Search bioRxiv⌕ Search

Biology subjects

Weller, B.

Publications and source records attributed to Weller, B..

4 recordsLinked to original sources

Systematic Discovery of Pathogen Effector Functions across Human Pathogens and Pathways

Pathogens deploy effector proteins to exploit host cell biology, and most pathogen open reading frames (ORFs) are rapidly evolving and lack functional annotation. We developed the eORFeome, a scalable functional genomics platform encompassing 3,835 effector ORFs from diverse viruses, bacteria, and parasites. High-throughput barcoded screens across NF{kappa}B, apoptosis, p53, cGAS-STING and MHC-I pathways revealed functions for hundreds of uncharacterized eORFs, unexpected new activities for known effectors, and distinct pathway-specific functions encoded by single ORFs. Illustrating the power of the approach, we identify HHV6A U14 as a p53 antagonist, HHV7 U21 as a dual-function STING antagonist and MHC-I antigen display inhibitor, and adenoviral 13.6K/i-leader protein as a de novo evolved TAP inhibitor that suppresses MHC-I display. These results establish a general framework for systematic effector annotation, uncover new mechanisms of host-pathogen interaction across kingdoms, and highlight pathogen effectors as a versatile toolkit for rewiring and probing human cellular pathways.

systems biology↗

KIPK and KIPK-LIKE1 suppress overbending during negative hypocotyl gravitropic growth

Plants use environmental cues, such as the direction of gravity or the direction, quantity and quality of light, to orientate organ and plant growth. During germination of angiosperm seeds in the soil, hypocotyl elongation is directed by negative gravitropism responses such that the seedling can reach the light for photosynthesis and autotrophic growth. Hypocotyl elongation in the soil, however, also requires mechanisms to efficiently grow around obstacles such as soil particles. Here, we identify KIPK (KINESIN-LIKE CALMODULIN-BINDING PROTEIN INTERACTING PROTEIN KINASE) and the paralogous KIPKL1 (KIPK-LIKE1) as genetically redundant regulators of hypocotyl bending, in that KIPK and KIPKL1 are required to efficiently align hypocotyl growth with the gravity vector after obstacle avoidance. At the same time, we find that the highly homologous KIPKL2 (KIPK-LIKE2) must be functionally distinct. We further find that KIPK, and likely also KIPKL1, phosphorylate BRXL2 (BREVIS RADIX LIKE2) and ARKs (ARMADILLO REPEAT KINESINs), that mutants of both KIPK phosphorylation substrates share the overbending phenotype with kipk kipkl1 mutants, and that KIPK and KIPKL1 act synergistically with the ARK-regulatory NEK6 (NIMA-RELATED PROTEIN KINASE6). We propose that KIPK and KIPKL1 regulate ARK kinesins and thereby cortical microtubules for efficient gravitropic hypocotyl bending.

plant biology↗

A gut meta-interactome map reveals modulation of human immunity by microbiome effectors

The molecular mechanisms by which the gut microbiome influences human health remain largely unknown. Pseudomonadota is the third most abundant phylum in normal gut microbiomes. Several pathogens in this phylum can inject so-called virulence effector proteins into host cells. We report the identification of intact type 3 secretion systems (T3SS) in 5 - 20% of commensal Pseudomonadota in normal human gut microbiomes. To understand their functions, we experimentally generated a high-quality protein-protein meta-interactome map consisting of 1,263 interactions between 289 bacterial effectors and 430 human proteins. Effector targets are enriched for metabolic and immune functions and for genetic variation of microbiome-influenced traits including autoimmune diseases. We demonstrate that effectors modulate NF-{kappa}B signaling, cytokine secretion, and adhesion molecule expression. Finally, effectors are enriched in metagenomes of Crohns disease, but not ulcerative colitis patients pointing toward complex contributions to the etiology of inflammatory bowel diseases. Our results suggest that effector-host protein interactions are an important regulatory layer by which the microbiome impacts human health.

microbiology↗

A map of direct SARS-CoV-2 protein interactions implicates specific human host processes

Key steps in viral propagation, immune suppression, and pathology are mediated by direct, binary, physical interactions between viral and host proteins. To understand the biology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we generated an unbiased systematic map of binary interactions between viral and host proteins, complementing previous co-complex association maps by conveying more direct mechanistic understanding and potentially enabling targeted disruption of direct interactions. To this end, we deployed two parallel strategies, identifying 205 virus-host and 27 intraviral binary interactions amongst 171 host and 19 viral proteins, and confirming high quality of these interactions via a calibrated orthogonal assay. Host proteins interacting with SARS-CoV-2 proteins are enriched in various cellular processes, including immune signaling and inflammation, protein ubiquitination, and membrane trafficking. Specific subnetworks provide new hypotheses related to viral modulation of host protein homeostasis and T-cell regulation. The binary virus-host protein interactions we identified can now be prioritized as targets for therapeutic intervention. More generally, we provide a resource of systematic maps describing which SARS-CoV-2 and human proteins interact directly.

systems biology↗