Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Language
Year
  • 1
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 14 July 2015, Vol.112(28), pp.8579-83
    Description: The variable domains of Ig and T-cell receptor genes in vertebrates are assembled from gene fragments by the V(D)J recombination process. The RAG1-RAG2 recombinase (RAG1/2) initiates this recombination by cutting DNA at the borders of recombination signal sequences (RSS) and their neighboring gene segments. The RAG1 protein is also known to contain a ubiquitin E3 ligase activity, located in an N-terminal region that is not strictly required for the basic recombination reaction but helps to regulate recombination. The isolated E3 ligase domain was earlier shown to ubiquitinate one site in a neighboring RAG1 sequence. Here we show that autoubiquitination of full-length RAG1 at this specific residue (K233) results in a large increase of DNA cleavage by RAG1/2. A mutational block of the ubiquitination site abolishes this effect and inhibits recombination of a test substrate in mouse cells. Thus, ubiquitination of RAG1, which can be promoted by RAG1's own ubiquitin ligase activity, plays a significant role in governing the level of V(D)J recombination activity.
    Keywords: Diversification ; Immunoglobulin ; Ubiquitin ; Ubiquitination ; V(D)J Recombination ; Homeodomain Proteins -- Metabolism
    ISSN: 00278424
    E-ISSN: 1091-6490
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    In: Nature, 2015
    Description: V(D)J recombination in the vertebrate immune system generates a highly diverse population of immunoglobulins and T-cell receptors by combinatorial joining of segments of coding DNA. The RAG1–RAG2 protein complex initiates this site-specific recombination by cutting DNA at specific sites flanking the coding segments. Here we report the crystal structure of the mouse RAG1–RAG2 complex at 3.2 Å resolution. The 230-kilodalton RAG1–RAG2 heterotetramer is ‘Y-shaped’, with the amino-terminal domains of the two RAG1 chains forming an intertwined stalk. Each RAG1–RAG2 heterodimer composes one arm of the ‘Y’, with the active site in the middle and RAG2 at its tip. The RAG1–RAG2 structure rationalizes more than 60 mutations identified in immunodeficient patients, as well as a large body of genetic and biochemical data. The architectural similarity between RAG1 and the hairpin-forming transposases Hermes and Tn5 suggests the evolutionary conservation of these DNA rearrangements. Journal Article.
    Keywords: Materials Science;
    ISSN: 0028-0836
    E-ISSN: 14764687
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 28 December 2010, Vol.107(52), pp.22487-92
    Description: Gene assembly of the variable domain of antigen receptors is initiated by DNA cleavage by the RAG1-RAG2 protein complex at sites flanking V, D, and J gene segments. Double-strand breaks are produced via a single-strand nick that is converted to a hairpin end on coding DNA and a blunt end on the neighboring recombination signal sequence. We demonstrate that the C-terminal regions of purified murine RAG1 (aa 1009-1040) and RAG2 (aa 388-520, including a plant homeodomain [PHD domain]) collaborate to inhibit the hairpinning stage of DNA cleavage. The C-terminal region of RAG2 stabilizes the RAG1/2 heterotetramer but destabilizes the RAG-DNA precleavage complex. This destabilization is reversed by binding of the PHD domain to a histone H3 peptide trimethylated on lysine 4 (H3K4me3). The addition of H3K4me3 likewise alleviates the RAG1/RAG2 C-terminus-mediated inhibition of hairpinning and the PHD-mediated inhibition of transposition activity. Thus a negative regulatory function of the noncore regions of RAG1/2 limits the RAG endonuclease activity in the absence of an activating methylated histone tail bound to the complex.
    Keywords: DNA Cleavage ; Recombination, Genetic ; DNA-Binding Proteins -- Metabolism ; Homeodomain Proteins -- Metabolism ; Vdj Exons -- Genetics
    ISSN: 00278424
    E-ISSN: 1091-6490
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 11 June 2013, Vol.110(24), pp.9873-8
    Description: The ability to sense metabolic stress is critical for successful cellular adaptation. In eukaryotes, the AMP-activated protein kinase (AMPK), a highly conserved serine/threonine kinase, functions as a critical metabolic sensor. AMPK is activated by the rising ADP/ATP and AMP/ATP ratios during conditions of energy depletion and also by increasing intracellular Ca(2+). In response to metabolic stress, AMPK maintains energy homeostasis by phosphorylating and regulating proteins that are involved in many physiological processes including glucose and fatty acid metabolism, transcription, cell growth, mitochondrial biogenesis, and autophagy. Evidence is mounting that AMPK also plays a role in a number of pathways unrelated to energy metabolism. Here, we identify the recombination-activating gene 1 protein (RAG1) as a substrate of AMPK. The RAG1/RAG2 complex is a lymphoid-specific endonuclease that catalyzes specific DNA cleavage during V(D)J recombination, which is required for the assembly of the Ig and T-cell receptor genes of the immune system. AMPK directly phosphorylates RAG1 at serine 528, and the phosphorylation enhances the catalytic activity of the RAG complex, resulting in increased cleavage of oligonucleotide substrates in vitro, or increased recombination of an extrachromosomal substrate in a cellular assay. Our results suggest that V(D)J recombination can be regulated by AMPK activation, providing a potential new link between metabolic stress and development of B and T lymphocytes.
    Keywords: Energy Coupling ; Immune Diversity ; V(D)J Recombination ; Amp-Activated Protein Kinases -- Metabolism ; Homeodomain Proteins -- Metabolism ; Serine -- Metabolism
    ISSN: 00278424
    E-ISSN: 1091-6490
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: The Journal of biological chemistry, 05 June 2015, Vol.290(23), pp.14618-25
    Description: Mammalian immune receptor diversity is established via a unique restricted set of site-specific DNA rearrangements in lymphoid cells, known as V(D)J recombination. The lymphoid-specific RAG1-RAG2 protein complex (RAG1/2) initiates this process by binding to two types of recombination signal sequences (RSS), 12RSS and 23RSS, and cleaving at the boundaries of RSS and V, D, or J gene segments, which are to be assembled into immunoglobulins and T-cell receptors. Here we dissect the ordered assembly of the RAG1/2 heterotetramer with 12RSS and 23RSS DNAs. We find that RAG1/2 binds only a single 12RSS or 23RSS and reserves the second DNA-binding site specifically for the complementary RSS, to form a paired complex that reflects the known 12/23 rule of V(D)J recombination. The assembled RAG1/2 paired complex is active in the presence of Mg(2+), the physiologically relevant metal ion, in nicking and double-strand cleavage of both RSS DNAs to produce a signal-end complex. We report here the purification and initial crystallization of the RAG1/2 signal-end complex for atomic-resolution structure elucidation. Strict pairing of the 12RSS and 23RSS at the binding step, together with information from the crystal structure of RAG1/2, leads to a molecular explanation of the 12/23 rule.
    Keywords: DNA Cleavage ; DNA Endonuclease ; DNA Enzyme ; V(D)J Recombination ; Immunodeficiency ; Mammal ; Mammalian Expression ; Metal Ions ; Protein Complex ; Protein Crystallization ; DNA Cleavage ; DNA -- Metabolism ; DNA-Binding Proteins -- Metabolism ; Homeodomain Proteins -- Metabolism
    E-ISSN: 1083-351X
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    In: Nature, 2000, Vol.404(6780), p.823
    Description: DNA is vulnerable to many types of damage resulting from environmental insults or intrinsic cellular processes. So it is not surprising that cells possess a variety of DNA-repair systems. Several of these systems--referred to as "caretakers"--are essential for maintaining genomic stability, offering protection from cancer-causing (oncogenic) mutations or chromosome rearrangements. Numbered among known caretaker proteins are those involved in repairing a variety of different types of DNA breaks, but conspicuous for their absence were the non-homologous-end-joining (NHEJ) proteins. These proteins are important for resolving both random DNA breaks produced by environmental agents (such as ionizing radiation) and specific breaks introduced during lymphocyte differentiation by programmed rearrangements of the genes encoding antigen receptors. Thanks to recent work, however--including that of Difilippantonio and colleagues (published a few weeks ago in Nature) and Gao and others (writing on page 897 of this issue)--we can add NHEJ proteins to the list of genome guardians.
    Keywords: Cancer ; DNA Damage ; DNA Repair ; Reviews ; Nhej Proteins ; Non-Homologous-End-Joining Proteins ; Reviews ; Nhej Proteins ; Non-Homologous-End-Joining Proteins;
    ISSN: 0028-0836
    E-ISSN: 1476-4687
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: PLoS ONE, 2011, Vol.6(9), p.e24571
    Description: Antibodies are assembled by a highly orchestrated series of recombination events during B cell development. One of these events, class switch recombination, is required to produce the IgG, IgE and IgA antibody isotypes characteristic of a secondary immune response. The action of the enzyme activation induced cytidine deaminase is now known to be essential for the initiation of this recombination event. Previous studies have demonstrated that the immunoglobulin switch regions acquire distinct histone modifications prior to recombination. We now present a high resolution analysis of these histone modifications across the IgE switch region prior to the initiation of class switch recombination in primary human B cells and the human CL-01 B cell line. These data show that upon stimulation with IL-4 and an anti-CD40 antibody that mimics T cell help, the nucleosomes of the switch regions are highly modified on histone H3, accumulating acetylation marks and tri-methylation of lysine 4. Distinct peaks of modified histones are found across the switch region, most notably at the 5′ splice donor site of the germline (I) exon, which also accumulates AID. These data suggest that acetylation and K4 tri-methylation of histone H3 may represent marks of recombinationally active chromatin and further implicates splicing in the regulation of AID action.
    Keywords: Research Article ; Biology ; Medicine ; Immunology ; Molecular Biology
    E-ISSN: 1932-6203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 14 December 2010, Vol.107(50), pp.21553-21557
    Description: Fanconi anemia (FA) is a rare genetic disease characterized by congenital defects, bone marrow failure, chromosomal instability, and cancer susceptibility. One hallmark of cells from FA patients is hypersensitivity to interstrand cross-linking agents, such as the chemotherapeutics cisplatin and mitomycin C (MMC). We have recently characterized a FANCD2/FANCI-associated nuclease, KIAA1018/FAN1, the depletion of which sensitizes human cells to these agents. However, as the down-regulation of FAN1 in human cells was mediated by siRNA and thus only transient, we were unable to study the long-term effects of FAN1 loss on chromosomal stability. We now describe the generation of chicken DT40 B cells, in which the FAN1 locus was disrupted by gene targeting. FAN1-null cells are highly sensitive to cisplatin and MMC, but not to ionizing or UV radiation, methyl methanesulfonate, or camptothecin. The cells do not display elevated sister chromatid exchange frequencies, either sporadic or MMC-induced. Interestingly, MMC treatment causes chromosomal instability that is quantitatively, but not qualitatively, comparable to that seen in FA cells. This finding, coupled with evidence showing that DT40 cells deficient in both FAN1 and FANCC, or FAN1 and FANCJ, exhibited increased sensitivity to cisplatin compared with cells lacking only FAN1, suggests that, despite its association with FANCD2/FANCI, FAN1 in DT40 cells participates in the processing of damage induced by interstrand cross-linking-generating agents also independently of the classical FA pathway.
