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Joseph San Filippo

Other affiliations: Hoffmann-La Roche
Bio: Joseph San Filippo is an academic researcher from Yale University. The author has contributed to research in topics: Homologous recombination & DNA repair. The author has an hindex of 8, co-authored 9 publications receiving 1992 citations. Previous affiliations of Joseph San Filippo include Hoffmann-La Roche.

Papers
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Journal ArticleDOI
TL;DR: HR accessory factors that facilitate other stages of the Rad51- and Dmc1-catalyzed homologous DNA pairing and strand exchange reaction have also been identified.
Abstract: Homologous recombination (HR) serves to eliminate deleterious lesions, such as double-stranded breaks and interstrand crosslinks, from chromosomes. HR is also critical for the preservation of repli- cation forks, for telomere maintenance, and chromosome segrega- tion in meiosis I. As such, HR is indispensable for the maintenance of genome integrity and the avoidance of cancers in humans. The HR reaction is mediated by a conserved class of enzymes termed recombinases. Two recombinases, Rad51 and Dmc1, catalyze the pairing and shuffling of homologous DNA sequences in eukaryotic cells via a filamentous intermediate on ssDNA called the presynaptic filament. The assembly of the presynaptic filament is a rate-limiting process that is enhanced by recombination mediators, such as the breast tumor suppressor BRCA2. HR accessory factors that facil- itate other stages of the Rad51- and Dmc1-catalyzed homologous DNA pairing and strand exchange reaction have also been identified. Recent progress on elucidating the mechanisms of action of Rad51 and Dmc1 and their cohorts of ancillary factors is reviewed here.

1,542 citations

Journal ArticleDOI
TL;DR: By targeting RPA and mimicking DNA, DSS1 functions with BRCA2 in a two-component homologous recombination mediator complex in genome maintenance and tumor suppression and may provide a paradigm for understanding the roles of D SS1 in other biological processes.

141 citations

Journal ArticleDOI
TL;DR: It is demonstrated by biochemical means and electron microscopy that BRC3/4-DBD nucleates hRad 51 onto ssDNA and acts as a recombination mediator in enabling hRad51 to utilize replication protein A-coated ssDNA as recombination substrate.

127 citations

Journal ArticleDOI
TL;DR: A bipartite mechanism of Hop2-Mnd1 in homologous DNA pairing is unveiled: stabilization of the Rad51 presynaptic filament and duplex DNA capture to enhance synaptic complex formation.
Abstract: The HOP2 and MND1 genes are indispensable for meiotic recombination. The products of these genes associate to form a stable heterodimeric complex that binds DNA and stimulates the recombinase activity of Rad51 and Dmc1. Here we conduct molecular studies to delineate the action mechanism of the Hop2–Mnd1 complex. We present evidence to implicate Hop2 as the major DNA-binding subunit and Mnd1 as the prominent Rad51 interaction entity. Hop2–Mnd1 stabilizes the Rad51–single-stranded DNA (ssDNA) nucleoprotein filament, the catalytic intermediate in recombination reactions. We also show that Hop2–Mnd1 enhances the ability of the Rad51–ssDNA nucleoprotein filament to capture duplex DNA, an obligatory step in the formation of the synaptic complex critical for DNA joint formation. Thus, our results unveil a bipartite mechanism of Hop2–Mnd1 in homologous DNA pairing: stabilization of the Rad51 presynaptic filament and duplex DNA capture to enhance synaptic complex formation.

107 citations

Journal ArticleDOI
TL;DR: In this article, it was shown that the RAD51 associated protein 1 (RAD51AP1) is a RAD51-interacting protein whose function has remained elusive, and that it helps maintain genomic integrity via RAD51 recombinase enhancement.

