Abstract
Signaling proteins are composed of conserved protein interaction domains that serve as allosteric regulatory elements of enzymatic or binding activities. The ubiquitous, structurally conserved cyclic nucleotide binding (CNB) domain is found covalently linked to proteins with diverse folds that perform multiple biological functions. Given that the structures of cAMP-bound CNB domains in different proteins are very similar, it remains a challenge to determine how this domain allosterically regulates such diverse protein functions and folds. Instead of a structural perspective, we focus our attention on the energy landscapes underlying the CNB domains and their responses to cAMP binding. We show that optical tweezers is an ideal tool to investigate how cAMP binding coupled to interdomain interactions remodel the energy landscape of the regulatory subunit of protein kinase A (PKA), which harbors two CNB domains. We mechanically manipulate and probe the unfolding and refolding behavior of the CNB domains as isolated structures or selectively as part of the PKA regulatory subunit, and in the presence and absence of cAMP. Optical tweezers allows us to dissect the changes in the energy landscape associated with cAMP binding, and to examine the allosteric interdomain interactions triggered by the cyclic nucleotide. This single molecule approach can be used to study other modular, multidomain signaling proteins found in nature.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.