TY - JOUR TI - Multi-state recognition pathway of the intrinsically disordered protein kinase inhibitor by protein kinase A AU - Olivieri, Cristina AU - Wang, Yingjie AU - Li, Geoffrey C AU - V S, Manu AU - Kim, Jonggul AU - Stultz, Benjamin R AU - Neibergall, Matthew AU - Porcelli, Fernando AU - Muretta, Joseph M AU - Thomas, David DT AU - Gao, Jiali AU - Blumenthal, Donald K AU - Taylor, Susan S AU - Veglia, Gianluigi A2 - Kay, Lewis E A2 - Faraldo-Gómez, José D A2 - Gardner, Kevin H VL - 9 PY - 2020 DA - 2020/04/27 SP - e55607 C1 - eLife 2020;9:e55607 DO - 10.7554/eLife.55607 UR - https://doi.org/10.7554/eLife.55607 AB - In the nucleus, the spatiotemporal regulation of the catalytic subunit of cAMP-dependent protein kinase A (PKA-C) is orchestrated by an intrinsically disordered protein kinase inhibitor, PKI, which recruits the CRM1/RanGTP nuclear exporting complex. How the PKA-C/PKI complex assembles and recognizes CRM1/RanGTP is not well understood. Using NMR, SAXS, fluorescence, metadynamics, and Markov model analysis, we determined the multi-state recognition pathway for PKI. After a fast binding step in which PKA-C selects PKI’s most competent conformations, PKI folds upon binding through a slow conformational rearrangement within the enzyme’s binding pocket. The high-affinity and pseudo-substrate regions of PKI become more structured and the transient interactions with the kinase augment the helical content of the nuclear export sequence, which is then poised to recruit the CRM1/RanGTP complex for nuclear translocation. The multistate binding mechanism featured by PKA-C/PKI complex represents a paradigm on how disordered, ancillary proteins (or protein domains) are able to operate multiple functions such as inhibiting the kinase while recruiting other regulatory proteins for nuclear export. KW - recombinant dna KW - protein expression KW - isotopic labeling JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -