Biology subjects
Publications and source records attributed to Markina, N. M..
Jasmonic and salicylic acids are the major hormones involved in plant response to pests and pathogens. Here, we engineered autoluminescent plants that report activity of these hormones with up to 53-fold contrast. Using consumer-grade cameras, we imaged reporter Arabidopsis thaliana and Nicotiana benthamiana plants throughout normal development, and in response to attacks of pests and pathogens.
Despite the growing interest in pre-mRNA alternative splicing (AS) as a therapeutic anticancer target, the potential of splicing inhibitors in treating solid tumors remains largely unexplored. We conducted a meta-analysis of transcriptome data from six different tumor types and revealed that splicing inhibitors induced similar patterns of AS, resulting in widespread exon-skipping and intron retention events that often lead to nonsense-mediated decay of the transcripts. Interestingly, in many cases exon skipping is induced by a compensatory cellular response to splicing inhibitor treatment. It involves an upregulation of multiple splicing factors and incomplete recognition of branch points by U2 snRNP. These post transcriptional changes downregulate one-third of essential DNA repair genes, thereby creating a therapeutic vulnerability that can be exploited for cancer treatment. To harness this vulnerability, we proposed a new approach to cancer treatment consisting of sequential addition of a splicing inhibitors followed by a DNA-damaging agent. Our in vitro and in vivo experiments demonstrated that this strategy exhibits promising therapeutic potential for a wide range of tumors.
In contrast to fluorescent proteins, light emission from luciferase reporters requires exogenous addition of a luciferin substrate. Bacterial bioluminescence has been the single exception, where an operon of five genes is sufficient to produce light autonomously. Although commonly used in prokaryotic hosts, toxicity of the aldehyde substrate has limited its use in eukaryotes1. Here we demonstrate autonomous luminescence in a multicellular eukaryotic organism by incorporating a recently discovered fungal bioluminescent system2 into tobacco plants. We monitored these light-emitting plants from germination to flowering, observing temporal and spatial patterns of luminescence across time scales from seconds to months. The dynamic patterns of luminescence reflected progression through developmental stages, circadian oscillations, transport, and response to injuries. As with other fluorescent and luminescent reporters, we anticipate that this system will be further engineered for varied purposes, especially where exogenous addition of substrate is undesirable.
1Odontosyllis undecimdonta is a marine syllid polychaete that produces bright internal and exuded bioluminescence. Despite over fifty years of biochemical investigation into Odontosyllis bioluminescence, the light-emitting small molecule substrate and catalyzing luciferase protein have remained a mystery. Here we describe the discovery of a bioluminescent protein fraction from O. undecimdonta, the identification of the luciferase using peptide and RNA sequencing, and the in vitro reconstruction of the bioluminescence reaction using highly purified O. undecimdonta luciferin and recombinant luciferase. Lastly, we found no identifiably homologous proteins in publicly available datasets. This suggests that the syllid polychaetes contain an evolutionarily unique luciferase among all characterized luminous taxa.\n\n3 HighlightsO_LIThe polychaete O. undecimdonta uses a luciferin-luciferase bioluminescence system\nC_LIO_LIO. undecimdonta bioluminescence does not require additional cofactors\nC_LIO_LIThe luciferase of the Japanese fireworm is 329 amino acids long\nC_LIO_LIRecombinant luciferase is not secreted when expressed in human cells\nC_LIO_LIExogenous luciferin does not seem to penetrate cell membranes-only lysate luminesces\nC_LIO_LIThe luciferase transcript is supported by full-length cDNA reads with 5 and 3 UTR\nC_LI\n\n\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=80 SRC=\"FIGDIR/small/329631_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (25K):\norg.highwire.dtl.DTLVardef@15882beorg.highwire.dtl.DTLVardef@1efc214org.highwire.dtl.DTLVardef@1aee561org.highwire.dtl.DTLVardef@15582b7_HPS_FORMAT_FIGEXP M_FIG C_FIG