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Biophysical Journal Jun 2021DNA looping plays an important role in cells in both regulating and protecting the genome. Often, studies of looping focus on looping by prokaryotic transcription...
DNA looping plays an important role in cells in both regulating and protecting the genome. Often, studies of looping focus on looping by prokaryotic transcription factors like lac repressor or by structural maintenance of chromosomes proteins such as condensin. Here, however, we are interested in a different looping method whereby condensing agents (charge ≥+3) such as protamine proteins neutralize the DNA, causing it to form loops and toroids. We considered two previously proposed mechanisms for DNA looping by protamine. In the first mechanism, protamine stabilizes spontaneous DNA fluctuations, forming randomly distributed loops along the DNA. In the second mechanism, protamine binds and bends the DNA to form a loop, creating a distribution of loops that is biased by protamine binding. To differentiate between these mechanisms, we imaged both spontaneous and protamine-induced loops on short-length (≤1 μm) DNA fragments using atomic force microscopy. We then compared the spatial distribution of the loops to several model distributions. A random looping model, which describes the mechanism of spontaneous DNA folding, fit the distribution of spontaneous loops, but it did not fit the distribution of protamine-induced loops. Specifically, it failed to predict a peak in the spatial distribution of loops at an intermediate location along the DNA. An electrostatic multibinding model, which was created to mimic the bind-and-bend mechanism of protamine, was a better fit of the distribution of protamine-induced loops. In this model, multiple protamines bind to the DNA electrostatically within a particular region along the DNA to coordinate the formation of a loop. We speculate that these findings will impact our understanding of protamine's in vivo role for looping DNA into toroids and the mechanism of DNA condensation by condensing agents more broadly.
Topics: Chromosomes; DNA; Lac Repressors; Nucleic Acid Conformation; Protamines
PubMed: 34023297
DOI: 10.1016/j.bpj.2021.04.022 -
Nature Communications May 2023Genetic studies elucidate a link between testis-specific serine/threonine kinases (TSSKs) and male infertility in mammals, but the underlying mechanisms are unclear....
Genetic studies elucidate a link between testis-specific serine/threonine kinases (TSSKs) and male infertility in mammals, but the underlying mechanisms are unclear. Here, we identify a TSSK homolog in Drosophila, CG14305 (termed dTSSK), whose mutation impairs the histone-to-protamine transition during spermiogenesis and causes multiple phenotypic defects in nuclear shaping, DNA condensation, and flagellar organization in spermatids. Genetic analysis demonstrates that kinase catalytic activity of dTSSK, which is functionally conserved with human TSSKs, is essential for male fertility. Phosphoproteomics identify 828 phosphopeptides/449 proteins as potential substrates of dTSSK enriched primarily in microtubule-based processes, flagellar organization and mobility, and spermatid differentiation and development, suggesting that dTSSK phosphorylates various proteins to orchestrate postmeiotic spermiogenesis. Among them, the two substrates, protamine-like protein Mst77F/Ser and transition protein Mst33A/Ser, are biochemically validated to be phosphorylated by dTSSK in vitro, and are genetically demonstrated to be involved in spermiogenesis in vivo. Collectively, our findings demonstrate that broad phosphorylation mediated by TSSKs plays an indispensable role in spermiogenesis.
Topics: Animals; Male; Humans; Protein Serine-Threonine Kinases; Testis; Phosphorylation; Spermatogenesis; Histones; Drosophila; Protamines; Fertility; Serine; Threonine; Mammals
PubMed: 37149634
DOI: 10.1038/s41467-023-38357-0 -
Nutrients Jul 2021Dietary protamine can ameliorate hyperlipidemia; however, the protamine-derived active peptide and its hypolipidemic mechanism of action are unclear. Here, we report the...
