microPublication biology最新文献

The conserved protein kinase GCN2 orchestrates cellular adaptation to amino acid starvation and other stress. Activation of GCN2 requires direct binding to its effector protein GCN1, via the RWDBD region in GCN1. In yeast, overexpression of the RWDBD, with or without the C-terminus (CTD), elicits a dominant-negative phenotype due to impairing Gcn1-Gcn2 interaction. Here we show that overexpressed human RWDBD+CTD also causes a dominant-negative phenotype in yeast, in a manner dependent on specific amino acids. All but one amino acid is conserved from yeast to human, suggesting conservation of the GCN2 binding parameters in GCN1, with minor evolutionary divergence.

Myosin IIIA is an unconventional myosin that contains a kinase domain, and is involved in the formation of hair-cell stereocilia. To investigate its regulatory roles, we mimicked phosphorylation in mchr-MYO3AΔK constructs and assayed their ability to influence filopodial properties in COS7 cells. The phosphomimics generated fewer filopodia. Coexpression of mchr-MYO3AΔK with a GFP-construct containing only the MYO3A kinase domain also resulted in generation of fewer filopodia. Structural predictions suggest that the phosphorylation sites inhibit actin/MYO3A interactions. Taken together, these analyses link MYO3A phosphorylation with the regulation of its ability to create actin protrusions such as filopodia and stereocilia.

We developed a hydroponic system using readily available materials. This system enables uniform and quick cultivation of hundreds of rice plants with simple management. Uniform cultivation of more than 1,000 rice plants in a 1 m × 2 m space was achieved mainly by reducing the plant height with growth retardant and optimizing the arrangement of plants. Heading time under this system may vary depending on photoperiod sensitivity or other genotype-specific responses. However, under appropriate conditions, this method will be useful not only for generation advancement, but also for screening mutants under specified cultivation conditions.

Telomerase reverse transcriptase (TERT) expression increases during sexual development in Tetrahymena thermophila , when thousands of new chromosome ends require telomere addition. To define the timing of TERT mRNA accumulation, we combined cytological staging with RT-qPCR across conjugation stages. DAPI microscopy was used to score micronuclear and macronuclear morphology. TERT mRNA increased early in conjugation, peaked during meiotic prophase (crescent stage), remained elevated through post-crescent meiosis, and declined during macronuclear development before extensive de novo telomere addition. These data agree with earlier work but provide improved quantitative, temporal and cytological resolution, showing that peak TERT mRNA accumulation precedes large-scale telomere addition.

Synchronized L1 larvae are commonly maintained under starvation for varying durations prior to experimental use in Caenorhabditis elegans research. However, the effects of short-term L1 arrest duration on downstream phenotypes remain unclear. Here, we evaluated developmental growth, reproductive capacity, and locomotor behavior in worms derived from synchronized L1 populations maintained under starvation for 0-6 days before plating. No significant differences were observed in body length, body volume, brood size, embryonic viability, or locomotion among worms derived from different L1 arrest durations. These findings suggest that short-term L1 arrest duration did not significantly influence the organismal phenotypes evaluated in this study.

NIT1 is a tumor suppressor which functions as a metabolite repair enzyme to process deaminated glutathione (dGSH). Missense variants in NIT1 were analyzed from the COSMIC database to assess their structural and functional consequences. Of 59 missense variants identified, nine were flagged as deleterious. Homology modeling onto the C. elegans NitFhit structure revealed two mechanistically distinct classes: active site mutations predicted to disrupt the conserved Glu-Lys-Cys (EKC) catalytic triad and surface mutations predicted to perturb the Nit1-Fhit interaction interface. This work provides a structural basis for understanding NIT1 loss of function in human cancer.

Cyclin-dependent kinase inhibitor ( cki-1 ) is associated with cell cycle arrest and cellular quiescence. In Caenorhabditis elegans , glia-to-neuron transdifferentiation of the phasmid socket 1 (PHso1) glia into the phasmid D (PHD) neuron has been previously described across larval stages. Here, we report the post-hatching timeline of PHso1-to-PHD remodeling within L4 substages, including the loss of glial socket morphology and the acquisition of neuronal features well into adulthood. We find that cki-1 expression decreases across L4 substages between 40-50 hours post-hatching in males, while cki-1 remains robustly expressed in hermaphrodite PHso1 cells. Across L3, L4, and adulthood, PHso1 cell proportions change consistently.

Links between tumorigenesis and lipid metabolism have been observed in various cancers, but whether lipid metabolism is altered in skin cancers is not well understood. Here we show that two different mouse skin cancer cell lines accumulate more triglycerides when compared to normal keratinocytes. This suggests that lipid metabolism is altered in mouse skin cancer tumor progression and may have implications for the regulation of lipid metabolism in non-melanoma skin cancer in humans.

Ergothioneine is a widespread thiol metabolite present in fungal and bacterial species. Ergothioneine has been demonstrated to increase the lifespan of the model laboratory species C. elegans and M. musculus through increased protein crosslinking. It is rapidly gaining popularity as a fungal derived nutraceutical compound, however the complete mushrooms species distribution and ecological role of ergothioneine is unknown. We show ergothioneine concentrations appear to be highest in mushroom species that are capable of cellulose degradation. We also show that ergothioneine is a thermally stable compound and does not appear to degrade but rather increases in concentration in cooked mushrooms.

The Pristionchus pacificus ASER-specific Ppa-gcy-22 .3 and Ppa-gcy-22 .5 paralogs differ in their regulatory dependencies despite sharing an upstream terminal selector machinery. P. pacificus gcy-22.3 expression is sensitive to Ppa-die-1 and Ppa-cog-1 perturbation, while Ppa-gcy-22 .5 is largely independent of these canonical ASE laterality regulators. Both paralogs require the miRNA, Ppa-miR-8345 , for repression in ASEL; loss of Ppa-miR-8345 produces a complete ASEL-to-ASER conversion, in contrast to the hybrid ASEL/ASER states caused by Ppa-die-1 or Ppa-cog-1 mutation alone. These findings indicate Ppa-miR-8345 acts through additional regulatory outputs beyond the die-1 / cog-1 feedback loop, revealing gene-by-gene rewiring of terminal differentiation programs.