Na⁺/H⁺ Exchanger Regulatory Factor-1 (NHERF-1): A PDZ-Domain Containing Protein Adaptor

Introduction

The Na⁺/H⁺ exchanger regulatory factor (NHERF-1 or EBP-50) is a 55 kD cytoplasmic protein adaptor that recruits a wide variety of cellular proteins. Many of the interacting proteins do so through the two tandem PDZ domains (protein-binding domains conserved in the mammalian synaptic protein PSD-95/DlgA/ZO-1) and the C-terminal ERM (ezrin, radixin, moesin) binding region.

NHERF-1 was first identified as an adaptor necessary for the function of the Na⁺/H⁺ exchanger isoform 3(NHE3) in renal apical cells¹. Since then it has been identified in cells of epithelial origin in several tissues such as gastrointestinal and lung. NHERF-1 has been shown to interact with a growing number of proteins including ion channels (ROMK, CFTR, TRPC4 and TRPC6), G-protein coupled receptors, (P2Y1 ) growth factor receptors (PDGFR), phospholipase C isoforms (PLCβ1, PLCβ2, PLCβ3), non-receptor protein tyrosine kinases (YAP65) and several cytoskeletal proteins that link membrane proteins to the underlying actin cytoskeleton². Recently it has been showed that NHERF-1 expression was elevated in breast tumors, when compared to the expression in adjacent normal tissue³.

New Antibody to NHERF-1

Our Anti-NHERF-1/EBP50 Antibody (#APZ-006) was developed against an epitope corresponding to residues 260-274 of rat NHERF-1 (Accession number Q9JJ19).

The epitope is located between the second PDZ domain and the C-terminal ERM binding region. The chosen rat epitope is highly homologous to the mouse (14 out of 15 residues) and human (13 out of 15 residues) NHERF-1 counterpart. The antibody is specific for NHERF-1 with no cross reactivity with the related protein NHERF-2.

References

1. Reczek, D. et al. (1997) J. Cell Biol. 139, 169.
2. Voltz, J.W. et al. (2001) Oncogene 20, 6309.
3. Stemmer-Rachamimov, A.O. et al. (2001) Am. J. Pathol. 158, 57.