Dietary protamine can ameliorate hyperlipidemia; however, the protamine-derived active peptide and its hypolipidemic mechanism of action are unclear. Here, we report the discovery of a novel anti-obesity and hypocholesterolemic peptide, RPR (Arg-Pro-Arg), derived from protamine in mice fed a high-fat diet for 50 days. Serum cholesterol levels were significantly lower in the protamine and RPR groups than in the control group. White adipose tissue weight was significantly decreased in the protamine and RPR groups. The fecal excretion of cholesterol and bile acid was significantly higher in the protamine and RPR groups than in the control group. We also observed a significant decrease in the expression of hepatic SCD1, SREBP1, and adipocyte FAS mRNA, and significantly increased expression of hepatic PPARα and adipocyte PPARγ1 mRNA in the protamine group. These findings demonstrate that the anti-obesity effects of protamine are linked to the upregulation of adipocyte PPARγ1 and hepatic PPARα and the downregulation of hepatic SCD1 via SREBP1 and adipocyte FAS. RPR derived from protamine has a crucial role in the anti-obesity action of protamine by evaluating the effective dose of adipose tissue weight loss.
Topics: Adipose Tissue, White; Adiposity; Animals; Anti-Obesity Agents; Anticholesteremic Agents; Biomarkers; Cholesterol; Diet, High-Fat; Disease Models, Animal; Fatty Acid Synthase, Type I; Liver; Male; Mice, Inbred C57BL; Obesity; Oligopeptides; PPAR alpha; PPAR gamma; Protamines; Stearoyl-CoA Desaturase; Sterol Regulatory Element Binding Protein 1; Weight Loss; Mice
PubMed: 34444660
DOI: 10.3390/nu13082501 -
Analytical Sciences : the International... Sep 2023This paper describes a sensitive method for determining protamine and heparin by utilizing a glucose oxidase enzymatic reaction. Polycationic protamine significantly...
This paper describes a sensitive method for determining protamine and heparin by utilizing a glucose oxidase enzymatic reaction. Polycationic protamine significantly promoted the enzymatic reaction rate with [Fe(CN)], so that the increase could be used to determine protamine. The promotion effect was stoichiometrically decreased by the addition of polyanionic heparin through the polyion complex formation with protamine, so that the enzymatic reaction also allowed for the determination of heparin. We thus applied the proposed method to blood plasma containing heparin and found that heparin did not stoichiometrically form a polyion complex with protamine, likely due to strong interactions between heparin and some components of the plasma. The proposed method allowed for the detection of free protamine (and/or weakly binding protamine with heparin) existing in the condition that protamine did not neutralize all of the heparin in the plasma. The method also permitted for the estimation of heparin concentrations using calibration curves. Thus, the proposed method would help reduce the risks of protamine overdose in heparin neutralization and would be a helpful tool in clinical practices that use heparin and protamine.
Topics: Heparin; Protamines; Glucose Oxidase
PubMed: 37243969
DOI: 10.1007/s44211-023-00373-x -
Frontiers in Genetics 2020The genome of eukaryotes is highly organized within the cell nucleus, this organization elicits gene regulation and favors other mechanisms like cell memory throughout... (Review)
Review
The genome of eukaryotes is highly organized within the cell nucleus, this organization elicits gene regulation and favors other mechanisms like cell memory throughout histones and their post-translational modifications. In highly specialized cells, like sperm, the genome is mostly organized by protamines, yet a significant portion of it remains organized by histones. This protamine-histone-DNA organization, known as sperm epigenome, is established during spermiogenesis. Specific histones and their post-translational modifications are retained at specific genomic sites and during embryo development these sites recapitulate their histone profile that harbored in the sperm nucleus. It is known that histones are the conduit of epigenetic memory from cell to cell, hence histones in the sperm epigenome may have a role in transmitting epigenetic memory from the sperm to the embryo. However, the exact function and mechanism of histone retention remains elusive. During spermatogenesis, most of the histones that organize the genome are replaced by protamines and their retention at specific regions may be deeply intertwined with the eviction and replacement mechanism. In this review we will cover some relevant aspects of histone replacement that in turn may help us to contextualize histone retention. In the end, we focus on the architectonical protein CTCF that is, so far, the only factor that has been directly linked to the histone retention process.
PubMed: 32765595
DOI: 10.3389/fgene.2020.00780 -
BMC Cardiovascular Disorders May 2022Compared to simple percutaneous coronary intervention (PCI), complex PCI is associated with higher bleeding and thrombotic risk. No previous study has evaluated the use...
