Search bioRxiv⌕ Search

Biology subjects

Landsberg, M. J.

Publications and source records attributed to Landsberg, M. J..

4 recordsLinked to original sources

Ancestral neuronal receptors are bacterial accessory toxins

Symbiosis and horizontal gene transfer events were crucial in the emergence of eukaryotic and multicellular life. A striking example is the acquisition of Teneurins, putative surface-exposed toxins in bacteria that function as cell adhesion receptors in metazoan neuronal development. Here, we demonstrate the evolutionary relationships between metazoan and bacterial Teneurins. We show that bacterial Teneurins are accessory proteins, that harbour diverse encapsulated toxins. They predominate in species with complex social behaviours, suggesting roles in both cell-to-cell competition and cooperation. Metazoan Teneurins are therefore repurposed bacterial toxins central to cell-to-cell communication in nervous systems. Their acquisition was a foundational event in the evolution of metazoans.

biochemistry↗

Molecular architecture of nucleosome remodeling and deacetylase sub-complexes by integrative structure determination

The Nucleosome Remodeling and Deacetylase (NuRD) complex is a chromatin-modifying assembly that regulates gene expression and DNA damage repair. Despite its importance, limited structural information describing the complete NuRD complex is available and a detailed understanding of its mechanism is therefore lacking. Drawing on information from SEC-MALLS, DIA-MS, XLMS, negative-stain EM, X-ray crystallography, NMR spectroscopy, secondary structure predictions and homology models, we applied Bayesian integrative structure determination to investigate the molecular architecture of three NuRD sub-complexes: MTA1-HDAC1-RBBP4 (MHR), MTA1N-HDAC1-MBD3GATAD2CC (MHM), and MTA1-HDAC1-RBBP4-MBD3-GATAD2A (NuDe). The integrative structures were corroborated by examining independent crosslinks, cryo-EM maps, biochemical assays, known cancer-associated mutations, and structure predictions from AlphaFold. The robustness of the models was assessed by jack-knifing. Localization of the full-length MBD3, which connects the deacetylase and chromatin remodeling modules in NuRD, has not previously been possible; our models indicate two different locations for MBD3, suggesting a mechanism by which MBD3 in the presence of GATAD2A asymmetrically bridges the two modules in NuRD. Further, our models uncovered three previously unrecognized subunit interfaces in NuDe: HDAC1C-MTA1BAH, MTA1BAH-MBD3MBD, and HDAC160-100-MBD3MBD. Our approach also allowed us to localize regions of unknown structure, such as HDAC1C and MBD3IDR, thereby resulting in the most complete and robustly cross-validated structural characterization of these NuRD sub-complexes so far.

biophysics↗

Complete protection by a single dose skin patch delivered SARS-CoV-2 spike vaccine

SARS-CoV-2 has infected over 160 million people and resulted in more than 3.3 million deaths, and we still face many challenges in the rollout of vaccines. Here, we use the high-density microarray patch to deliver a SARS-CoV-2 spike subunit vaccine directly to the skin. We show the vaccine, dry-coated on the patch is thermostable, and delivery of spike via HD-MAP induced greater cellular and antibody immune responses, with serum able to potently neutralize clinically relevant isolates including those from the B.1.1.7 and B.1.351 lineages. Finally, a single dose of HD-MAP-delivered spike provided complete protection from a lethal virus challenge, demonstrating that HD-MAP delivery of a SARS-CoV-2 vaccine is superior to traditional needle-and-syringe vaccination and has the potential to greatly impact the ongoing COVID-19 pandemic.

microbiology↗

The Nucleosome Remodeling and Deacetylase complex has an asymmetric, dynamic, and modular architecture

The Nucleosome Remodeling and Deacetylase (NuRD) complex is essential for development in complex animals but has been refractory to biochemical analysis. We present the first integrated analysis of the architecture of the native mammalian NuRD complex, combining quantitative mass spectrometry, covalent cross-linking, protein biochemistry and electron microscopy. NuRD is built around a 2:2:4 pseudo-symmetric deacetylase module comprising MTA, HDAC and RBBP subunits. This module interacts asymmetrically with a remodeling module comprising one copy each of MBD, GATAD2 and CHD subunits. The previously enigmatic GATAD2 controls the asymmetry of the complex and directly recruits the ATP-dependent CHD remodeler. Unexpectedly, the MTA-MBD interaction acts as a point of functional switching. The transcriptional regulator PWWP2A modulates NuRD assembly by competing directly with MBD for binding to the MTA-HDAC-RBBP subcomplex, forming a moonlighting PWWP2A-MTA-HDAC-RBBP complex that likely directs deacetylase activity to PWWP2A target sites. Taken together, our data describe the overall architecture of the intact NuRD complex and reveal aspects of its structural dynamics and functional plasticity.

biochemistry↗