The central question we intend to investigate is how dynamic association and dissociation modulates the functional state of membrane proteins under the condition of conserving their molecular identity. We will address this question on two systems, I) molecular components central for ethylene perception in plants, which are located at the ER and Golgi membranes, and II) PlbF, a novel phospholipase A from P. aeruginosa suggested to be a virulence factor, which is anchored in the inner bacterial membrane and exposed to the periplasm. In both cases, (multi)membrane systems play a crucial role for spatial coordination of dynamic association and dissociation. By molecular simulation and modeling studies at an atomic level in close connection with experimental validation studies, we intend to provide insights on I) the role and transport of the copper cofactor for ethylene receptor biogenesis and ethylene perception in plants and II) the molecular mechanism of monomerization/dimerization-dependent PlbF activation. As for both systems either almost none or only static atomic-level information is available, it is mandatory to develop a conceptual framework of adequate computational approaches and high-content experimental platforms in the course of the investigations. The two systems are paradigmatic for addressing the central question that way, also with respect to other systems investigated within the CRC.