BACKGROUND
Compared to simple percutaneous coronary intervention (PCI), complex PCI is associated with higher bleeding and thrombotic risk. No previous study has evaluated the use of protamine after PCI with contemporary technologies. This study aimed to evaluate the safety and efficacy of manual compression with and without protamine after transfemoral complex PCI.
METHODS
We retrospectively analyzed 160 patients (protamine group, n = 92; non-protamine group, n = 68) who underwent complex PCI via the femoral artery. The primary outcome was a composite of in-hospital death, myocardial infarction, stent thrombosis, stroke/systemic embolism, bleeding requiring blood transfusion, and vascular access complications.
RESULTS
The primary outcome was significantly lower in the protamine group than in the non-protamine group (4.3% vs. 17.6%; p = 0.006). This was driven mainly by the lower incidences of hematoma in the protamine group (3.3% vs. 13.2%, p = 0.020). Furthermore, the protamine group had a significantly shorter hospital stay than the non-protamine group (4.8 ± 3.7 days vs. 8.4 ± 8.3 days, p = 0.001). While > 90% of the patients had acute coronary syndrome, there were no incidences of myocardial infarction or stent thrombosis in either group.
CONCLUSIONS
Among patients who underwent complex PCI via transfemoral access, immediate protamine administration was associated with a significantly lower rate of vascular access complications, especially hematoma, and shorter hospital stay than no protamine administration.
Topics: Anticoagulants; Hematoma; Hemorrhage; Heparin; Hospital Mortality; Humans; Myocardial Infarction; Percutaneous Coronary Intervention; Protamines; Retrospective Studies; Thrombosis; Treatment Outcome
PubMed: 35538419
DOI: 10.1186/s12872-022-02650-5 -
Frontiers in Genetics 2019Spermiogenesis is a complex cellular differentiation process that the germ cells undergo a distinct morphological change, and the protamines replace the core histones to... (Review)
Review
Spermiogenesis is a complex cellular differentiation process that the germ cells undergo a distinct morphological change, and the protamines replace the core histones to facilitate chromatin compaction in the sperm head. Recent studies show the essential roles of epigenetic events during the histone-to-protamine transition. Defects in either the replacement or the modification of histones might cause male infertility with azoospermia, oligospermia or teratozoospermia. Here, we summarize recent advances in our knowledge of how epigenetic regulators, such as histone variants, histone modification and their related chromatin remodelers, facilitate the histone-to-protamine transition during spermiogenesis. Understanding the molecular mechanism underlying the modification and replacement of histones during spermiogenesis will enable the identification of epigenetic biomarkers of male infertility, and shed light on potential therapies for these patients in the future.
PubMed: 31649732
DOI: 10.3389/fgene.2019.00962 -
Annals of Cardiac Anaesthesia 2021Protamine is routinely administered to neutralize the anticlotting effects of heparin, traditionally at a dose of 1 mg for every 100 IU of heparin-a 1:1 ratio protamine... (Observational Study)
Observational Study
CONTEXT
Protamine is routinely administered to neutralize the anticlotting effects of heparin, traditionally at a dose of 1 mg for every 100 IU of heparin-a 1:1 ratio protamine sparing effects-but this is based more on experience and practice than literature evidence. The use of Hemostasis Management System (HMS) allows an individualized heparin and protamine titration. This usually results in a decreased protamine dose, thus limiting its side effects, including paradox anticoagulation.
AIMS
This study aims to assess how the use of HMS allows to reduction of protamine administration while restoring the basal activated clotting time (ACT) at the end of cardiac surgery.
SETTINGS AND DESIGN
A retrospective observational study in a tertiary care university hospital.
SUBJECTS AND METHODS
We analyzed data from 42 consecutive patients undergoing cardiopulmonary bypass (CPB) for cardiac surgery. For all patients HMS tests were performed before and after CPB, to determine how much heparin was needed to reach target ACT, and how much protamine was needed to reverse it.
