Scaffold protein that connects plasma membrane proteins with members of the ezrin/moesin/radixin family and thereby helps to link them to the actin cytoskeleton and to regulate their surface expression. Necessary for cAMP-mediated phosphorylation and inhibition of SLC9A3 (PubMed:18829453). May also act as scaffold protein in the nucleus. Homodimer, and heterodimer with SLC9A3R1. Binds PDZK1. Found in a complex with EZR, PODXL and SLC9A3R2 (By similarity). Interacts (via the PDZ domains) with PODXL (via the C-terminal PDZ-binding motif DTHL); interaction is detected in glomerular epithelium cells (By similarity). Binds ADRB2, SLC9A3, P2RY1, P2YR2, SRY, RDX and LPAR2. Interacts with MCC and PODXL. Interacts with SGK1 and KCNJ1/ROMK1. Interacts (via the PDZ domains) with SLC26A6 isoform 4 and isoform 5. Localizes with EZR and PODXL at the apical cell membrane of glomerular epithelium cells and the sides of the food processes (By similarity). Nuclear, in a punctate pattern. Widely expressed. Extended N-terminus.