1H, 13C, and 15N backbone resonance assignment of the N-terminal 280 amino acids of human NHERF1 protein

Abstract NHERF1 (Na+/H+ exchanger regulatory factor-1) is a membrane-associated scaffold protein that links membrane receptors and channels to the actin cytoskeleton. It plays key roles in protein trafficking, signaling, and liver physiology. NHERF1 is a 358-residue long multidomain protein consisting of two PDZ domains, followed by a largely disordered region and a C-terminal ezrin-binding (EB) domain. In the liver, NHERF1 promotes the assembly of complexes containing ERM (ezrin-radixin-moesin) proteins, ICAM-1 (type I transmembrane protein intercellular adhesion molecule), and F-actin. Recent pull-down experiments have suggested that both PDZ1 and PDZ2 domains contribute to ICAM-1 binding. Characterization of this interaction by NMR chemical shift mapping requires a construct containing both PDZ domains. Although NMR studies have previously been reported for the individual PDZ1 and PDZ2 domains, as well as for the full-length NHERF1, no assignments were available for a construct containing only the PDZ domains. Full-length NHERF1 is not adequate for investigating PDZ-mediated interactions because its C-terminal EB domain interacts with PDZ2, causing resonance line broadening. In addition, the full-length 358-residue protein is expected to exhibit greater spectral overlap than a shorter construct. Here, we report the 1 H, 15 N, and 13 C backbone resonance assignments of a N-terminal 280 residue long NHERF1 construct encompassing both the PDZ1 and PDZ2 domains, thereby facilitating future studies of its interactions with ICAM-1 and other binding partners.