-
[
J Biol Chem,
1998]
Tyrosine O-sulfation, a common post-translational modification in eukaryotes, is mediated by Golgi enzymes that catalyze the transfer of the sulfuryl group from 3'-phosphoadenosine 5'-phosphosulfate to tyrosine residues in polypeptides. We recently isolated cDNAs encoding human and mouse tyrosylprotein sulfotransferase-1 (Ouyang, Y. B., Lane, W. S., and Moore, K. L. (1998) Proc. Natl. Acad. Sci. U. S. A. 95, 2896-2901). Here we report the isolation of cDNAs encoding a second tyrosylprotein sulfotransferase (TPST), designated TPST-2. The human and mouse TPST-2 cDNAs predict type II transmembrane proteins of 377 and 376 amino acid residues, respectively. The cDNAs encode functional N-glycosylated enzymes when expressed in mammalian cells. In addition, preliminary analysis indicates that TPST-1 and TPST-2 have distinct specificities toward peptide substrates. The human TPST-2 gene is on chromosome 22q12.1, and the mouse gene is in the central region of chromosome 5. We have also identified a cDNA that encodes a TPST in the nematode Caenorhabditis elegans that maps to the right arm of chromosome III. Thus, we have identified two new members of a class of membrane-bound sulfotransferases that catalyze tyrosine O-sulfation. These enzymes may catalyze tyrosine O-sulfation of a variety of protein substrates involved in diverse physiologic functions.
-
[
Dev Cell,
2022]
In a recent issue of Nature Cell Biology, Ouyang etal. examined the dynamics of double-stranded-RNA-induced gene-silencing across the Caenorhabditis elegans germline and in different subcellular locations. They distinguished among several small RNA amplification loops which complement each other and only together achieve full gene expression inhibition.
-
[
Biomaterials,
2011]
In vitro or in vivo bioimaging utilizing the upconversion (UC) luminescence of rare earth fluoride nanocrystals (NCs) has attracted much attention, especially for Yb(3+)/Tm(3+) doped NCs with a near-infrared (NIR) UC emission at 800 nm. Herein, water-soluble NaYF(4):Yb,Tm NCs with strong NIR UC emission were synthesized with a solvothermal method. In vitro and in vivo bioimaging and toxicity assessments were carried out with HeLa cell and Caenorhabditis elegans (C. elegans) cases, respectively. NaYF(4):Yb,Tm NCs afforded an efficient NIR image of the HeLa cells with an incubation concentration of 10 g mL(-1), and CCK-8 assay revealed a low cytotoxicity. Fed with Escherichia coli (E. coli) and NCs together, the C. elegans showed a NIR image in the gut from the pharynx to the anus. Further, these NCs could be excreted out when those worms were then fed with only E. coli. Toxicity studies were further addressed with protein expression, life span, egg production, egg viability, and growth rate of the worms in comparison with those of the intact ones. The feeding of rare earth fluoride NCs with a dose of 100 g does not arise obvious toxicity effect from the growth to procreation. The in vitro and in vivo studies confirm that NaYF(4):Yb,Tm NCs could be served as an excellent NIR emission bioprobe with low toxicity.
-
[
J Mol Histol,
2005]
NF-Y is a conserved trimer with histone-like subunits that binds and activates the common CCAAT promoter element.C.elegansNF-Y genes present two CeNF-YAs, a unique feature in kingdoms other than plants, one CeNF-YB and one CeNF-YC. The expression of both CeNF-YAs is restricted to the gonads and developing embryos, whereas the histone-like CeNF-YB- and CeNF-YC are also present in the pharyngeal bulb, in the neurons of ganglia surrounding the pharynx and in sensory organs of the head. Moreover, in infertile, 12-day-old worms, expression of the three subunits falls dramatically in the gonads. Our data indicate that NF-Y is not ubiquitously expressed.
-
[
PLoS One,
2009]
The pinewood nematode (PWN), Bursaphelenchus xylophilus, is a mycophagous and phytophagous pathogen responsible for the current widespread epidemic of the pine wilt disease, which has become a major threat to pine forests throughout the world. Despite the availability of several preventive trunk-injection agents, no therapeutic trunk-injection agent for eradication of PWN currently exists. In the characterization of basic physiological properties of B. xylophilus YB-1 isolates, we established a high-throughput screening (HTS) method that identifies potential hits within approximately 7 h. Using this HTS method, we screened 206 compounds with known activities, mostly antifungal, for antinematodal activities and identified HWY-4213 (1-n-undecyl-2-[2-fluorphenyl] methyl-3,4-dihydro-6,7-dimethoxy-isoquinolinium chloride), a highly water-soluble protoberberine derivative, as a potent nematicidal and antifungal agent. When tested on 4 year-old pinewood seedlings that were infected with YB-1 isolates, HWY-4213 exhibited a potent therapeutic nematicidal activity. Further tests of screening 39 Caenorhabditis elegans mutants deficient in channel proteins and B. xylophilus sensitivity to Ca(2+) channel blockers suggested that HWY-4213 targets the calcium channel proteins. Our study marks a technical breakthrough by developing a novel HTS method that leads to the discovery HWY-4213 as a dual-acting antinematodal and antifungal compound.
-
[
Methods Mol Biol,
2022]
Laser microsurgery allows the user to ablate cell bodies or disconnect nerve fibers by using a laser microbeam focused through a microscope. This technique was pioneered in C. elegans where it led to exciting discoveries in the fields of development and neurobiology. All neurons studied so far in C. elegans can regenerate and regrow axons and dendrites after injury, allowing studies of the molecular and cellular basis of neuroregeneration. In this chapter, we describe how to assemble and operate a platform for Yb-doped fiber laser microsurgery. The novel laser setup described here is a more robust, lower cost, and user-friendly alternative to other femtosecond-pulsed laser systems.
-
[
J Mater Chem,
2011]
-NaYF(4) : Yb,Er upconversion nanoparticles (UCNPs) can emit bright green fluorescence under near-infrared (NIR) light excitation which is safe to the body and can penetrate deeply into tissues. The application of UCNPs in biolabeling and imaging has received great attention recently. In this work, -NaYF(4) : Yb,Er UCNPs with an average size of 35 nm, uniformly spherical shape, and surface modified with amino groups were synthesized by a one-step green solvothermal approach through the use of room-temperature ionic liquids as the reactant, co-solvent and template. The as-prepared UCNPs were introduced into Caenorhabditis elegans (C. elegans) to achieve successful in vivo imaging. We found that longer incubation time, higher UCNP concentration and smaller UCNP size can make the in vivo fluorescence of C. elegans much brighter and more continuous along their body. The worms have no apparent selectivity on ingestion of the UCNPs capped with different capping ligands while having similar size and shape. The next generation of worms did not show fluorescence under excitation. In addition, low toxicity of the nanoparticles was demonstrated by investigating the survival rates of the worms in the presence of the UCNPs. Our work demonstrates the potential application of the UCNPs in studying the biological behavior of organisms, and lays the foundation for further development of the UCNPs in the detection and diagnosis of diseases.