    Keywords: Biological sciences -- Biology -- Cytology -- Lymphocytes ; Physical sciences -- Chemistry -- Chemical compounds -- Lymphocytes ; Biological sciences -- Biology -- Genetics -- Lymphocytes ; Health sciences -- Medical conditions -- Disorders -- Lymphocytes ; Biological sciences -- Biology -- Physiology -- Lymphocytes ; Biological sciences -- Biology -- Genetics -- Lymphocytes ; Biological sciences -- Biology -- Cytology -- Lymphocytes ; Biological sciences -- Biology -- Genetics -- Lymphocytes ; Physical sciences -- Chemistry -- Chemical compounds -- Lymphocytes ; Biological sciences -- Biology -- Genetics -- Lymphocytes
    ISSN: 00278424
    E-ISSN: 10916490
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 18 May 2010, Vol.107(20), pp.9123-9128
    Description: Cleavage of viral DNA by the bacterial Type III Restriction-Modification enzymes requires the ATP-dependent long-range communication between a distant pair of DNA recognition sequences. The classical view is that Type III endonuclease activity is only activated by a pair of asymmetric sites in a specific head-to-head inverted repeat. Based on this assumption and due to the presence of helicase domains in Type III enzymes, various motor-driven DNA translocation models for communication have been suggested. Using both single-molecule and ensemble assays we demonstrate that Type III enzymes can also cleave DNA with sites in tail-to-tail repeat with high efficiency. The ability to distinguish both inverted repeat substrates from direct repeat substrates in a manner independent of DNA topology or accessory proteins can only be reconciled with an alternative sliding mode of communication.
    Keywords: Physical sciences -- Chemistry -- Chemical compounds ; Physical sciences -- Chemistry -- Chemical compounds ; Biological sciences -- Biology -- Genetics ; Applied sciences -- Materials science -- Materials ; Physical sciences -- Physics -- Mechanics ; Applied sciences -- Technology -- Tools ; Physical sciences -- Physics -- Microphysics ; Biological sciences -- Biology -- Genetics ; Applied sciences -- Engineering -- Mechanical engineering ; Physical sciences -- Chemistry -- Chemical compounds
    ISSN: 00278424
    E-ISSN: 10916490
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 06 November 2001, Vol.98(23), pp.12926-12931
    Description: Rearrangement of gene segments to generate antigen receptor coding regions depends on the RAG1/2 recombinase, which assembles a synaptic complex between two DNA signal sequences and then cleaves the DNA directly adjacent to the paired signals. After coupled cleavage of complementary signal sequences, virtually all of the cleaved signal ends remained associated with RAG1/2 in stable complexes. These signal end complexes were distinct from various precleavage RAG1/2 signal complexes in that they were resistant to treatment with heparin. A mammalian joining apparatus consisting of purified Ku70/86, XRCC4, and DNA ligase IV proteins was sufficient to join deproteinized cleaved ends, but retention of signal sequences within the signal end complex blocked access to the DNA ends and prevented their joining by these proteins. Sequestration of cleaved ends within the signal end complex would account for the persistence of these ends in the cell after cleavage and may explain why they do not normally activate the DNA-damage-dependent cell cycle checkpoint.
    Keywords: Physical sciences -- Chemistry -- Chemical compounds -- Lymphocytes ; Applied sciences -- Materials science -- Materials -- Lymphocytes ; Physical sciences -- Chemistry -- Chemical compounds -- Lymphocytes ; Biological sciences -- Biology -- Genetics -- Lymphocytes ; Physical sciences -- Chemistry -- Chemical compounds -- Lymphocytes ; Physical sciences -- Chemistry -- Chemical compounds -- Lymphocytes ; Health sciences -- Medical treatment -- Medical procedures -- Lymphocytes ; Biological sciences -- Biology -- Physiology -- Lymphocytes ; Applied sciences -- Laboratory techniques -- Nucleic acid amplification techniques -- Lymphocytes ; Physical sciences -- Physics -- Mechanics -- Lymphocytes
    ISSN: 00278424
    E-ISSN: 10916490
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages