The TPX family of co-repressors: a hub amidst the hubbub.

The phytohormone auxin affects a wide range of plant responses through global shifts in gene expression. The TOPLESS/TOPLESS RELATED (TPL/TPR) co-repressors (here collectively called the TPX family for simplicity) play a central role in this transcriptional regulation, acting through a variety of mechanisms, including modifying chromatin accessibility and assembling the machinery needed for transcription initiation. Structure-function analysis has mapped multiple repression domains within the founding TPL protein, and uncovered several forms of post-translational modifications that alter the function of TPL or other TPX proteins.

Florigen-producing cells express FPF1-LIKE PROTEIN 1 to accelerate flowering and stem growth in Arabidopsis.

Plants induce the expression of the florigen FLOWERING LOCUS T (FT) in response to seasonal changes. FT is expressed in a distinct subset of phloem companion cells in Arabidopsis. Using tissue-specific translatome analysis, we discovered that the FT-expressing cells also express FLOWERING PROMOTING FACTOR 1 (FPF1)-LIKE PROTEIN 1 (FLP1), specifically under long-day conditions with the red/far-red ratio of natural sunlight.

A function of TPL/TBL1-type corepressors is to nucleate the assembly of the preinitiation complex.

The plant corepressor TPL is recruited to diverse chromatin contexts, yet its mechanism of repression remains unclear. Previously, we leveraged the fact that TPL retains its function in a synthetic transcriptional circuit in the yeast model Saccharomyces cerevisiae to localize repressive function to two distinct domains. Here, we employed two unbiased whole-genome approaches to map the physical and genetic interactions of TPL at a repressed locus.

Florigen-producing cells express FPF1-LIKE PROTEIN 1 that accelerates flowering and stem growth in long days with sunlight red/far-red ratio in .

Seasonal changes in spring induce flowering by expressing the florigen, FLOWERING LOCUS T (FT), in . is expressed in unique phloem companion cells with unknown characteristics. The question of which genes are co-expressed with and whether they have roles in flowering remains elusive.

A conserved function of corepressors is to nucleate assembly of the transcriptional preinitiation complex.

The plant corepressor TPL is recruited to diverse chromatin contexts, yet its mechanism of repression remains unclear. Previously, we have leveraged the fact that TPL retains its function in a synthetic transcriptional circuit in the yeast model to localize repressive function to two distinct domains. Here, we employed two unbiased whole genome approaches to map the physical and genetic interactions of TPL at a repressed locus.

Stretching single DNA molecules to demonstrate high-force capabilities of holographic optical tweezers.

The well calibrated force-extension behaviour of single double-stranded DNA molecules was used as a standard to investigate the performance of phase-only holographic optical tweezers at high forces. Specifically, the characteristic overstretch transition at 65 pN was found to appear where expected, demonstrating (1) that holographic optical trap calibration using thermal fluctuation methods is valid to high forces; (2) that the holographic optical traps are harmonic out to >250 nm of 2.1 mum particle displacement; and (3) that temporal modulations in traps induced by the spatial light modulator (SLM) do not affect the ability of optical traps to hold and steer particles against high forces.

Subcellular Min oscillations as a single-cell reporter of the action of polycations, protamine, and gentamicin on Escherichia coli.

Background: In Escherichia coli, MinD-GFP fusion proteins show rapid pole to pole oscillations. The objective was to investigate the effects of extracellular cations on the subcellular oscillation of cytoplasmic MinD within Escherichia coli.

Methodology/principal Findings: We exposed bacteria to the extracellular cations Ca(++), Mg(++), the cationic antimicrobial peptide (CAP) protamine, and the cationic aminoglycoside gentamicin.