3KZE

Crystal Structure of T-cell Lymphoma Invasion and Metastasis-1 PDZ in Complex With SSRKEYYA Peptide

Summary for 3KZE

• Entry DOI: 10.2210/pdb3kze/pdb
• Related: 3KZD
• Descriptor: T-lymphoma invasion and metastasis-inducing protein 1, Synthetic Peptide (3 entities in total)
• Functional Keywords: pdz, cell junction, cell adhesion, signaling protein, tiam1, guanine nucleotide exchange factor, guanine-nucleotide releasing factor, lipoprotein, myristate, phosphoprotein, polymorphism
• Biological source: Homo sapiens (human)
• Cellular location: Cell junction: Q13009
• Total number of polymer chains: 5
• Total formula weight: 32473.49

Authors

Shepherd, T.R.,Fuentes, E.J. (deposition date: 2009-12-08, release date: 2010-04-21, Last modification date: 2024-02-21)

Primary citation

Shepherd, T.R.,Klaus, S.M.,Liu, X.,Ramaswamy, S.,DeMali, K.A.,Fuentes, E.J.
The Tiam1 PDZ domain couples to Syndecan1 and promotes cell-matrix adhesion.
J.Mol.Biol., 398:730-746, 2010

PubMed Abstract: The T-cell lymphoma invasion and metastasis gene 1 (Tiam1) is a guanine exchange factor (GEF) for the Rho-family GTPase Rac1 that is crucial for the integrity of adherens junctions, tight junctions, and cell-matrix interactions. This GEF contains several protein-protein interaction domains, including a PDZ domain. Earlier studies identified a consensus PDZ-binding motif and a synthetic peptide capable of binding to the Tiam1 PDZ domain, but little is known about its ligand specificity and physiological role in cells. Here, we investigated the structure, specificity, and function of the Tiam1 PDZ domain. We determined the crystal structures of the Tiam1 PDZ domain free and in complex with a "model" peptide, which revealed the structural basis for ligand specificity. Protein database searches using the consensus PDZ-binding motif identified two eukaryotic cell adhesion proteins, Syndecan1 and Caspr4, as potential Tiam1 PDZ domain binding proteins. Equilibrium binding experiments confirmed that C-terminal peptides derived from Syndecan1 and Caspr4 bound the Tiam1 PDZ domain. NMR chemical shift perturbation experiments indicated that the Tiam1 PDZ/Syndecan1 and PDZ/Caspr4 complexes were structurally distinct and identified key residues likely to be responsible for ligand selectivity. Moreover, cell biological analysis established that Syndecan1 is a physiological binding partner of Tiam1 and that the PDZ domain has a function in cell-matrix adhesion and cell migration. Collectively, our data provide insight into the structure, specificity, and function of the Tiam1 PDZ domain. Importantly, our data report on a physiological role for the Tiam1 PDZ domain and establish a novel link between two previously unrelated signal transduction pathways, both of which are implicated in cancer.

PubMed: 20361982
DOI: 10.1016/j.jmb.2010.03.047

Experimental method

X-RAY DIFFRACTION (1.8 Å)