The 4.1/ezrin/radixin/moesin domain of the DAL-1/Protein 4.1B tumour suppressor interacts with 14-3-3 proteins.
The Protein 4.1 family contains at least two members that function as tumour suppressors, the neurofibromatosis 2 gene product merlin and the recently identified differentially expressed in adenocarcinoma of the lung (DAL-1)/Protein 4.1B molecule. DAL-1/Protein 4.1B loss is observed in a variety of tumours, including breast and lung cancers as well as meningiomas. We have previously demonstrated that DAL-1/Protein 4.1B interacts with some but not all merlin-binding proteins, raising the possibility that DAL-1/Protein 4.1B associates with additional unique proteins specific to its function as a negative growth regulator. Using yeast two-hybrid interaction cloning, we identified three 14-3-3 isoforms, beta, gamma and eta, to be DAL-1/Protein 4.1B-binding proteins. These interactions were verified by using glutathione S-transferase affinity chromatography in vitro and co-immunoprecipitation in vivo. The interaction of 14-3-3 with DAL-1/Protein 4.1B was specific, as 14-3-3 did not bind to the related Protein 4.1 family members merlin, ezrin or radixin. The DAL-1/Protein 4.1B domain that mediates 14-3-3 binding was mapped to residues Pro(244) and Leu(280) within the 4.1/ezrin/radixin/moesin domain. The identification of this novel DAL-1/Protein 4.1B-interacting protein represents the first step towards elucidating its potentially unique mechanism of action.
Yu
Tingxi
T
David and Doreen Hermelin Laboratory of Molecular Oncogenetics, Department of Neurosurgery and Hermelin Brain Tumor Center, Henry Ford Hospital, E&R Bldg. Rm. 3096, 2799 W. Grand Blvd. Detroit, MI 48202, U.S.A.
Robb
Victoria A
VA
Singh
Vinita
V
Gutmann
David H
DH
Newsham
Irene F
IF
D048948:14-3-3 Proteins; D001798:Blood Proteins / Q000378:metabolism*; D001943:Breast Neoplasms; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000378:metabolism; D005260:Female; D006801:Humans; D008175:Lung Neoplasms; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008840:Microfilament Proteins / Q000378:metabolism*; D025581:Neurofibromin 2 / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism*; D011485:Protein Binding; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics / Q000378:metabolism*; D000099149:Ezrin
D048948:14-3-3 Proteins; D001798:Blood Proteins; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D008565:Membrane Proteins; D008840:Microfilament Proteins; D025581:Neurofibromin 2; D010750:Phosphoproteins; D020033:Protein Isoforms; D025521:Tumor Suppressor Proteins; D014446:Tyrosine 3-Monooxygenase; D000099149:Ezrin; C116887:EPB41L3 protein, human; C071058:moesin; C071776:radixin