Transcriptional memory is a biological phenomenon, initially discovered in yeast, during which cells primed with a particular cue show increased rates of gene expression after re-stimulation at a later time. This event was shown to take place: in yeast during growth in galactose and inositol starvation; plants during environmental stress; in mammalian cells during LPS and

interferon Interferons (IFNs, ) are a group of signaling proteins made and released by host cells in response to the presence of several viruses. In a typical scenario, a virus-infected cell will release interferons causing nearby cells to heighten the ...

induction. Prior work has shown that certain characteristics of

chromatin Chromatin is a complex of DNA and protein found in eukaryotic cells. The primary function is to package long DNA molecules into more compact, denser structures. This prevents the strands from becoming tangled and also plays important roles in r ...

may contribute to the poised transcriptional state allowing faster re-induction. These include: activity of specific transcription factors, retention of

RNA polymerase II RNA polymerase II (RNAP II and Pol II) is a multiprotein complex that transcribes DNA into precursors of messenger RNA (mRNA) and most small nuclear RNA (snRNA) and microRNA. It is one of the three RNAP enzymes found in the nucleus of eukaryoti ...

at the promoters of poised genes, activity of

chromatin remodeling Chromatin remodeling is the dynamic modification of chromatin architecture to allow access of condensed genomic DNA to the regulatory transcription machinery proteins, and thereby control gene expression. Such remodeling is principally carried out ...

complexes, propagation of H3K4me2 and H3K36me3

histone modification In biology, histones are highly basic proteins abundant in lysine and arginine residues that are found in eukaryotic cell nuclei. They act as spools around which DNA winds to create structural units called nucleosomes. Nucleosomes in turn ar ...

s, occupancy of the H3.3 histone variant, as well as binding of

nuclear pore A nuclear pore is a part of a large complex of proteins, known as a nuclear pore complex that spans the nuclear envelope, which is the double membrane surrounding the eukaryotic cell nucleus. There are approximately 1,000 nuclear pore complexes ...

components. Moreover, locally bound

cohesin Cohesin is a protein complex that mediates sister chromatid cohesion, homologous recombination, and DNA looping. Cohesin is formed of SMC3, SMC1, SCC1 and SCC3 ( SA1 or SA2 in humans). Cohesin holds sister chromatids together after DNA rep ...

was shown to inhibit establishment of transcriptional memory in human cells during

interferon gamma Interferon gamma (IFN-γ) is a dimerized soluble cytokine that is the only member of the type II class of interferons. The existence of this interferon, which early in its history was known as immune interferon, was described by E. F. Wheelock ...

stimulation.

References

Cells Microbiology Gene therapy {{microbiology-stub