Nanoscale Architecture Can Control Cellular Function.

Nanoscale protein clustering at the plasma membrane has emerged as a fundamental mechanism for organizing cellular signaling, yet how nanocluster size is actively regulated and whether architectural changes at this scale carry functional consequences remain poorly understood. Here, we used the prototypical membrane scaffold A-kinase anchoring protein 79 (AKAP79) as a model system to investigate these questions through an integrated approach combining homo-FRET imaging, super-resolution microscopy, computational modeling, and molecular biology techniques. We show that AKAP79 nanoclusters respond dynamically to signaling pathway activation through myosin-dependent mechanisms. Moreover, a modest increase in nanocluster diameter (∼28.9%) dramatically altered gene expression and cellular behavior. These findings reveal nanocluster size as an actively regulated modulator of signaling precision and functional fitness, with implications for the broad class of membrane proteins that organize into nanoscale assemblies.