PMID: 21131357
Authors:
Busam RD, Thorsell AG, Flores A, Hammarstrom M, Persson C, Obrink B, Hallberg BM
Title:
Structural basis of tumor suppressor in lung cancer 1 (TSLC1) binding to differentially expressed in adenocarcinoma of the lung (DAL-1/4.1B).
Journal:
J Biol Chem. 2010 Dec 3.
Abstract:
Perturbed cell-adhesion mechanisms are crucial for tumor invasion and metastasis. A cell-adhesion protein, Tumor Suppressor in Lung Cancer 1 (TSLC1), is inactivated in a majority of metastatic cancers. DAL-1 (differentially expressed in adenocarcinoma of the lung protein), another tumor suppressor, binds through its FERM domain to the TSLC1 C-terminal, 4.1 glycophorin C-like, cytoplasmic domain. However, the molecular basis for this interaction is unknown. Here, we describe the crystal structure of a complex between the DAL-1 FERM domain and a portion of the TSLC1 cytoplasmic domain. DAL-1 binds to TSLC1 through conserved residues in a well-defined hydrophobic pocket in the DAL-1 FERM domain's structural C-lobe. From the crystal structure, it is apparent that Tyr406 and Thr408 in the TSLC1 cytoplasmic domain form the most important interactions with DAL-1 and this was also confirmed by surface plasmon resonance studies. Our results refute earlier exon deletion experiments that indicated that glycophorin-C interacts with the alpha-lobe of 4.1 FERM domains.