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Minaev SV, Grigorova AN, Vladimirova OV, Timofeev SI, Sirak AG, Vladimirov VI, Pogosyan AA, Zelenskaya MV. [Influence of connective tissue differentiation on scar tissue formation in children]. Khirurgiia (Mosk) 2021:72-77. [PMID: 33977701 DOI: 10.17116/hirurgia202105172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To study the immunohistochemical features of various scar tissues in children without connective tissue pathology and with undifferentiated connective tissue dysplasia syndrome. MATERIAL AND METHODS Tissue biopsy was performed in 217 children who underwent surgical treatment for various lesions, such as injuries, burns, as well as other procedures. There were 127 boys (58.5%) and 90 (41.5%) girls. The main group consisted of 98 (48.2%) children with scar tissue; group of UCTD syndrome - 65 (30.0%) children; control group - 43 (24.8%) patients without pathological scars. Histological examination of scar tissue and intact skin was carried out during primary or redo reconstructive surgery. Immunohistochemical study of antibodies against CD34, CD105, CD140b, PDGFs, COL types I, III and IV was performed. RESULTS The study showed a quantitative characteristic of expression of COL type I in hypertrophic scar with predominance in the main group (77.5±5.4%; p<0.05), and decrease in COL type IV. Keloid form was associated with predominance of granulation tissue in all layers of dermis and high levels of all types of collagen. In the group of UCTD, COL type III prevailed in all pathological forms of the scar. We determined quantitative indicators of expression of vascularization factors (CD34; CD105) and fibroblastic activity (CD140b; PDGFs). CONCLUSION Understanding the process of fibrinogenesis and analysis of stages of triggering mechanisms are essential for development of preventive algorithms. Individualized approach should be considered in the treatment. These studies are especially important in children with UCTD syndrome as high-risk group for pathological scarring. Thus, further research is required.
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Affiliation(s)
- S V Minaev
- Stavropol State Medical University, Stavropol, Russia
| | - A N Grigorova
- Stavropol State Medical University, Stavropol, Russia
| | | | - S I Timofeev
- Magadan Regional Children's Hospital, Magadan, Russia
| | - A G Sirak
- Stavropol State Medical University, Stavropol, Russia
| | - V I Vladimirov
- Pyatigorsk Interdistrict Oncology Dispensary, Pyatigorsk, Russia
| | - A A Pogosyan
- Stavropol State Medical University, Stavropol, Russia
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2
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Minaev SV, Vladimirova OV, Kirgizov IV, Akselrov MA, Razin MP, Ivchenko AA, Timofeev SI, Tarakanov VA, Barova NK, Obedin AN, Zelenskaya MV. [Multicenter study of the effectiveness of antiscar therapy in patients at different age periods]. Khirurgiia (Mosk) 2020:51-58. [PMID: 33030002 DOI: 10.17116/hirurgia202009151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Was to evaluate the effectiveness of anti-scar treatment with Contractubex gel in children and adults. MATERIAL AND METHODS A group of researchers based on clinical hospitals and university medical clinics carry out the multicenter study to evaluate the effectiveness of anti-scar treatment with Contractubex gel containing cepalin, allantoin and heparin, with its early appointment in groups of children from 12 to 18 years old and adults from 21 to 35 years old. The study included data from 216 patients. Patients of both age groups were initially divided into two: the main and control ones with an equal distribution according to the type of surgical intervention (hernia repair and appendectomy), age, gender, and anamnestic data. The dynamic observation was carried out using two rating scales - filled out by a doctor (Vancouver scale) and a patient (author's rating scale in the Scar Diary mobile application). RESULTS Based on the results of the analysis of the data obtained, a high efficiency of the use of Contractubex gel at the early stages of scar formation among patients of the main group in comparison with the control was revealed. By 90 days, the treatment result according to the Vancouver scale was 0,16±0,1 points in the main group and 0,39±0,2 points in the control group. At the same time, with a dynamic scale for assessing the cicatricial process, there was a significant (p<0.05) improvement in the main group (0,2±0,06 points) compared with the control group (0,6±0,17 points). In addition, was noticed the strong commitment to anti-scar treatment in pediatric patients. CONCLUSIONS The work confirms the undoubted need for anti-scar treatment in the early stages of scar formation after surgical interventions, which accelerates the psychophysical rehabilitation of patients after surgery and improves the quality of life.
