microPublication biology最新文献

Expansion microscopy is a powerful technique for achieving nanoscale resolution, but labelling and detection using fluorescent proteins (FPs) have been hampered by signal degradation during expansion. Current approaches therefore rely heavily on immunostaining, ssDNA-FISH or HALO/SNAP-based detection systems. Here we show that substituting tyrosine with 3-iodotyrosine in the chromophore of superfolder GFP dramatically improves signal retention during expansion microscopy in zebrafish embryos. This enhancement specifically protects FPs during the formaldehyde-dependent anchoring step, and may additionally reflect better tolerance of the prolonged acidic conditions encountered during anchoring. 3-iodotyrosine-modified FPs open a door to reliable protein-based expansion microscopy.

We report the discovery and characterization of four phages infecting Arthrobacter globiformis B-2979 that are all assigned to actinobacteriophage subcluster AS3 based on gene content similarity. These phages have genomes of approximately 38 kbp, with 66-71 predicted protein-coding genes and no tRNA genes. Genome architecture suggests that these phage are temperate. An attP core sequence with homology to host tRNA-fMet has been identified.

Soil-transmitted helminth infections are widespread and can impair children's nutrition and development. Anthelmintics may interact with the intestinal microbiota; however, they should not disrupt microbes, and microbial metabolism should not reduce drug efficacy. Using Caenorhabditis elegans and representative Gram-positive and Gram-negative gut bacterial lineages, Escherichia coli and Lactobacillus reuteri , respectively, we tested interactions with fluopyram, ivermectin, and levamisole. None of the drugs affected either bacterial growth, and neither bacterial lineage altered nematocidal efficacy. These results help elucidate bacteria-anthelmintic-nematode interactions using tractable experimental models; their direct relevance to in vivo intestinal infections remains to be confirmed.

Two-photon imaging with genetically encoded sensors is widely used to monitor neurophysiology. An additional fluorescent protein can provide anatomical landmarks for cell-type identification and motion detection. However, monomeric red fluorescent proteins often require a dedicated excitation laser. We made transgenic Drosophila with a long-Stokes-shift mScarlet variant ( LSSmScarlet3 ) to image alongside green sensors with a single 920-nm laser. We describe excitation and emission spectra of the expressed protein and show robust fluorescence at 920 nm in vitro and in vivo with minimal channel crosstalk. This approach can reduce equipment complexity and cost while placing functional calcium dynamics in their anatomical context.

In this study, ILM1 , a gene of unknown function, was studied in the yeast Saccharomyces cerevisiae . We investigated the sensitivity of an ILM1 deletion strain to a variety of stress conditions and compared the budding indices of wild-type and ilm1Δ strains. Our results showed that deletion of ILM1 increases sensitivity to caffeine and leads to a decrease in cell budding. These findings are consistent with a new role for ILM1 in regulating passage through the G1/S transition.

Alzheimer's disease (AD) brains are characterized by accumulations of neurofibrillary tangles and amyloid β (Aβ) plaques. Since enteric neurons express tau and the amyloid precursor protein (APP), we asked whether neurofibrillary tangles and Aβ aggregates were present in AD intestines compared to healthy controls and individuals with Parkinson's disease (PD) and Dementia with Lewy Bodies (DLB). Neuron-like APP and Aβ immunoreactivities were observed in all groups with no observable plaques. No tangle-like structures were observed in any group although p-Ser 396/404 tau immunoreactivity was seen. The enteric nervous system appears to be protected from developing tangle and plaque pathology in AD.

Acne inversa, or hidradenitis suppurativa, is a chronic inflammatory skin disorder that causes painful and reoccurring abscesses. The PSEN1 gene is responsible for the sequence coding for the presenilin 1 protein, which is part of the gamma-secretase complex and is responsible for cleaving multiple peptides. Acne inversa occurs when the Notch signaling pathway of PSEN1 is disrupted. Analysis of multiple pathogenicity predictors and simulated aqueous environments of the transmembrane protein in its native state and mutated state through molecular dynamics simulation predicted deleterious effects from swap of tyrosine to cysteine at the highly conserved and buried position 189.

Cytosine methylation is an epigenetic modification that regulates transcription. DNA demethylation occurs through oxidation of methylcytosine to hydroxymethylcytosine, making hydroxymethylation an important and translationally relevant marker of DNA methylation dynamics. These epigenetic modifications can be measured in their deoxynucleoside forms from enzymatically digested DNA by liquid chromatography-mass spectrometry (LC-MS). However, 5-hydroxymethyl-2'-deoxycytidine (5hmdC) co-elutes with 2'-deoxycytidine (dC). Because 5hmdC represents <0.05% of total dC in DNA, co-elution with dC causes ion suppression that limits detection and quantitation. Here, we present a chromatographic method that separates 5hmdC from dC, eliminates ion suppression, and improves the sensitivity of 5hmdC detection.

Glia regulate neuronal function and organismal physiology, but how glial mechanisms control proteostasis across tissues remains incompletely understood. We showed that alkalinization of Amphid sheath (AMsh) glia, achieved by loss of the chloride channel clh-1 or overexpression of the carbonic anhydrase cah-4 , promotes longevity and stress resistance. While these studies established a role for glial pH in aging, the effects of cah-4 overexpression on autophagy and proteostasis were not examined. Here, we show that cah-4 overexpression in AMsh glia increases autophagy locally and systemically, and reduces neuronal polyglutamine aggregation. These data confirm that glial alkalinization promotes local and systemic proteostasis.

A recent paper describes an improved method for producing human ribosomal proteins in the soluble fraction of bacterial lysates rather than in inclusion bodies. We have extended this approach to clone, express, and purify additional proteins from the small ribosomal subunit for use in enzymatic and structural assays, as well as protein-protein interaction studies. Here, we show that an N-terminal 6×His-Trx tag enables the soluble expression and purification of human RPS3/uS3, RPS12/eS12, and RPS14/uS11 from E. coli cells. These results expand the repertoire of human ribosomal proteins available for individual characterization outside of the intact ribosomal complex.