Download MendeleyStructural basis of adenylyl cyclase 9 activation.
Qi, C., Lavriha, P., Mehta, V., Khanppnavar, B., Mohammed, I., Li, Y., Lazaratos, M., Schaefer, J.V., Dreier, B., Pluckthun, A., Bondar, A.N., Dessauer, C.W., Korkhov, V.M.(2022) Nat Commun 13: 1045-1045
- PubMed: 35210418
- DOI: https://doi.org/10.1038/s41467-022-28685-y
- Primary Citation of Related Structures:
7PD4, 7PD8, 7PDD, 7PDE, 7PDF, 7PDG, 7PDH - PubMed Abstract:
Adenylyl cyclase 9 (AC9) is a membrane-bound enzyme that converts ATP into cAMP. The enzyme is weakly activated by forskolin, fully activated by the G protein Gαs subunit and is autoinhibited by the AC9 C-terminus. Although our recent structural studies of the AC9-Gαs complex provided the framework for understanding AC9 autoinhibition, the conformational changes that AC9 undergoes in response to activator binding remains poorly understood. Here, we present the cryo-EM structures of AC9 in several distinct states: (i) AC9 bound to a nucleotide inhibitor MANT-GTP, (ii) bound to an artificial activator (DARPin C4) and MANT-GTP, (iii) bound to DARPin C4 and a nucleotide analogue ATPαS, (iv) bound to Gαs and MANT-GTP. The artificial activator DARPin C4 partially activates AC9 by binding at a site that overlaps with the Gαs binding site. Together with the previously observed occluded and forskolin-bound conformations, structural comparisons of AC9 in the four conformations described here show that secondary structure rearrangements in the region surrounding the forskolin binding site are essential for AC9 activation.
- Institute of Molecular Biology and Biophysics, ETH, Zurich, Switzerland.
Organizational Affiliation:
