Research Highlights
Datta Lab
Spatial Self-organization of Confined Bacterial Suspensions
Bacteria often live in confined spaces (e.g., biological tissues, soil pores) where essential resources like oxygen are scarce. The population-scale implications of such confinement-induced chemical heterogeneities are poorly understood. Here, the Datta lab show that when motile bacteria are confined to small droplets, they spontaneously organize in space—forming a concentrated immotile core surrounded by a shell of motile cells. This self-organization emerges from a feedback loop: cells consume oxygen, creating gradients that alter cellular motility and distribution, which in turn reshapes these gradients. They establish a biophysical model that quantitatively describes how this phenomenon depends on system parameters and their findings could help understand bacterial ecological niches and inform approaches to engineer artificial active matter systems that self-organize through chemical feedback loops.
Nelson Lab
Spatially Aware Diffraction Mapping Enables Fully Autonomous MicroED
In the hands of experts, microcrystal electron diffraction (microED, a 3D ED method) is a powerful tool for structural chemistry and chemical discovery. To expand the accessibility and utility of microED, we introduce Reciprocal Eyes (REyes), an autonomous and intelligent platform (available for academic use) that combines diffraction-based particle selection with real-time data processing to deliver crystal structures without human intervention. REyes spatially maps diffraction signal and autonomously selects crystallites of interest, relying on lattice-quality metrics to acquire and index high-resolution data sets from diverse compounds. Tested on four different transmission electron microscopes (TEMs), it consistently yields preliminary ab initio structural solutions from single crystallites of materials, peptides, metal complexes, natural products (NPs), and proteins.
Reisman Lab
Enantioselective Synthesis of (+)-Auriculatol A
A total synthesis of the grayanane diterpenoid (+)-auriculatol A is reported. The synthesis features a convergent coupling strategy that joins two fragments by a vinylogous Mukaiyama–aldol-type reaction and then constructs the 7-membered ring by a Ni-catalyzed enolate alkenylation. Key findings include the development of a chemoselective Ni-catalyzed intramolecular 1,2-addition to access the bicyclo[3.2.1]octane fragment and the use of electron-deficient olefin supporting ligands as uniquely effective for the Ni-catalyzed enolate alkenylation.
Shan Lab
Principles of Cotranslational Mitochondrial Protein Import
Nearly all mitochondrial proteins are translated on cytosolic ribosomes. How these proteins are subsequently delivered to mitochondria remains poorly understood. Using selective ribosome profiling, we show that nearly 20% of mitochondrial proteins can be imported cotranslationally in human cells. Cotranslational import requires an N-terminal presequence on the nascent protein and contributes to localized translation at the mitochondrial surface. This pathway does not favor membrane proteins but instead prioritizes large, multi-domain, topologically complex proteins, whose import efficiency is enhanced when targeted cotranslationally. In contrast to the early onset of cotranslational protein targeting to the endoplasmic reticulum (ER), the presequence on mitochondrial proteins is inhibited from initiating targeting early during translation until a large globular domain emerges from the ribosome. Their findings reveal a multi-layered protein sorting strategy that controls the timing and specificity of mitochondrial protein targeting.
Wei Lab
Single-Cell Metabolic Imaging Reveals Glycogen-Driven Adaptations in Endothelial Cells
Diabetes mellitus (type II diabetes) affects more than 500 million people worldwide with cardiovascular complications remaining a major source of disability and mortality. A key contributor to these complications is endothelial cell dysfunction yet the metabolic changes driving this dysfunction have remained difficult to visualize in real time. In a collaborative effort with the Chen Lab at City of Hope and the TeSlaa Lab at UCLA, the Wei lab applied stimulated Raman scattering (SRS) microscopy to reveal how endothelial cells synthesize and store glycogen under diabetic conditions-- and how this stored glycogen reshapes their metabolic requirements during glucose deprivation. This study also marks the first live-cell visualization of lactate metabolism using Raman-based approaches, unlocking new opportunities to visualize small-molecule metabolites and capture the dynamic metabolic shifts that drive disease progression. These findings suggest that glycogen may play a regulatory role in modulating stress-responsive metabolic adaptations and may offer therapeutic opportunities to address diabetes-induced ED and related cardiometabolic diseases.