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Affiliation(s)
- S V Minaev
- Stavropol State Medical University, Stavropol, Russia
| | | | - I V Kirgizov
- Russian Medical Academy of Continuous Professional Education, Moscow, Russia
| | | | - M P Razin
- Kirov State Medical University, Kirov, Russia
| | - A A Ivchenko
- Stavropol State Medical University, Stavropol, Russia
| | - S I Timofeev
- State Budgetary Institution of Healthcare Magadan Children Regional Hospital, Magadan, Russia
| | | | - N K Barova
- Kuban State Medical University, Krasnodar, Russia
| | - A N Obedin
- Stavropol State Medical University, Stavropol, Russia
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3
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Minaev SV, Ivchenko AA, Anisimov IN, Yakhyaeva LA, Ivchenko GS, Gerasimenko IN, Vladimirova OV. [Comparison of different methos of compression of scars with prolonged release plate]. Khirurgiia (Mosk) 2019:52-55. [PMID: 31120447 DOI: 10.17116/hirurgia201904152] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The purpose of the study was to compare the effectiveness of various compression techniques with a prolonged-action patch on postoperative scars. MATERIAL AND METHODS The study included 21 patients aged 3.6±1.7 years who had scars after surgery. The patients were divided into two groups: group No 1 (n=11), in which they applied longitudinal patch of prolonged-action Contractubex according to the standard technique; group No 2 (n=10) - transverse imposition of the patch on the postoperative scar (according to the author's method). RESULTS In 20 (95.5%) patients, good compliance was noted. By the 90th day after surgery, the width of the scar in the group No. 1 was significantly larger than in the group No. 2, being 2.5±0.15 and 2.0±0.1 (p<0.05). CONCLUSION Thus, the effectiveness of the proposed technique of transverse imposition of the patch Contractubex on the postoperative scar after surgical intervention was confirmed by a good cosmetic and functional result of scar formation.
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Affiliation(s)
- S V Minaev
- Stavropol State Medical University, Stavropol, Russia
| | - A A Ivchenko
- Stavropol State Medical University, Stavropol, Russia
| | - I N Anisimov
- Stavropol State Medical University, Stavropol, Russia
| | - L A Yakhyaeva
- Stavropol State Medical University, Stavropol, Russia
| | - G S Ivchenko
- Stavropol State Medical University, Stavropol, Russia
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4
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Negorev DG, Vladimirova OV, Kossenkov AV, Demarest RM, Showe MK, Rauscher FJ, Showe LC, Nikonova EV, Capobianco AJ. Retraction: Sp100 as a potent tumor suppressor: accelerated senescence and rapid malignant transformation of human fibroblasts through modulation of an embryonic stem cell program. Cancer Res 2013; 73:4960-1. [PMID: 23907639 DOI: 10.1158/0008-5472.can-13-1715] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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5
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Negorev DG, Vladimirova OV, Kossenkov AV, Nikonova EV, Demarest RM, Capobianco AJ, Showe MK, Rauscher FJ, Showe LC, Maul GG. Sp100 as a potent tumor suppressor: accelerated senescence and rapid malignant transformation of human fibroblasts through modulation of an embryonic stem cell program. Cancer Res 2010; 70:9991-10001. [PMID: 21118961 PMCID: PMC3059726 DOI: 10.1158/0008-5472.can-10-1483] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Identifying the functions of proteins, which associate with specific subnuclear structures, is critical to understanding eukaryotic nuclear dynamics. Sp100 is a prototypical protein of ND10/PML nuclear bodies, which colocalizes with Daxx and the proto-oncogenic PML. Sp100 isoforms contain SAND, PHD, Bromo, and HMG domains and are highly sumoylated, all characteristics suggestive of a role in chromatin-mediated gene regulation. A role for Sp100 in oncogenesis has not been defined previously. Using selective Sp100 isoform-knockdown approaches, we show that normal human diploid fibroblasts with reduced Sp100 levels rapidly senesce. Subsequently, small rapidly dividing Sp100 minus cells emerge from the senescing fibroblasts and are found to be highly tumorigenic in nude mice. The derivation of these tumorigenic cells from the parental fibroblasts is confirmed by microsatellite analysis. The small rapidly dividing Sp100 minus cells now also lack ND10/PML bodies, and exhibit genomic instability and p53 cytoplasmic sequestration. They have also activated MYC, RAS, and TERT pathways and express mesenchymal to epithelial transdifferentiation (MET) markers. Reintroduction of expression of only the Sp100A isoform is sufficient to maintain senescence and to inhibit emergence of the highly tumorigenic cells. Global transcriptome studies, quantitative PCR, and protein studies, as well as immunolocalization studies during the course of the transformation, reveal that a transient expression of stem cell markers precedes the malignant transformation. These results identify a role for Sp100 as a tumor suppressor in addition to its role in maintaining ND10/PML bodies and in the epigenetic regulation of gene expression.
