Visualizing real-time regulatory dynamics in active membrane transport

Protein transporters uphold critical gradients across biological membranes.

Complex regulatory machineries have evolved to ensure that the gradients exactly meet the requirements of particular transient microenvironments, membrane types, or organisms.

Even slight disturbances in this regulation can cause human disease, such as heart failure, epilepsy, and Wilson’s disease – but it is also a potential venue for fighting pathogenic bacteria and developments of new antibiotics.

The proposed research aims to understand the kinetic and structural basis of pH, lipid, and intradomain regulation of bacterial (Ca2+ and Zn2+) and human (Cu+) P-type ATPase transport.

We will use our developed combined time-resolved X-ray scattering/MD simulation methodology to track in real-time and resolve how ATP-dependent domain arrangements and kinetic distributions of transient intermediate states depend on regulatory conditions.

The experimentally-derived protein structures will provide a structural basis for bacterial pH regulation, lipid-protein communicative networks, and internal domain regulation of bacterial and human metal ion transport – and the structural information will be linked in time – which is out of scope for most other structural biology techniques.

Thus, the proposed 4-year project has potential to drastically enhance our understanding of membrane protein regulation.