RESUMO
As the novel infection with SARS-CoV-2 emerges, objective assessment of the scientific plausibility of nutraceutical and botanical interventions for prevention and treatment is important. We evaluate twelve such interventions with mechanisms of action that modulate the immune system, impair viral replication, and/or have been demonstrated to reduce severity of illness. These are examples of interventions that, mechanistically, can help protect patients in the presence of the prevalent and infectious SARS-CoV-2 virus. While there are limited studies to validate these agents to specifically prevent COVID-19, they have been chosen based upon their level of evidence for effectiveness and safety profiles, in the context of other viral infections. These agents are to be used in a patient-specific manner in concert with lifestyle interventions known to strengthen immune response (see related article in this issue of IMCJ).
RESUMO
We have previously identified a cDNA encoding part of the amino terminal portion of the large subunit of replication factor c (RF-C, AP-1), which we have named VDJP. Analysis of VDJP demonstrated that it has amino acid homology to bacterial DNA ligases and specific binding to the nonamer portion of the V(D)J recombination signal sequence motif. In this report, we demonstrate that VDJP is capable of forming a covalent bond between DNA fragments in a sequence dependent fashion. The VDJP mediated DNA ligation reaction is neither dependent on the presence of compatible DNA ends nor on sequence homology between the DNA fragments that are joined. Furthermore, we show that the covalent junction between the DNA fragments is resistant to proteases and phenol, and therefore not protein linked.
Assuntos
Replicação do DNA , Proteínas de Ligação a DNA/genética , Proteínas de Homeodomínio , Fragmentos de Peptídeos/genética , Proteínas Proto-Oncogênicas c-bcl-2 , Recombinação Genética , Proteínas Repressoras , Proteínas de Saccharomyces cerevisiae , DNA Ligases , Proteínas de Ligação a DNA/química , Escherichia coli , Exonucleases/metabolismo , Código Genético , Antígenos de Histocompatibilidade Menor , Proteínas Recombinantes de Fusão/biossíntese , Proteína de Replicação C , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido NucleicoRESUMO
A putative full-length 1.7-kb cDNA, encoding a murine protein that specifically binds to the nonamer portion of the V(D)J recombinational signal sequence (RSS) element, has been cloned. By its sequence analysis, this cDNA is identical to a portion of the 4.5-kb murine replication factor C large-subunit-encoding cDNA. By Northern blot analysis, the 1.7-kb mRNA species is observed in murine immature B cells but not in non-lymphoid cells and tissues, while the 4.5-kb replication factor C-encoding cDNA is expressed in all cell types. The deduced VDJP amino-acid sequence includes a region of homology with bacterial DNA ligases at the C terminus of each of the proteins. VDJP has been synthesized as a fusion protein in bacteria, and the purified protein has been previously shown to mediate the joining of DNA fragments in a V(D)J RSS-dependent fashion (Guilliams et al., Biochem. Biophys. Res. Commun. 202 (1994) 1134-1141).
Assuntos
DNA Ligases/genética , DNA Nucleotidiltransferases/genética , DNA Complementar/genética , Proteínas de Ligação a DNA/genética , Proteínas de Homeodomínio , Proteínas Proto-Oncogênicas c-bcl-2 , Proteínas Repressoras , Proteínas de Saccharomyces cerevisiae , Sequência de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação , DNA Nucleotidiltransferases/biossíntese , Replicação do DNA , Proteínas de Ligação a DNA/química , Escherichia coli/genética , Camundongos , Antígenos de Histocompatibilidade Menor , Dados de Sequência Molecular , Mutação , Conformação Proteica , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Proteína de Replicação C , Homologia de Sequência do Ácido Nucleico , VDJ RecombinasesRESUMO
We have previously reported the cloning of a protein, VDJP, that is capable of binding the nonamer element of the V(D)J Recombinational Signal Sequence (RSS) as well as joining linear DNA fragments containing RSS elements in vitro. We show here that the linearized DNA molecules must contain a 5' extension or blunt end in order to be joined by VDJP. DNAs with 3' extensions are not efficiently joined by VDJP. Furthermore, the joining activity of DNAs with 5' extensions is significantly increased as the distance between the end and the RSS decreases. It is not yet clear what role VDJP plays in vivo, because our assay may not mimic exactly the in vivo DNA intermediates.