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MESH Headings
- Animals
- Antigens, Nuclear/genetics
- Antigens, Nuclear/metabolism
- Autoantigens/genetics
- Autoantigens/metabolism
- Blotting, Western
- Cell Transformation, Neoplastic/genetics
- Cells, Cultured
- Cellular Senescence/genetics
- Embryonic Stem Cells/metabolism
- Epithelial-Mesenchymal Transition/genetics
- Fibroblasts/cytology
- Fibroblasts/metabolism
- Gene Expression Profiling
- HEK293 Cells
- Humans
- Male
- Mice
- Mice, Nude
- Neoplasms, Experimental/genetics
- Neoplasms, Experimental/metabolism
- Neoplasms, Experimental/pathology
- Nuclear Proteins/metabolism
- Oligonucleotide Array Sequence Analysis
- Promyelocytic Leukemia Protein
- Proto-Oncogene Proteins c-myc/metabolism
- RNA Interference
- Reverse Transcriptase Polymerase Chain Reaction
- Transcription Factors/metabolism
- Transplantation, Heterologous
- Tumor Suppressor Proteins/genetics
- Tumor Suppressor Proteins/metabolism
- ras Proteins/metabolism
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Affiliation(s)
| | | | | | | | | | | | - Michael K. Showe
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104
| | | | - Louise C. Showe
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104
| | - Gerd G. Maul
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104
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6
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Negorev DG, Vladimirova OV, Maul GG. Differential functions of interferon-upregulated Sp100 isoforms: herpes simplex virus type 1 promoter-based immediate-early gene suppression and PML protection from ICP0-mediated degradation. J Virol 2009; 83:5168-80. [PMID: 19279115 PMCID: PMC2682089 DOI: 10.1128/jvi.02083-08] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Accepted: 02/27/2009] [Indexed: 12/26/2022] Open
Abstract
Cells have intrinsic defenses against virus infection, acting before the innate or the adaptive immune response. Preexisting antiviral proteins such as PML, Daxx, and Sp100 are stored in specific nuclear domains (ND10). In herpes simplex virus type 1 (HSV-1), the immediate-early protein ICP0 serves as a counterdefense through degradation of the detrimental protein PML. We asked whether interferon (IFN)-upregulated Sp100 is similarly antagonized by ICP0 in normal human fibroblasts by using a selective-knockdown approach. We find that of the four Sp100 isoforms, the three containing a SAND domain block the transcription of HSV-1 proteins ICP0 and ICP4 at the promoter level and that IFN changes the differential splicing of the Sp100 transcript in favor of the inhibitor Sp100C. At the protein level, ICP0 activity does not lead to the hydrolysis of any of the Sp100 isoforms. The SAND domain-containing isoforms are not general inhibitors of viral promoters, as the activity of the major immediate-early cytomegalovirus promoter is not diminished, whereas the long terminal repeat of a retrovirus, like the ICP0 promoter, is strongly inhibited. Since we could not find a specific promoter region in the ICP0 gene that responds to the SAND domain-containing isoforms, we questioned whether Sp100 could act through other antiviral proteins such as PML. We find that all four Sp100 isoforms stabilize ND10 and protect PML from ICP0-based hydrolysis. Loss of either all PML isoforms or all Sp100 isoforms reduces the opposite constituent ND10 protein, suggesting that various interdependent mechanisms of ND10-based proteins inhibit virus infection at the immediate-early level.
