Talk in iPoLS 2025 about Spatial Heterogeneity Alters the Dynamics of the Yeast Galactose Switch

Created on July 28, 2025

2025

Presentation
🕒 3:00 PM – 3:15 PM, July 28, 2025
📍 Auditorium – Beckman Institute for Advanced Science and Technology (Conference Venue)
👤 Tianyu Wu,…, Zan Luthey-Schulten
🏛️ NSF iPoLS Annual Meeting 2025 atUniversity of Illinois Urbana-Champaign, USA

We present the first 4D simulations of the galactose regulatory network in Saccharomyces cerevisiae using a hybrid computational framework that integrates reaction–diffusion master equations (RDME) with deterministic ordinary differential equations (ODEs). Leveraging the GPU-accelerated Lattice Microbes platform, we simulate stochastic gene regulation and deterministic metabolic reactions within a realistic cellular geometry derived from cryo-electron tomography (cryo-ET).

This high-resolution structural data enables spatial partitioning of cytosolic and ER-bound ribosomes, allowing for more accurate modeling of protein translation, including membrane-targeted proteins like the galactose transporter Gal2. Simulations show that exposure to 11 mM extracellular galactose induces rapid expression of 10,000–15,000 Gal2 transporters within 60 minutes. We also benchmark multi-GPU performance across spatial decompositions.

Our results highlight the impact of spatial heterogeneity on cellular decision-making and demonstrate the feasibility of whole-cell modeling in eukaryotic systems.