Year: 2026
Type: preprint
Abstract: Diacylglycerols (DAGs) are central intermediates in lipid metabolism and signaling, yet their trafficking and persistence within lipid droplets (LDs) remain incompletely understood due to the lack of chemically stable, DAG-mimetic imaging tools. Here, we report the development of a family of solvatochromic fluorescent lipid analogs, termed DONDI, designed to probe DAG-associated dynamics at LDs. These probes are based on a 1,8-naphthalimide scaffold conjugated to modified aminoglycerol backbones bearing oleoyl chains to mimic native glycerolipids. Biophysical characterization and atomistic molecular dynamics simulations revealed probe-specific membrane insertion and hydrogen-bonding behaviors consistent with distinct lipid-mimetic properties. Live-cell imaging in NIH 3T3 fibroblasts demonstrated that DONDI probes were efficiently internalized and selectively accumulated within lipid droplets. Structure-function analysis identified DONDI-5 as the closest mimic of 1,2-diacylglycerol, displaying rapid uptake, strong LD enrichment, and prolonged intracellular retention without detectable relocalization to other cellular membranes. These properties enabled sustained visualization of LD-associated DAG pools over extended time scales. Collectively, this work establishes DONDI-5 as a chemically stable DAG-mimetic probe and provides direct experimental support that DAGs can be transported to and transiently stored within lipid droplets without prior conversion to triacylglycerols.
Authors: Christopher Gomez, Nicholas McInchak, Sarah Louis, Evan Heck, Haylee Mesa, Jonathan Meade, Qi Zhang, Maciej J. Stawikowski
Institution: Florida Atlantic University
Language: English
Subfield: Biochemistry
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7133188693