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Affiliation(s)
- Dmitri G Negorev
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
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7
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Negorev DG, Vladimirova OV, Ivanov A, Rauscher F, Maul GG. Differential role of Sp100 isoforms in interferon-mediated repression of herpes simplex virus type 1 immediate-early protein expression. J Virol 2006; 80:8019-29. [PMID: 16873258 PMCID: PMC1563809 DOI: 10.1128/jvi.02164-05] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2005] [Accepted: 05/15/2006] [Indexed: 01/12/2023] Open
Abstract
Nuclear domains called ND10 or PML nuclear bodies contain interferon (IFN)-upregulated proteins like PML and Sp100. Paradoxically, herpes simplex virus 1 (HSV-1) begins its transcriptional cascade at aggregates of ND10-associated proteins, which in turn are destroyed by the HSV-1 immediate-early protein ICP0. While PML is essential in the formation of ND10, the function of Sp100 in the cells' defense against viral infection is unknown. In this study we investigated the potential antiviral effect of IFN-beta-induced Sp100. We found that IFN-beta treatment leads to a differential accumulation of four Sp100 isoforms in different cell lines. Using an HEK293 cell line derivative, 293-S, producing no detectable amounts of Sp100 even after IFN exposure, we analyzed individual Sp100 isoforms for their effect on HSV-1 infection. Sp100 isoforms B, C, and HMG, but not Sp100A, suppressed ICP0 and ICP4 early after infection. Isoforms B, C, and HMG suppressed expression from the ICP0 promoter in transient transfection, whereas Sp100A enhanced expression. Moreover, Sp100A localized in ND10, whereas the repressive isoforms were either dispersed within the nucleus or, at unphysiologically higher expression levels, formed new aggregates. The repressive activity was dependent on an intact SAND domain, since Sp100B bearing a W655Q mutation in the SAND domain lost this repressive activity and accumulated in ND10. Using RNA interference to knock down the repressive Sp100 isoforms B, C, and HMG, we find that they are an essential part of the IFN-beta-mediated suppression of ICP0 expression. These data suggest that repression by the Sp100 isoforms B, C, and HMG takes place outside of ND10 and raise the possibility that viral genomes at Sp100A accumulations are more likely to start their transcription program because of a more permissive local environment.
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Affiliation(s)
- Dmitri G Negorev
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19103, USA
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8
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Ishov AM, Vladimirova OV, Maul GG. Heterochromatin and ND10 are cell-cycle regulated and phosphorylation-dependent alternate nuclear sites of the transcription repressor Daxx and SWI/SNF protein ATRX. J Cell Sci 2004; 117:3807-20. [PMID: 15252119 DOI: 10.1242/jcs.01230] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Placing regulatory proteins into different multiprotein complexes should modify key cellular processes. Here, we show that the transcription repressor Daxx and the SWI/SNF protein ATRX are both associated with two intranuclear domains: ND10/PML bodies and heterochromatin. The accumulation of ATRX at nuclear domain 10 (ND10) was mediated by its interaction with the N-terminus of Daxx. Binding of this complex to ND10 was facilitated by the interaction of the Daxx C-terminus with SUMOylated promyelocytic leukemia protein (PML). Although ATRX was present at heterochromatin during the entire cell cycle, Daxx was actively recruited to this domain at the end of S-phase. The FACT-complex member structure-specific recognition protein 1 (SSRP1) accumulated at heterochromatin simultaneously with Daxx and accumulation of both proteins depended on ATRX phosphorylation. Both Daxx and SSRP1 were released from heterochromatin early in G(2) phase and Daxx was recruited back to ND10, indicating that both proteins localize to heterochromatin during a very short temporal window of the cell cycle. ATRX seems to assemble a repression multiprotein complex including Daxx and SSRP1 at heterochromatin during a specific stage of the cell cycle, whereas Daxx functions as an adapter for ATRX accumulation at ND10. A potential functional consequence of Daxx accumulation at heterochromatin was found in the S- to G(2)-phase transition. In Daxx(-/-) cells, S-phase was accelerated and the propensity to form double nuclei was increased, functional changes that could be rescued by Daxx reconstitution and that might be the basis for the developmental problems observed in Daxx knockout animals.