100 citations


Cited by
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
22 Oct 2009-Nature
TL;DR: The authors' improving understanding of DNA-damage responses is providing new avenues for disease management, and these responses are biologically significant because they prevent diverse human diseases.
Abstract: The prime objective for every life form is to deliver its genetic material, intact and unchanged, to the next generation. This must be achieved despite constant assaults by endogenous and environmental agents on the DNA. To counter this threat, life has evolved several systems to detect DNA damage, signal its presence and mediate its repair. Such responses, which have an impact on a wide range of cellular events, are biologically significant because they prevent diverse human diseases. Our improving understanding of DNA-damage responses is providing new avenues for disease management.

4,871 citations

Journal ArticleDOI
TL;DR: Patients lacking normal NHEJ are not only sensitive to ionizing radiation (IR), but also severely immunodeficient in the range of DNA end substrate configurations upon which they can act.
Abstract: Double-strand DNA breaks are common events in eukaryotic cells, and there are two major pathways for repairing them: homologous recombination (HR) and nonhomologous DNA end joining (NHEJ). The various causes of double-strand breaks (DSBs) result in a diverse chemistry of DNA ends that must be repaired. Across NHEJ evolution, the enzymes of the NHEJ pathway exhibit a remarkable degree of structural tolerance in the range of DNA end substrate configurations upon which they can act. In vertebrate cells, the nuclease, DNA polymerases, and ligase of NHEJ are the most mechanistically flexible and multifunctional enzymes in each of their classes. Unlike repair pathways for more defined lesions, NHEJ repair enzymes act iteratively, act in any order, and can function independently of one another at each of the two DNA ends being joined. NHEJ is critical not only for the repair of pathologic DSBs as in chromosomal translocations, but also for the repair of physiologic DSBs created during variable (diversity) joining [V(D)J] recombination and class switch recombination (CSR). Therefore, patients lacking normal NHEJ are not only sensitive to ionizing radiation (IR), but also severely immunodeficient.

2,508 citations

Journal ArticleDOI
TL;DR: This work surmises that CRI represents the seventh hallmark of cancer, and suggests that an additional mechanism involved in cancer-related inflammation (CRI) is induction of genetic instability by inflammatory mediators, leading to accumulation of random genetic alterations in cancer cells.
Abstract: Inflammatory conditions in selected organs increase the risk of cancer. An inflammatory component is present also in the microenvironment of tumors that are not epidemiologically related to inflammation. Recent studies have begun to unravel molecular pathways linking inflammation and cancer. In the tumor microenvironment, smoldering inflammation contributes to proliferation and survival of malignant cells, angiogenesis, metastasis, subversion of adaptive immunity, reduced response to hormones and chemotherapeutic agents. Recent data suggest that an additional mechanism involved in cancer-related inflammation (CRI) is induction of genetic instability by inflammatory mediators, leading to accumulation of random genetic alterations in cancer cells. In a seminal contribution, Hanahan and Weinberg [(2000) Cell, 100, 57-70] identified the six hallmarks of cancer. We surmise that CRI represents the seventh hallmark.

2,475 citations

Journal ArticleDOI
TL;DR: HR accessory factors that facilitate other stages of the Rad51- and Dmc1-catalyzed homologous DNA pairing and strand exchange reaction have also been identified.
Abstract: Homologous recombination (HR) serves to eliminate deleterious lesions, such as double-stranded breaks and interstrand crosslinks, from chromosomes. HR is also critical for the preservation of repli- cation forks, for telomere maintenance, and chromosome segrega- tion in meiosis I. As such, HR is indispensable for the maintenance of genome integrity and the avoidance of cancers in humans. The HR reaction is mediated by a conserved class of enzymes termed recombinases. Two recombinases, Rad51 and Dmc1, catalyze the pairing and shuffling of homologous DNA sequences in eukaryotic cells via a filamentous intermediate on ssDNA called the presynaptic filament. The assembly of the presynaptic filament is a rate-limiting process that is enhanced by recombination mediators, such as the breast tumor suppressor BRCA2. HR accessory factors that facil- itate other stages of the Rad51- and Dmc1-catalyzed homologous DNA pairing and strand exchange reaction have also been identified. Recent progress on elucidating the mechanisms of action of Rad51 and Dmc1 and their cohorts of ancillary factors is reviewed here.

1,542 citations