TY - JOUR
T1 - Regulatory R region of the CFTR chloride channel is a dynamic integrator of phospho-dependent intra- and intermolecular interactions
AU - Bozoky, Zoltan
AU - Krzeminski, Mickael
AU - Muhandiram, Ranjith
AU - Birtley, James R.
AU - Al-Zahrani, Ateeq
AU - Thomas, Philip J.
AU - Frizzell, Raymond A.
AU - Ford, Robert C.
AU - Forman-Kay, Julie D.
PY - 2013/11/19
Y1 - 2013/11/19
N2 - Intrinsically disordered proteins play crucial roles in regulatory processes and often function as protein interaction hubs. Here, we present a detailed characterization of a full-length disordered hub protein region involved in multiple dynamic complexes. We performed NMR, CD, and fluorescence binding studies on the nonphosphorylated and highly PKA-phosphorylated human cystic fibrosis transmembrane conductance regulator (CFTR) regulatory region, a ∼200-residue disordered segment involved in phosphorylation- dependent regulation of channel trafficking and gating. Our data provide evidence for dynamic, phosphorylation-dependent, multisite interactions of various segments of the regulatory region for its intra- and intermolecular partners, including the CFTR nucleotide binding domains 1 and 2, a 42-residue peptide from the C terminus of CFTR, the SLC26A3 sulphate transporter and antisigma factor antagonist (STAS) domain, and 14-3-3β. Because of its large number of binding partners, multivalent binding of individually weak sites facilitates rapid exchange between free and bound states to allow the regulatory region to engage with different partners and generate a graded or rheostat-like response to phosphorylation. Our results enrich the understanding of how disordered binding segments interact with multiple targets. We present structural models consistent with our data that illustrate this dynamic aspect of phospho-regulation of CFTR by the disordered regulatory region.
AB - Intrinsically disordered proteins play crucial roles in regulatory processes and often function as protein interaction hubs. Here, we present a detailed characterization of a full-length disordered hub protein region involved in multiple dynamic complexes. We performed NMR, CD, and fluorescence binding studies on the nonphosphorylated and highly PKA-phosphorylated human cystic fibrosis transmembrane conductance regulator (CFTR) regulatory region, a ∼200-residue disordered segment involved in phosphorylation- dependent regulation of channel trafficking and gating. Our data provide evidence for dynamic, phosphorylation-dependent, multisite interactions of various segments of the regulatory region for its intra- and intermolecular partners, including the CFTR nucleotide binding domains 1 and 2, a 42-residue peptide from the C terminus of CFTR, the SLC26A3 sulphate transporter and antisigma factor antagonist (STAS) domain, and 14-3-3β. Because of its large number of binding partners, multivalent binding of individually weak sites facilitates rapid exchange between free and bound states to allow the regulatory region to engage with different partners and generate a graded or rheostat-like response to phosphorylation. Our results enrich the understanding of how disordered binding segments interact with multiple targets. We present structural models consistent with our data that illustrate this dynamic aspect of phospho-regulation of CFTR by the disordered regulatory region.
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U2 - 10.1073/pnas.1315104110
DO - 10.1073/pnas.1315104110
M3 - Article
C2 - 24191035
AN - SCOPUS:84888085224
SN - 0027-8424
VL - 110
SP - E4427-E4436
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 47
ER -