variable passing from temperature, which was virtually constant on the Calvin scale, to viability. The cooperation of these two chemical heritages was enough to eliminate effectively old living objects and to make any evolved program of aging needless. Therefore, aging had not resulted from the biological evolution but rather has been and still is its independent factor. All this was possible without oxygen, which could only modify, rather than form <i>de novo</i>, the primary chemical driving force of aging. With all that, the energy benefits of aerobic metabolism have provided for the advent of multicellular organisms, in particular, those featuring massive extracellular matter and unrenewable cell populations, including those comprising the brain. Their functions are incompatible with complete renewal. This makes the role of oxygen in aging not limited to being the source of reactive oxygen species. Oxygen had been indispensable for the advent of both accumulators of chemical damage and ability to recognize it. In a sense, it was not a problem for nature to develop aging in the course of evolution towards humans, for whom being aware of aging is a problem. Its satisfactory solution cannot be chemical, physical, pharmacological, or otherwise technical. It can only be mental.</p>","PeriodicalId":483,"journal":{"name":"Biochemistry (Moscow)","volume":"90 9","pages":"1188 - 1213"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ksenia A. Zaripova, Roman O. Bokov, Kristina A. Sharlo, Svetlana P. Belova, Tatiana L. Nemirovskaya
{"title":"IP3 Receptors Mediate Calcium and Anabolic Signaling Associated with Muscle Atrophy upon 3-Day Hind Limb Unloading in Rats","authors":"Ksenia A. Zaripova, Roman O. Bokov, Kristina A. Sharlo, Svetlana P. Belova, Tatiana L. Nemirovskaya","doi":"10.1134/S0006297925602497","DOIUrl":"10.1134/S0006297925602497","url":null,"abstract":"<p>Skeletal muscle unloading results in muscle atrophy associated with the upregulation of proteolytic genes and suppression of protein synthesis, often accompanied by altered calcium signaling. Here, we used the inositol trisphosphate receptor (IP3R) inhibitor aminoethoxydiphenyl borate (2-APB) to explore the hypothesis that these changes are mediated by IP3Rs. Male Wistar rats were divided into 4 groups: (i) control, (ii) control with daily injections of 2-APB, (iii) 3 days of hind limb suspension, (iv) 3 days of hind limb suspension with daily administration of 2-APB. At the end-point, soleus muscles from the animals were analyzed by Western blotting for the markers of calcium, anabolic, and catabolic signaling. The 3-day hind limb unloading resulted in a decreased muscle weight index, upregulation of the anabolic suppressor pThr56-eEF2, downregulation of anabolic signaling via the mTOR pathway and rRNA expression, as well as the increase in the content of nuclear pThr286-CaMKII (<i>p</i> < 0.05) and cytosolic calcineurin A. While 2-APB did not affect the mTOR-governed changes in anabolism and catabolism, it significantly attenuated alterations in the calcium-dependent targets, such as CaMKII, calcineurin, and eEF2. By contrast, proteolytic signaling (expression of MuRF1, atrogin-1, Ulk1, and ubiquitin mRNAs) after 3-day hind limb unloading was equally upregulated in the control and 2-APB-treated animals. These results suggest that IP3Rs are involved in the unloading-induced muscle atrophy by controlling the nuclear content of calcium; however, they are dispensable for reduced mTOR activity and altered metabolism.</p>","PeriodicalId":483,"journal":{"name":"Biochemistry (Moscow)","volume":"90 9","pages":"1214 - 1226"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Svetlana G. Roman, Andrey V. Slushchev, Victoria V. Nefedova, Aleksandr M. Matyushenko
{"title":"Effect of Non-Muscle Tropomyosin Isoforms Encoded by the TPM1 Gene on Cofilin-1 Activity toward Actin Filaments","authors":"Svetlana G. Roman, Andrey V. Slushchev, Victoria V. Nefedova, Aleksandr M. Matyushenko","doi":"10.1134/S0006297925601467","DOIUrl":"10.1134/S0006297925601467","url":null,"abstract":"<p>Actin cytoskeleton is a key participant in numerous cellular processes, including organelle transport, motility, contractility, exocytosis, and endocytosis. It also plays a critical role in pathological processes such as malignant cancer cell invasion. The actin-binding proteins, particularly tropomyosins (Tpm) and cofilins, are involved in actin cytoskeleton remodeling. For this study, we selected the least studied isoforms of Tpm expressed from the <i>TPM1</i> gene – Tpm1.7, Tpm1.8, and Tpm1.9 – as well as the more well-known Tpm1.1 and Tpm1.6. We investigated mutual influence of these Tpm isoforms and cofilin-1 (cof-1) on actin filament dynamics. Using co-sedimentation assays, we demonstrated that Tpm1.7, Tpm1.8, and Tpm1.9 significantly inhibit cof-1 binding to the F-actin surface. Viscometry was employed to assess depolymerizing and severing effects of cof-1 on actin filaments. Tpm1.1, Tpm1.8, and Tpm1.6 effectively prevented depolymerizing/severing action of cof-1, while the protective effect of Tpm1.7 and Tpm1.9 was less pronounced. The rhodamine-phalloidin displacement assay was used to analyze the cof-1-induced conformational changes in F-actin. All studied Tpm isoforms effectively prevented effects of cof-1 on actin filaments. Our findings indicate that the <i>TPM1</i> gene products generally exert an inhibitory effect on cof-1 activity in relation to actin filament polymerization/depolymerization dynamics. Such properties of Tpm isoforms could be important for formation of specific intracellular populations of actin filaments.</p>","PeriodicalId":483,"journal":{"name":"Biochemistry (Moscow)","volume":"90 9","pages":"1252 - 1263"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}