-
[
ACS Cent Sci,
2019]
Upconverting nanoparticles (UCNPs) are promising tools for background-free imaging and sensing. However, their usefulness for <i>in vivo</i> applications depends on their biocompatibility, which we define by their optical performance in biological environments and their toxicity in living organisms. For UCNPs with a ratiometric color response to mechanical stress, consistent emission intensity and color are desired for the particles under nonmechanical stimuli. Here, we test the biocompatibility and mechanosensitivity of -NaYF<sub>4</sub>:Yb,Er@NaLuF<sub>4</sub> nanoparticles. First, we ligand-strip these particles to render them dispersible in aqueous media. Then, we characterize their mechanosensitivity (30% in the red-to-green spectral ratio per GPa), which is nearly 3-fold greater than those coated in oleic acid. We next design a suite of <i>ex vivo</i> and <i>in vivo</i> tests to investigate their structural and optical properties under severalbiorelevant conditions: over time in various buffers types, as a function of pH, and <i>in vivo</i> along the digestive tract of <i>Caenorhabditis elegans</i> worms. Finally, to ensure that the particles do not perturb biological function in <i>C. elegans</i>, we assess the chronic toxicity of nanoparticle ingestion using a reproductive brood assay. In these ways, we determine that mechanosensitive UCNPs are biocompatible, i.e., optically robust and nontoxic, for use as <i>in vivo</i> sensors to study animal digestion.
-
[
Cell Stress Chaperones,
2001]
The small heat shock proteins Hsp 12.2 and (alphaB-crystallin differ in that the former occurs as tetramers, without chaperonelike activity, whereas the latter forms multimers and is a good chaperone. To investigate whether the lack of chaperone activity of Hspl 2.2 is primarily due to its tetrameric structure or rather to intrinsic sequence features, we engineered chimeric proteins by swapping the N-terminal, C-terminal, and tail regions of Hsp12.2 and alphaB-crystallin, designated as n-c-t and N-C-T, respectively. Three of the chimeric sHsps, namely N-c-T, n-c-T, and N-C-t, showed nativelike secondary and quaternary structures as measured by circular dichroism and gel permeation chromatography. Combining the conserved a-crystallin domain of Hsp12.2 with the N-terminal and tail regions of (YB-crystallin (N-c-T) resulted in multimeric complexes, but did not restore chaperonelike activity. Replacing the tail region of Hsp12.2 with that of alphaB-crystallin (n-c-T) did not alter the tetrameric structure and lack of chaperone activity. Similarly, providing (alphaB-crystallin with the tail of Hsp12.2 (N-C-t) did not substantially influence the multimeric complex size, but it reduced the chaperoning ability, especially for small substrates. These results suggest that the conserved alpha -crystallin domain of Hsp12.2 is intrinsically unsuitable to confer chaperonelike activity and confirms that the tail region in alphaB-crystallin modulates chaperonelike capacity in a substrate-dependent manner.
-
[
Proc Natl Acad Sci U S A,
1998]
Tyrosylprotein sulfotransferase (TPST) is a 54- to 50-kDa integral membrane glycoprotein of the trans-Golgi network found in essentially all tissues investigated, catalyzing the tyrosine O-sulfation of soluble and membrane proteins passing through this compartment. Here we describe (i) an approach to identify the TPST protein, referred to as MSC (modification after substrate crosslinking) labeling, which is based on the crosslinking of a substrate peptide to TPST followed by intramolecular [35S]sulfate transfer from the cosubstrate 3'-phosphoadenosine 5'-phosphosulfate (PAPS); and (ii) the molecular characterization of a human TPST, referred to as TPST-2, whose sequence is distinct from that reported [TPST-1; Ouyang, Y.-B., Lane, W. S. & Moore, K. L. (1998) Proc. Natl. Acad. Sci. USA 95, 2896-2901] while this study was in progress. Human TPST-2 is a type II transmembrane protein of 377 aa residues that is encoded by a ubiquitously expressed 1.9-kb mRNA originating from seven exons of a gene located on chromosome 22 (22q12.1). A 304-residue segment in the luminal domain of TPST-2 shows 75% amino acid identity to the corresponding segment of TPST-1, including conservation of the residues implicated in the binding of PAPS. Expression of the TPST-2 cDNA in CHO cells resulted in an approximately 13-fold increase in both TPST protein, as determined by MSC labeling, and TPST activity. A predicted 359-residue type II transmembrane protein in Caenorhabditis elegans with 45% amino acid identity to TPST-2 in a 257-residue segment of the luminal domain points to the evolutionary conservation of the TPST protein family.