Molecular Cell：阻止癌细胞扩散的蛋白质Tes

生物谷

生物谷报道：英国科学家日前发现一种能阻止癌细胞在体内扩散的蛋白质，这一发现有助于开发新的癌症药物疗法。

英国广播公司２８日报道说，防止癌细胞扩散是癌症治疗中的难题，已有研究发现，一种叫“Ｍｅｎａ”的蛋白质大量存在于肿瘤中，并帮助癌细胞向全身扩散。英国癌症研究机构伦敦研究所的科学家发现一种叫“Ｔｅｓ”的蛋白质能阻止“Ｍｅｎａ”发挥作用。

科学家发现，“Ｔｅｓ”可将自己黏合在“Ｍｅｎａ”上，使“Ｍｅｎａ”不能和另一种特殊物质反应，从而导致“Ｍｅｎａ”失效，无法帮助癌细胞从肿瘤中扩散到别处。但是由于肿瘤中“Ｍｅｎａ”的量很大，所以通常“Ｔｅｓ”不能发挥阻止癌细胞扩散的关键作用。

参与此项研究的迈克尔·韦说，新研究成果将为癌症治疗研究开辟新路，未来如果人们能开发出一种含有大量“Ｔｅｓ”蛋白质成分的药物，就可以在人体内阻止“Ｍｅｎａ”发挥作用，从而防止癌细胞大量扩散。（援引新华网）

生物谷推荐英文原文：

Molecular Cell, Vol 28, 1071-1082, 28 December 2007

Short Article

Tes, a Specific Mena Interacting Partner, Breaks the Rules for EVH1 Binding

Batiste Boëda,1,6 David C. Briggs,2,3,6 Theresa Higgins,1 Boyan K. Garvalov,4 Andrew J. Fadden,2 Neil Q. McDonald,2,5 and Michael Way1,

1 Cell Motility Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London, WC2A 3PX, UK
2 Structural Biology Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London, WC2A 3PX, UK
3 Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, M13 9PT, UK
4 Max Planck Institute of Neurobiology, Am Klopferspitz 18, D-82152 Martinsried, Germany
5 School of Crystallography, Birkbeck College, London, WC1E 7HX, UK

Corresponding author
Michael Way
michael.way@cancer.org.uk

Summary

The intracellular targeting of Ena/VASP family members is achieved via the interaction of their EVH1 domain with FPPPP sequence motifs found in a variety of cytoskeletal proteins, including lamellipodin, vinculin, and zyxin. Here we show that the LIM3 domain of Tes, which lacks the FPPPP motif, binds to the EVH1 domain of Mena, but not to those of VASP or Evl. The structure of the LIM3:EVH1 complex reveals that Tes occludes the FPPPP-binding site and competes with FPPPP-containing proteins for EVH1 binding. Structure-based gain-of-function experiments define the molecular basis for the specificity of the Tes-Mena interaction. Consistent with in vitro observations, the LIM3 domain displaces Mena, but not VASP, from the leading edge and focal adhesions. It also regulates cell migration through a Mena-dependent mechanism. Our observations identify Tes as an atypical EVH1 binding partner and a regulator specific to a single Ena/VASP family member.

Figure S1. Tes Interacts Directly with the EVH1 Domain of Mena
(A) Immunoblot analysis of glutathione sepharose pull downs reveals that GST-EVH1 Mena resin retains GFP-tagged full length Tes (Tes) or its C-terminal half (C-Term, residues 230-421) but not the N-terminal half of the molecule (N-Term, residues 1-234) from HeLa cell extracts. The ponceau stain demonstrates all samples contained equivalent amounts of GST-EVH1 resin. The input (I) and bound (B) samples are indicated.
(B) Coomassie stained gel reveals that GST-EVH1 resin retains full length His-Tes but not His-Tes-C391A from a bacterial soluble fraction. The C391A mutation disrupts the structural integrity of the LIM3 domain and Mena binding (Garvalov et al, 2003).
(C) Immunoblot analysis of glutathione sepharose pull downs reveals that full length His-Tes is retained by a GST-EVH1 Mena resin but not by GST, GST-EVH2 Mena and GST-EVH1 VASP resins. The anti-GST immunoblot reveals that all samples contained similar amounts of each glutathione sepharose resin. In A-C, the protein on resin is
indicated with an asterisk.
(D) An example of the localization of Mena and vinculin in HeLa cells over expressing RFP-Tes or RFP-Tes-LIM3-4A.
(E) Quantification of Mena immunostaining at the focal adhesion of HeLa cells reveals that RFP-Tes but not RFP-Tes-LIM3-4A over expression significantly displaces Mena from focal adhesions. In each case 4x100 cells were analysed and the standard deviation is indicated. A standard student T-test gives a significance of p < 0.001 for the presence of Mena at focal adhesions between the two sets of data. Co-staining with anti-vinculin was used to assess the integrity of focal adhesions.