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Affiliation(s)
- Alexander M Ishov
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
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9
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Ishov AM, Vladimirova OV, Maul GG. Daxx-mediated accumulation of human cytomegalovirus tegument protein pp71 at ND10 facilitates initiation of viral infection at these nuclear domains. J Virol 2002; 76:7705-12. [PMID: 12097584 PMCID: PMC136388 DOI: 10.1128/jvi.76.15.7705-7712.2002] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Human cytomegalovirus (HCMV) starts immediate-early transcription at nuclear domains 10 (ND10), forming a highly dynamic immediate transcript environment at this nuclear site. The reason for this spatial correlation remains enigmatic, and the mechanism for induction of transcription at ND10 is unknown. We investigated whether tegument-based transactivators are involved in the specific intranuclear location of HCMV. Here, we demonstrate that the HCMV transactivator tegument protein pp71 accumulates at ND10 before the production of immediate-early proteins. Intracellular trafficking of pp71 is facilitated through binding to a coiled-coil region of Daxx. The C-terminal domain of Daxx then interacts with SUMO-modified PML, resulting in the deposition of pp71 at ND10. In Daxx-deficient cells, pp71 does not accumulate at ND10, proving in vivo the necessity of Daxx for pp71 deposition. Also, HCMV forms immediate transcript environments at sites other than ND10 in Daxx-deficient cells, and so does the HCMV pp71 knockout mutant UL82(-/-) in normal cells. This result strongly suggests that pp71 and Daxx are essential for HCMV transcription at ND10. Lack of Daxx had the effect of reducing the infection rate. We conclude that the tegument transactivator pp71 facilitates viral genome deposition and transcription at ND10, possibly priming HCMV for more efficient productive infection.
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10
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Ishov AM, Sotnikov AG, Negorev D, Vladimirova OV, Neff N, Kamitani T, Yeh ET, Strauss JF, Maul GG. PML is critical for ND10 formation and recruits the PML-interacting protein daxx to this nuclear structure when modified by SUMO-1. J Cell Biol 1999; 147:221-34. [PMID: 10525530 PMCID: PMC2174231 DOI: 10.1083/jcb.147.2.221] [Citation(s) in RCA: 650] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/1999] [Accepted: 09/10/1999] [Indexed: 12/15/2022] Open
Abstract
Nuclear domain 10 (ND10), also referred to as nuclear bodies, are discrete interchromosomal accumulations of several proteins including promyelocytic leukemia protein (PML) and Sp100. In this study, we investigated the mechanism of ND10 assembly by identifying proteins that are essential for this process using cells lines that lack individual ND10-associated proteins. We identified the adapter protein Daxx and BML, the RecQ helicase missing in Bloom syndrome, as new ND10-associated proteins. PML, but not BLM or Sp100, was found to be responsible for the proper localization of all other ND10-associated proteins since they are dispersed in PML-/- cells. Introducing PML into this cell line by transient expression or fusion with PML-producing cells recruited ND10-associated proteins into de novo formed ND10 attesting to PMLs essential nature in ND10 formation. In the absence of PML, Daxx is highly enriched in condensed chromatin. Its recruitment to ND10 from condensed chromatin requires a small ubiquitin-related modifier (SUMO-1) modification of PML and reflects the interaction between the COOH-terminal domain of Daxx and PML. The segregation of Daxx from condensed chromatin in the absence of PML to ND10 by increased accumulation of SUMO-1-modified PML suggests the presence of a variable equilibrium between these two nuclear sites. Our findings identify the basic requirements for ND10 formation and suggest a dynamic mechanism for protein recruitment to these nuclear domains controlled by the SUMO-1 modification state of PML.
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Affiliation(s)
| | | | | | | | - Norma Neff
- Kimball Research Institute, New York, New York 10021
| | - Tetsu Kamitani
- Division of Molecular Medicine, University of Texas Health Center, Houston, Texas 77030
| | - Edward T.H. Yeh
- Division of Molecular Medicine, University of Texas Health Center, Houston, Texas 77030
| | - Jerome F. Strauss
- Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Gerd G. Maul
- The Wistar Institute, Philadelphia, Pennsylvania 19104
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11
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Anarbaev RO, Vladimirova OV, Lavrik OI. The interaction of synthetic templates with eukaryotic DNA primase. Eur J Biochem 1995; 228:60-7. [PMID: 7883012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The template interaction of calf thymus and human placenta DNA primases has been investigated. Using oligothymidylates, we showed that a template consisting of ten monomeric units was the critical size for interaction with the enzyme. The hydrophobic effect is likely to be a major factor determining template recognition by the DNA primase. The correlation between the template affinity with the enzyme and the octanol-water hydrophobic scale confirms this suggestion. In addition, the electrostatic interaction between the phosphate group of the template and side chains on the enzyme probably increases template affinity. Using methylated poly(dA), we found that the first nucleotide base of the primer should be more hydrophobic than the corresponding nucleotide base of the template. A model for the mechanism of action of DNA primase is suggested on the basis of data presented in this study and previous findings. According to this model, (a) DNA primase binds ten nucleotides of the template; (b) the synthesis of primer up to the formation of a decamer occurs processively and competes with template binding of the enzyme; (c) the conditions under which the nucleotides are incorporated into the RNA product change during the extension of the primer, and these changes are responsible for switching from primase to polymerase activity. The template specificity of DNA primase is likely to play an important role in the initiation and regulation of DNA replication.
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Affiliation(s)
- R O Anarbaev
- Novosibirsk Institute of Bioorganic Chemistry, Russia
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12
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13
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Podust VN, Vladimirova OV, Manakova EN, Lavrik OI. Eukaryotic DNA primase appears to act as oligomer in DNA-polymerase-alpha--primase complex. Eur J Biochem 1992; 206:7-13. [PMID: 1587285 DOI: 10.1111/j.1432-1033.1992.tb16895.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Human placenta and calf thymus DNA-polymerase-alpha-primases were analyzed using native gradient-polyacrylamide-gel electrophoresis followed by overlay assays of polymerase and primase activities. The human enzyme contained three catalytically active native forms of 330, 440 and 560 kDa and the bovine enzyme five forms of 330, 440, 500, 590 and 660 kDa. Of the various DNA polymerase forms, only the largest (560 kDa for human DNA polymerase and 590 kDa and 660 kDa for bovine DNA polymerase) contained primase activity. Titration of human DNA-polymerase-alpha-primase with DNA-polymerase-free primase caused the conversion of the 440-kDa to the 560-kDa form. The data favour the idea that primase binds to DNA polymerase alpha as an oligomer of 3 primases/polymerase core. In addition, the ability of primase to utilize oligoriboadenylates containing (prA)n or pp(prA)n was investigated. The primase elongated pp(prA)2-7 up to nanoadenylates or decaadenylates, but did not add 9 or 10 mononucleotides to a preexistent primer. In contrast to pp(prA)n less than 10, (prA)n less than 10 were rather poor primers for the primase. Both pp(prA)8,9 and (prA)n greater than 10 were elongated by primase, producing characteristic multimeric oligonucleotides. The possible connection of the structure of the DNA-polymerase-alpha-primase complex with the catalytical properties of primase is discussed.
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Affiliation(s)
- V N Podust
- Novosibirsk Institute of Bioorganic Chemistry, Russia
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14
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Abstract
Calf thymus DNA polymerase alpha-primase, human placenta DNA polymerase alpha-primase and human placenta DNA primase synthesized oligoriboadenylates of a preferred length of 2-10 nucleotides and multimeric oligoribonucleotides of a modal length of about 10 monomers on a poly(dT) template. The dimer and trimer were the prevalent products of the polymerization reaction. However, only the oligonucleotides from heptamers to decamers were elongated efficiently by DNA polymerase alpha.
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Affiliation(s)
- V N Podust
- Institute of Bioorganic Chemistry, Siberian Division of the USSR Academy of Sciences, Novosibirsk
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15
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Vladimirova OV. [Phosphatase activity of soil actinomycetes]. Mikrobiol Zh 1968; 30:16-21. [PMID: 4308583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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