RESULTS
At the end of cardiopulmonary bypass, 2.2 ± 0.5 mg/kg of protamine was sufficient to reverse heparin effects. The protamine-to-heparin ratio was 0.56:1 over heparin total dose (a 44% reduction) and 0.84:1 over heparin initial dose (a 16% reduction).
CONCLUSION
A lower dose of protamine was sufficient to revert heparin effects after cardiopulmonary bypass. While larger studies are needed to confirm these findings and detect differences in clinically relevant outcomes, the administration of a lower protamine dose is endorsed by current guidelines and may help to avoid the detrimental effects of protamine overdose, including paradox bleeding.
Topics: Anticoagulants; Cardiac Surgical Procedures; Cardiopulmonary Bypass; Heparin; Heparin Antagonists; Humans; Protamines; Whole Blood Coagulation Time
PubMed: 33884973
DOI: 10.4103/aca.ACA_26_19 -
American Journal of Clinical and... 2021Sperm selection without - or with a low level of - protamine deficiency and DNA fragmentation is a remarkable indicator to increase the success rate of ICSI outcomes....
OBJECTIVE
Sperm selection without - or with a low level of - protamine deficiency and DNA fragmentation is a remarkable indicator to increase the success rate of ICSI outcomes. The aim of this study was to compare sperm selection methods in the elimination of sperm with protamine deficiency and DNA fragmentation and their effects on ICSI Outcomes in oligoteratzoospermia patients.
METHODS
Semen samples were obtained from oligoteratozoospermia patients undergoing ICSI. Sperm selection was conducted using Zona Pellucida (ZP) binding, Hyaluronic Acid (HA) binding, and conventional PVP methods. SCD assay and CMA3 staining were used for the detection of sperm protamine deficiency and DNA fragmentation. Good quality of the embryo, blastocyst formation, chemical, and clinical pregnancy rates among studied groups was evaluated and compared.
RESULTS
Our results indicated the percentage of sperm DNA fragmentation and protamine deficiency were lower significantly in the HA- and ZP-bound sperm. Although no significant differences were observed in the fertilization rate among studied methods, good quality of cleavage embryo rates were increased using ZP and HA methods versus the conventional PVP method. However, there were no significant differences in cleavage and embryo quality between the HA compared to the ZP method. Blastocyst formation, chemical and clinical pregnancy rates increased in the HA method.
CONCLUSIONS
Overall, the HA method for sperm selection due to high sensitivity in selecting sperm with a low level of DNA fragmentation and protamine deficiency is a very useful method to increase the success rate of ICSI outcomes in oligoteratozoospermia patients.
PubMed: 34079849
DOI: No ID Found -
Nature Nov 2022Sperm chromatin is typically transformed by protamines into a compact and transcriptionally inactive state. Sperm cells of flowering plants lack protamines, yet they...
Sperm chromatin is typically transformed by protamines into a compact and transcriptionally inactive state. Sperm cells of flowering plants lack protamines, yet they have small, transcriptionally active nuclei with chromatin condensed through an unknown mechanism. Here we show that a histone variant, H2B.8, mediates sperm chromatin and nuclear condensation in Arabidopsis thaliana. Loss of H2B.8 causes enlarged sperm nuclei with dispersed chromatin, whereas ectopic expression in somatic cells produces smaller nuclei with aggregated chromatin. This result demonstrates that H2B.8 is sufficient for chromatin condensation. H2B.8 aggregates transcriptionally inactive AT-rich chromatin into phase-separated condensates, which facilitates nuclear compaction without reducing transcription. Reciprocal crosses show that mutation of h2b.8 reduces male transmission, which suggests that H2B.8-mediated sperm compaction is important for fertility. Altogether, our results reveal a new mechanism of nuclear compaction through global aggregation of unexpressed chromatin. We propose that H2B.8 is an evolutionary innovation of flowering plants that achieves nuclear condensation compatible with active transcription.
Topics: Arabidopsis; Chromatin; Histones; Protamines; Pollen; Gene Expression Regulation, Plant; AT Rich Sequence; Cell Nucleus; Mutation; Cell Nucleus Size; Phase Transition; Cell Size; Transcription, Genetic
PubMed: 36323776
DOI: 10.1038/s41586-022-05386-6