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Wang, Yeming

Publications and source records attributed to Wang, Yeming.

5 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Design, synthesis and anticancer activities of halogenated Phenstatin analogs as microtubule destabilizing agent

A series of halogenated Phenstatin analogs were designed as microtubule destabilizing agent by docking study. It was synthesized within three steps starting from 2-chloro-5-iodobenzoic acid and substituted benzene. All the products were characterized by {sup 1}H NMR and {sup 13}C NMR spectral analysis, and the stereochemical structure was also confirmed by a single crystal X-ray diffraction crystallographic analysis. The microtubule destabilizing activities were evaluated in vitro with human liver cancer Huh-7 cell line and human lung cancer A549 cell line. Some of the HPAs were achieved IC{sub 50} about 5.0 μM against human liver cancer Huh-7 cells. .

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Engineering a conserved RNA regulatory protein repurposes its biological function in vivo

PUF (PUmilio/FBF) RNA-binding proteins recognize distinct elements. In C. elegans, PUF-8 binds to an 8-nt motif and restricts proliferation in the germline. Conversely, FBF-2 recognizes a 9-nt element and promotes mitosis. To understand how motif divergence relates to biological function, we first determined a crystal structure of PUF-8. Comparison of this structure to that of FBF-2 revealed a major difference in a central repeat. We devised a modified yeast 3-hybrid screen to identify mutations that confer recognition of an 8-nt element to FBF-2. We identified several such mutants and validated structurally and biochemically their binding to 8-nt RNA elements. Using genome engineering, we generated a mutant animal with a substitution in FBF-2 that confers preferential binding to the PUF-8 element. The mutant largely rescued overproliferation in animals that spontaneously generate tumors in the absence of puf-8. This work highlights the critical role of motif length in the specification of biological function.

Bhat, Vandita D.↗
DOE OSTI2012

Stacking interactions in PUF-RNA complexes

Stacking interactions between amino acids and bases are common in RNA-protein interactions. Many proteins that regulate mRNAs interact with single-stranded RNA elements in the 3' UTR (3'-untranslated region) of their targets. PUF proteins are exemplary. Here we focus on complexes formed between a Caenorhabditis elegans PUF protein, FBF, and its cognate RNAs. Stacking interactions are particularly prominent and involve every RNA base in the recognition element. To assess the contribution of stacking interactions to formation of the RNA-protein complex, we combine in vivo selection experiments with site-directed mutagenesis, biochemistry, and structural analysis. Our results reveal that the identities of stacking amino acids in FBF affect both the affinity and specificity of the RNA-protein interaction. Substitutions in amino acid side chains can restrict or broaden RNA specificity. We conclude that the identities of stacking residues are important in achieving the natural specificities of PUF proteins. Similarly, in PUF proteins engineered to bind new RNA sequences, the identity of stacking residues may contribute to 'target' versus 'off-target' interactions, and thus be an important consideration in the design of proteins with new specificities.

59 BASIC BIOLOGICAL SCIENCES↗