Aoki ST et al. (2016) Proc Natl Acad Sci U S A "PGL germ granule assembly protein is a base-specific, single-stranded RNase."

Aoki ST, Kimble J, Wickens M, Bingman CA, Kershner AM

[

Proc Natl Acad Sci U S A,

2016]

Cellular RNA-protein (RNP) granules are ubiquitous and have fundamental roles in biology and RNA metabolism, but the molecular basis of their structure, assembly, and function is poorly understood. Using nematode "P-granules" as a paradigm, we focus on the PGL granule scaffold protein to gain molecular insights into RNP granule structure and assembly. We first identify a PGL dimerization domain (DD) and determine its crystal structure. PGL-1 DD has a novel 13 -helix fold that creates a positively charged channel as a homodimer. We investigate its capacity to bind RNA and discover unexpectedly that PGL-1 DD is a guanosine-specific, single-stranded endonuclease. Discovery of the PGL homodimer, together with previous results, suggests a model in which the PGL DD dimer forms a fundamental building block for P-granule assembly. Discovery of the PGL RNase activity expands the role of RNP granule assembly proteins to include enzymatic activity in addition to their job as structural scaffolds.

Jiang X et al. (2020) J Fluoresc "A Water-Soluble Fluorescent Probe for the Selective Sensing of Ag⁺ and its Application in Imaging of Living Cells and Nematodes."

Deng M, Wu J, Jiang X, Li H, Yang Y, Zhou X, Qi X, Lu M, Liang S

[

J Fluoresc,

2020]

In this study, an imidazole-coumarin based fluorescent probe was developed for the selective and sensitive detection of Ag+ in aqueous solution. Using a combination of Job plot, NMR titrations, and DFT calculations, the binding properties between Ag+ and the probe were deeply investigated, and the results revealed a 1:1 binding stoichiometry between the probe and Ag+ with a binding constant of 1.02x106M-1. The detection limit was found to be 150nM, which satisfies the requirement for the quantitative detection of Ag+ in real water samples. Moreover, the new probe, Ic, was successfully applied to sense Ag+ in HeLa and HepG2 cells as well as in C. elegans, indicating that it could be a useful tool for the environmental monitoring of Ag+ pollution. These results demonstrated that Ic could serve as a high-efficiency and low-cost fluorescent probe for tracking Ag+ in an aquatic environment and biological organisms.