GSBS Student Publications

Title

Clustering of Nck by a 12-residue Tir phosphopeptide is sufficient to trigger localized actin assembly

GSBS Program

Biochemistry & Molecular Pharmacology

Publication Date

2004-02-06

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Molecular Genetics and Microbiology

Document Type

Article

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

Enteropathogenic Escherichia coli (EPEC) translocates effector proteins into mammalian cells to promote reorganization of the cytoskeleton into filamentous actin pedestals. One effector, Tir, is a transmembrane receptor for the bacterial surface adhesin intimin, and intimin binding by the extracellular domain of Tir is required for actin assembly. The cytoplasmic NH2 terminus of Tir interacts with focal adhesion proteins, and its tyrosine-phosphorylated COOH terminus binds Nck, a host adaptor protein critical for pedestal formation. To define the minimal requirements for EPEC-mediated actin assembly, Tir derivatives were expressed in mammalian cells in the absence of all other EPEC components. Replacement of the NH2 terminus of Tir with a viral membrane-targeting sequence promoted efficient surface expression of a COOH-terminal Tir fragment. Artificial clustering of this fusion protein revealed that the COOH terminus of Tir, by itself, is sufficient to initiate a complete signaling cascade leading to pedestal formation. Consistent with this finding, clustering of Nck by a 12-residue Tir phosphopeptide triggered actin tail formation in Xenopus egg extracts.

DOI of Published Version

10.1083/jcb.200306032

Source

J Cell Biol. 2004 Feb 2;164(3):407-16. Link to article on publisher's site

Journal/Book/Conference Title

The Journal of cell biology

Related Resources

Link to article in PubMed

PubMed ID

14757753

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