Biology subjects

Grady, C. J.

Publications and source records attributed to Grady, C. J..

4 recordsLinked to original sources

bioRxiv2023

A Novel Protein for the Bioremediation of Gadolinium Waste

Several hundreds of tons of gadolinium-based contrast agents (GBCAs) are being dumped into the environment every year. Although macrocyclic GBCAs exhibit superior stability compared to their linear counterparts, we have found that the structural integrity of chelates are susceptible to ultraviolet light, regardless of configuration. In this study, we present a synthetic protein termed GLamouR that binds and reports gadolinium in an intensiometric manner. We then explore the extraction of gadolinium from GBCA-spiked artificial urine samples and investigate if the low picomolar concentrations reported in gadolinium-contaminated water sources pose a barrier for bioremediation. Based on promising results, we anticipate GLamouR can be used for detecting and mining REEs beyond gadolinium as well and hope to expand the biological toolbox for such applications.

bioengineering↗

bioRxiv2022

Proposed three-phenylalanine motif involved in magnetoreception signaling of an Actinopterygii protein expressed in mammalian cells

Studies at the cellular and molecular level of magnetoreception - sensing and responding to magnetic fields - is a relatively new research area. As it appears that different mechanisms of magnetoreception in animals evolved from different origins, many questions about the mechanisms remain left open. Here we present new information regarding the Electromagnetic Perceptive Gene (EPG) from Kryptopterus vitreolus that may serve as part of the foundation to understanding and applying magnetoreception. Using HaloTag coupled with fluorescent ligands and phosphatidylinositol specific phospholipase C (PI-PLC) we show that EPG is associated to the membrane via glycosylphosphatidylinositol (GPI) anchor. EPGs function of increasing intracellular calcium was also used to generate an assay using GCaMP6m to observe the function of EPG and to compare its function with homologous proteins. It was also revealed that EPG relies on a motif of three phenylalanine residues in order to function - stably swapping these residues using site directed mutagenesis resulted in a loss of function in EPG. This information not only expands upon our current understanding of magnetoreception but may provide a foundation and template to continue characterizing and discovering more within the field. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/519643v1_ufig1.gif" ALT="Figure 1"> View larger version (58K): org.highwire.dtl.DTLVardef@19a4f54org.highwire.dtl.DTLVardef@1ce17b2org.highwire.dtl.DTLVardef@175b97borg.highwire.dtl.DTLVardef@1e45294_HPS_FORMAT_FIGEXP M_FIG C_FIG In BriefEPG is a magnetoreceptive GPI anchored protein. Critical to its function is a three-phenylalanine motif which allows EPG to sense and respond to EMF. When expressed in mammalian cell, an increase in intracellular calcium is observed using GCaMP6m. This work represents progress towards understanding magnetoreception for use in future technologies. HighlightsO_LIEPG is associated to the cell membrane via glycosylphosphatidylinositol anchoring C_LIO_LIIn mammalian cells, EPG increases intracellular calcium upon EMF stimulation C_LIO_LIHomologs of EPG from the uPAR/Ly6 family show different responses to EMF C_LIO_LIA three-phenylalanine motif in EPG is critical to its magnetoreceptive ability C_LI

molecular biology↗

bioRxiv2022

A putative design for electromagnetic activation of split proteins for molecular and cellular manipulation

The ability to manipulate cellular function using an external stimulus is a powerful strategy for studying complex biological phenomena. One approach to modulate the function of the cellular environment is split proteins. In this method, a biologically active protein or an enzyme is fragmented so that it reassembles only upon a specific stimulus. While there are many tools available to induce these systems, nature has provided other mechanisms that can be utilized to expand the split protein toolbox. Here we show a novel method for reconstituting split proteins using magnetic stimulation. We have found that the Electromagnetic Perceptive Gene (EPG) changes conformation due to magnetic fields stimulation. By fusing split fragments of a certain protein to both termini of the EPG, the fragments can be reassembled into a functional protein under magnetic stimulation due to conformational change. We show this effect with three separate split proteins; NanoLuc, APEX2, and Herpes Simplex Virus Type-1 Thymidine Kinase. Our results show for the first time, that reconstitution of split proteins can be achieved only with magnetic fields. We anticipate that this study will be a starting point for future magnetically inducible split protein designs for cellular perturbation and manipulation. With this technology, we can help to expand the toolbox of the split protein platform and allow better elucidation of complex biological systems.

synthetic biology↗

bioRxiv2022

Identifying climatic drivers of hybridization in Heuchereae (Saxifragaceae)

Applications of molecular phylogenetic approaches have uncovered evidence of hybridization across numerous clades of life, yet the environmental factors responsible for driving opportunities for hybridization remain obscure. Verbal models implicating geographic range shifts that brought species together during the Pleistocene have often been invoked, but quantitative tests using paleoclimatic data are needed to validate these models. Here, we produce a phylogeny for Heuchereae, a clade of 15 genera and 83 species in Saxifragaceae, with complete sampling of recognized species, using 277 nuclear loci and nearly complete chloroplast genomes. We then employ an improved framework with a coalescent simulation approach to test and ultimately confirm previous hybridization hypotheses and identify one new intergeneric hybridization event. Focusing on the North American distribution of Heuchereae, we introduce and implement a newly developed approach to reconstruct potential past distributions for ancestral lineages across all species in the clade and across a paleoclimatic record extending from the late Pliocene. Time calibration based on both nuclear and chloroplast trees recovers a mid- to late-Pleistocene date for most inferred hybridization events, a timeframe concomitant with repeated geographic range restriction into overlapping refugia. Our results indicate an important role for past episodes of climate change, and the contrasting responses of species with differing ecological strategies, in generating novel patterns of range contact among plant communities and therefore new opportunities for hybridization.

evolutionary biology↗