Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.48 (transcriptase)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Grafting experiments have revealed that transgenic plants that undergo co-suppression of homologous transgenes and endogenous genes or PTGS of exogenous transgenes produce a sequence-specific systemic silencing signal that is able to propagate from cell to cell and at long distance. Similarly, infection of transgenic plants by viruses that carry (part of) a transgene sequence results in global silencing (VIGS) of the integrated transgenes although viral infection is localized. Systemic PTGS and VIGS strongly resemble recovery from virus infection in non-transgenic plants, leading to protection against secondary infection in newly emerging leaves and PTGS of transiently expressed homologous transgenes. The sequence-specific PTGS signal is probably a transgene product (for example, aberrant RNA) or a secondary product (for example, RNA molecules produced by an RNA-dependent RNA polymerase with transgene RNA as a matrix) that mimics the type of viral RNA that is targeted for degradation by cellular defence. Whether some particular cases of transgene TGS could also rely on the production of such a mobile molecule is discussed.
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PMID:Systemic silencing signal(s). 1099 11

Plant gene silencing was originally thought to be a quirk of transformation procedures, but is now recognized to be a facet of vitally important gene regulatory systems, present in all organisms. Monocot plants, especially the grasses, play a foremost role in the agricultural economy of all nations, and their biotechnological manipulation offers great potential for both developed and developing countries. Here, we review reported instances of transgene silencing in monocots and relate the processes of transcriptional and post-transcriptional gene silencing (TGS, PTGS) in perspective to the rapidly burgeoning knowledge of these phenomena in many organisms. Recent findings include the involvement of an RNA-dependent RNA polymerase and a nuclease in PTGS systems and the close relationship between methylation and chromatin structure in TGS events.
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PMID:Transgene silencing in monocots. 1099 14

The suppression of gene silencing is a key mechanism for the success of viral infection in plants. DNA viruses from the Geminiviridae family encode several proteins that suppress transcriptional and post-transcriptional gene silencing (TGS/PTGS). In Begomovirus, the most abundant genus of this family, three out of six genome-encoded proteins, namely C2, C4 and V2, have been shown to suppress PTGS, with V2 being the strongest PTGS suppressor in transient assays. Beet curly top virus (BCTV), the model species for the Curtovirus genus, is able to infect the widest range of plants among geminiviruses. In this genus, only one protein, C2/L2, has been described as inhibiting PTGS. We show here that, despite the lack of sequence homology with its begomoviral counterpart, BCTV V2 acts as a potent PTGS suppressor, possibly by impairing the RDR6 (RNA-dependent RNA polymerase 6)/suppressor of gene silencing 3 (SGS3) pathway.
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PMID:V2 from a curtovirus is a suppressor of post-transcriptional gene silencing. 2893 88