bioRxiv Science⌕ Search

Biology subjects

Jenkins, K.

Publications and source records attributed to Jenkins, K..

4 recordsLinked to original sources

RfxCas13d Mediates Broad-Spectrum Suppression of Highly Pathogenic Avian Influenza

Highly pathogenic avian influenza viruses (HPAIVs) continue to cause substantial disease in birds and mammals, with repeated H5N1 spillovers highlighting the need for broadly protective antiviral strategies. Here we develop a programmable RNA-targeting antiviral platform based on RfxCas13d and evaluate its activity in avian cells. Screening of five Cas13 orthologs in chicken DF1 fibroblasts revealed RfxCas13d as the most potent and well tolerated effector. Virus-specific CRISPR RNAs (crRNAs) targeting conserved regions of positive- and negative-sense influenza RNA were tested against A/WSN/033[H1N1] and multiple HPAIV isolates, including a member of clade 2.3.4.4b H5N1. Targeting positive-sense RNA conferred superior influenza inhibitory activity and further enhanced by multiplexed crRNA expression. These findings establish RfxCas13d as a versatile RNA-guided antiviral platform and provide a route for broad-spectrum influenza control through conserved RNA targeting.

microbiology↗

Functional relocation of the maize chloroplast atpB gene to the nucleus restores photosynthetic competence to a gene-edited non-photosynthetic mutant

We present a novel approach to photosynthetic gene engineering in maize using a nuclear-encoded, chloroplast-targeted TALE-cytidine deaminase enzyme to create non-photosynthetic knockout mutants of the chloroplast rbcL gene. An off-target mutation in the adjacent atpB gene, encoding the {beta} subunit of ATP synthase, was consistently found in all edited lines, identified as pigment-deficient in tissue culture. These double mutants, carrying mutations in both genes, were purified to homoplasmy using unique leaf-base regeneration techniques. To test mutation complementation and identify the causal gene, nuclear transgenic lines expressing chloroplast-targeted RbcL and AtpB proteins were generated. The results show that nuclear expression of AtpB restores chlorophyll accumulation and supports wild-type growth in tissue culture.

plant biology↗

Gucy1α1 specifically marks kidney, heart, lung and liver fibroblasts

Fibrosis is a common outcome of numerous pathologies, including chronic kidney disease (CKD), a progressive renal function deterioration. Current approaches to target activated fibroblasts, key effector contributors to fibrotic tissue remodeling, lack specificity. Here, we report Gucy11 as a specific kidney fibroblast marker. Gucy11 levels significantly increased over the course of two clinically relevant murine CKD models and directly correlated with established fibrosis markers. Immunofluorescent (IF) imaging showed that Gucy11 comprehensively labelled cortical and medullary quiescent and activated fibroblasts in the control kidney and throughout injury progression, respectively. Unlike traditionally used markers platelet derived growth factor receptor beta (Pdgfr{beta}) and vimentin (Vim), Gucy11 did not overlap with off-target populations such as podocytes. Notably, Gucy11 labelled kidney fibroblasts in both male and female mice. Furthermore, we observed elevated GUCY11 expression in the human fibrotic kidney and lung. Studies in the murine models of cardiac and liver fibrosis revealed Gucy11 elevation in activated Pdgfr{beta}-, Vim- and alpha smooth muscle actin (Sma)-expressing fibroblasts paralleling injury progression and resolution. Overall, we demonstrate Gucy11 as an exclusive fibroblast marker in both sexes. Due to its multiorgan translational potential, GUCY11 might provide a novel promising strategy to specifically target and mechanistically examine fibroblasts.

molecular biology↗

Proteostasis collapse halts G1 progression and delimits replicative lifespan

Loss of proteostasis and cellular senescence are key hallmarks of cell aging, but whether they are subject to direct cause-effect relationships is not known. We show that most yeast cells arrest in G1 before death with low nuclear levels of cyclin Cln3, a key activator of Start extremely sensitive to chaperone status. Chaperone availability is seriously compromised in aged cells, and the G1 arrest coincides with massive aggregation of a metastable chaperone-activity reporter. A mathematical model integrating autocatalytic protein aggregation and a minimal Start network recapitulates empirical observations. As key predictions, G1-cyclin overexpression increases lifespan in a chaperone-dependent manner, and lifespan reduction by enforced protein aggregation is greatly alleviated by increased expression of specific chaperones or cyclin Cln3. Overall, our data indicate the crucial role of chaperone malfunction in setting lifespan in yeast cells, and configure a molecular pathway whereby proteostasis breakdown acts as a direct effector of cell senescence.

cell biology↗