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You searched for subject:(Branch migration). Showing records 1 – 2 of 2 total matches.

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The Ohio State University

1. Soukup, Randal J. The roles of hMSH4-hMSH5 and hMLH1-hMLH3 in meiotic double strand break repair.

Degree: PhD, Molecular, Cellular and Developmental Biology, 2016, The Ohio State University

The DNA double strand break is a highly cytotoxic DNA lesion. Mouse and human mitotically dividing cells experience ~10 double strand breaks (DSBs) per day that are often repaired through non-homologous end joining and result in the accumulation of short deletions. However, in prophase I of meiosis, ~400 double strand breaks are introduced into primary mouse spermatocytes by the endonuclease SPO11. The cell undergoes a cell-wide DSB repair response which functions to repair each break, and in doing so, pair homologous chromosomes for segregation at the outset of meiosis I. This process generates genetic crossovers between the homologous chromosomes, which are required for accurate chromosome segregation and are also the basis for the reshuffling of genes between maternal and paternal chromosomes. At the center of this DNA repair process is the Holliday Junction, which physically links homologous chromosomes and whose resolution defines the outcome to a genetic crossover or gene conversion event. A number of proteins involved in mitotic DSB repair are also involved with the meiotic process. However, MSH4-MSH5 and MLH1-MLH3 proteins appear to have unique roles in establishing homologous chromosome pairing and segregation during meiotic DSB repair, but do not play any role in mitotic DSB repair.Here we used purified hMSH4-hMSH5 to conduct a series of binding experiments with numerous Holliday Junction constructs. We demonstrate binding of mobile, as well as immobile, Holliday Junctions by hMSH4-hMSH5, and the ability to retain ATP bound hydrolysis-independent sliding clamps on a blocked-end mobile Holliday Junction. In addition, we show that the binding of hMSH4-hMSH5 does not appear to distinguish between the stacked-X or planar conformations of the Holliday Junction. The rate of bulk branch migration by an assembled Holliday Junction did not appear to be affected by the addition of hMSH4-hMSH5. The development of a single molecule approach is reported and will ultimately be used to determine whether the protein transiently or kinetically influences branch migration of individual Holliday Junctions.With no protein currently identified that functions to maintain homologous chromosome pairing through segregation or perform the required Holliday Junction resolution prior to segregation, we partially purified and examined the hMLH1-hMLH3 heterodimer that has been shown to be associated with the development of homologous chromosome linkages. Our preparation of hMLH1-hMLH3 does not appear to display any endonuclease activity or stable complex formation with hMSH4-hMSH5. As has been previously reported we do observe an aggregate that appears to form between hMLH1-hMLH3 and Holliday Junctions at very low ionic strengths. Further hMLH1-hMLH3 purification is required for more complex studies to be performed. Advisors/Committee Members: Fishel, Richard (Advisor).

Subjects/Keywords: Molecular Biology; Biochemistry; Biophysics; hMSH4-hMSH5; Double Strand Break Repair; Holliday Junction; Branch Migration; Biophysics; Molecular Biology

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APA (6th Edition):

Soukup, R. J. (2016). The roles of hMSH4-hMSH5 and hMLH1-hMLH3 in meiotic double strand break repair. (Doctoral Dissertation). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1480641841905001

Chicago Manual of Style (16th Edition):

Soukup, Randal J. “The roles of hMSH4-hMSH5 and hMLH1-hMLH3 in meiotic double strand break repair.” 2016. Doctoral Dissertation, The Ohio State University. Accessed November 27, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1480641841905001.

MLA Handbook (7th Edition):

Soukup, Randal J. “The roles of hMSH4-hMSH5 and hMLH1-hMLH3 in meiotic double strand break repair.” 2016. Web. 27 Nov 2020.

Vancouver:

Soukup RJ. The roles of hMSH4-hMSH5 and hMLH1-hMLH3 in meiotic double strand break repair. [Internet] [Doctoral dissertation]. The Ohio State University; 2016. [cited 2020 Nov 27]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1480641841905001.

Council of Science Editors:

Soukup RJ. The roles of hMSH4-hMSH5 and hMLH1-hMLH3 in meiotic double strand break repair. [Doctoral Dissertation]. The Ohio State University; 2016. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1480641841905001

2. Chevigny, Nicolas. Caractérisation des fonctions de TRCF et de RADA dans l'expression et la maintenance des génomes des organelles chez Arabidopsis thaliana : Characterization of TRCF and RADA functions in the expression and maintenance of organelle genomes in Arabidopsis thaliana.

Degree: Docteur es, Aspects moléculaires et cellulaires de la biologie, 2019, Université de Strasbourg

La mitochondrie et le chloroplaste possèdent un génome dont l’expression et la maintenance dépendent de facteurs codés par le génome nucléaire. L’ADN mitochondrial des plantes (ADNmt) est caractérisé par d’importantes activités de recombinaison qui modulent sa structure et contribuent à son évolution. Au cours de ma thèse, j’ai caractérisé l’hélicase RADA qui est impliquée dans les étapes tardives de la recombinaison homologue organellaire. RADA possède des fonctions similaires à son homologue bactérien (RadA), mais semble jouer un rôle plus important dans les organelles de plantes. L’expression du génome chloroplastique (ADNcp) repose sur deux types d’ARN polymérases : la NEP, codés par le génome nucléaire et la PEP, codés par l’ADNcp. Durant ma thèse, j’ai également étudié le rôle de TRCF, homologue du facteur Mfd et adressé aux chloroplastes. Chez les bactéries, Mfd est impliqué dans le dégagement des ARN polymérases bloquées par des lésions et le recrutement de facteurs de réparation. Chez Arabidopsis, TRCF n’est plus impliqué dans la réparation, mais semble jouer un rôle dans la régulation de l’expression des gènes chloroplastiques.

The mitochondria and chloroplasts have their own genomes whose expression and maintenance depend on factors encoded by the nuclear genome. The plant mitochondrial DNA (mtDNA) is characterized by important recombination activities that modulate its structure and contribute to its evolution. During my thesis, I characterized the RADA helicase that is involved in the late stages of organelle homologous recombination. RADA has similar functions to its bacterial homolog (RadA), but seems to play a more important role in plant organelles. The expression of the chloroplast genome (cpDNA) relies on two types of RNA polymerases: NEP encoded by the nuclear genome and PEP encoded by the cpDNA. During my thesis, I also studied the role of TRCF, an homolog of the Mfd factor which is addressed to chloroplasts. In bacteria, Mfd is involved in the release of stalled RNA polymerases by lesions and the recruitment of repair factors. In Arabidopsis, TRCF is no longer involved in repair but appears to play a role in the regulation of chloroplast gene expression.

Advisors/Committee Members: Gualberto, José (thesis director).

Subjects/Keywords: ADNmt, recombinaison; Migration de branche; RADA; ADNcp régulation de l’expression; PEP; TRCF; MtDNA, recombination; Branch migration; RADA; CDNA expression regulation; PEP; TRCF; 572.8

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Chevigny, N. (2019). Caractérisation des fonctions de TRCF et de RADA dans l'expression et la maintenance des génomes des organelles chez Arabidopsis thaliana : Characterization of TRCF and RADA functions in the expression and maintenance of organelle genomes in Arabidopsis thaliana. (Doctoral Dissertation). Université de Strasbourg. Retrieved from http://www.theses.fr/2019STRAJ042

Chicago Manual of Style (16th Edition):

Chevigny, Nicolas. “Caractérisation des fonctions de TRCF et de RADA dans l'expression et la maintenance des génomes des organelles chez Arabidopsis thaliana : Characterization of TRCF and RADA functions in the expression and maintenance of organelle genomes in Arabidopsis thaliana.” 2019. Doctoral Dissertation, Université de Strasbourg. Accessed November 27, 2020. http://www.theses.fr/2019STRAJ042.

MLA Handbook (7th Edition):

Chevigny, Nicolas. “Caractérisation des fonctions de TRCF et de RADA dans l'expression et la maintenance des génomes des organelles chez Arabidopsis thaliana : Characterization of TRCF and RADA functions in the expression and maintenance of organelle genomes in Arabidopsis thaliana.” 2019. Web. 27 Nov 2020.

Vancouver:

Chevigny N. Caractérisation des fonctions de TRCF et de RADA dans l'expression et la maintenance des génomes des organelles chez Arabidopsis thaliana : Characterization of TRCF and RADA functions in the expression and maintenance of organelle genomes in Arabidopsis thaliana. [Internet] [Doctoral dissertation]. Université de Strasbourg; 2019. [cited 2020 Nov 27]. Available from: http://www.theses.fr/2019STRAJ042.

Council of Science Editors:

Chevigny N. Caractérisation des fonctions de TRCF et de RADA dans l'expression et la maintenance des génomes des organelles chez Arabidopsis thaliana : Characterization of TRCF and RADA functions in the expression and maintenance of organelle genomes in Arabidopsis thaliana. [Doctoral Dissertation]. Université de Strasbourg; 2019. Available from: http://www.theses.fr/2019STRAJ042

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