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BP: Fachverband Biologische Physik
BP 14: Poster Session II
BP 14.59: Poster
Dienstag, 10. März 2026, 18:00–21:00, P2
Modeling the Clustering of Pma1 in the Yeast Plasma Membrane under Starvation — •Annemarie Quas1, Roland Wedlich-Söldner2, and Andreas Heuer1 — 1Institut für Physikalische Chemie, Universität Münster — 2Institut für Zelldynamik und Bildgebung, Universität Münster
Starvation of yeast cells leads to the internalization of most plasma membrane (PM) proteins via endocytosis, strongly reducing the overall protein content of the PM. However, the level of the H+-ATPase Pma1 is hardly affected by starvation. Instead, clustering of Pma1 is observed under these conditions. FF-EM images reveal 2D crystals composed of hexagonal units corresponding to Pma1 hexamers. Interestingly, deletion of Mrh1 blocks the clustering of Pma1. An interplay between the positively charged C-terminus of Mrh1 and the negatively charged phosphatidylserine (PS) is proposed, as Mrh1 is not required for clustering in the absence of PS. Because experimental insight into the mechanism of cluster formation is limited, we employ a coarse-grained Monte-Carlo model to investigate how interactions between Pma1 hexamers can drive large-scale organization. In our 2D model, Pma1 is represented as hexamers with attractive corner-to-corner interactions. By systematically varying particle density and interaction strength, we explore the system’s phase behavior and identify conditions under which extended cluster formation emerges. We analyze cluster sizes, time-dependent growth, and characteristic cluster shapes to gain mechanistic insight into how molecular interactions could stabilize the observed protein crystals.
Keywords: protein clustering; Pma1; yeast plasma membrane; modeling