title: The C-terminal region of S100A4 is important for its metastasis-inducing properties.
abstract: The EF-hand protein, S100A4, binds calcium ions and interacts specifically in vitro with protein targets. Elevated levels of S100A4 have been shown to produce a metastatic phenotype in independent models of breast cancer. The presence of S100A4 in the carcinoma cells of patients with different carcinomas is associated with reduced patient survival. In order to identify the region of the S100A4 molecule that is responsible for its metastasis-inducing properties, specific mutant S100A4 genes and proteins have been produced which contain targeted mutations to the two calcium-binding sites and a deletion of the last 15 amino-acid residues of the protein. The ability of the mutant proteins to bind to a potential specific target in vitro, nonmuscle myosin heavy chain, is correlated with their ability to cause motile, invasive and metastatic phenotypes. Mutation of the C-EF hand of S100A4 virtually abolished calcium binding, and motility/invasion in vitro, abolished interaction with a molecular target, and reduced metastasis induction by 2.5-3-fold. However, deletion of the last 15 amino acids of S100A4 reduced motility/invasion, target binding and metastasis-induction to similar extents as the C-EF-hand mutant, but reduced calcium binding by only 26%. The results suggest that the ability to interact with protein target(s) is important in S100A4-induced metastasis.
authors.affiliation: Cancer and Polio Research Fund Laboratories, Biosciences Building, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK.
authors.forename: Shu
authors.initials: S
authors.lastname: Zhang
authors.forename: Guozheng
authors.initials: G
authors.lastname: Wang
authors.forename: Dong
authors.initials: D
authors.lastname: Liu
authors.forename: Zhengzheng
authors.initials: Z
authors.lastname: Bao
authors.forename: David G
authors.initials: DG
authors.lastname: Fernig
authors.forename: Philip S
authors.initials: PS
authors.lastname: Rudland
authors.forename: Roger
authors.initials: R
authors.lastname: Barraclough
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D002465:Cell Movement; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009154:Mutation / Q000235:genetics; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis / Q000235:genetics; D009368:Neoplasm Transplantation; D024507:Nonmuscle Myosin Type IIA / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D051381:Rats; D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins; C499412:S100a4 protein, rat; D024507:Nonmuscle Myosin Type IIA; D002118:Calcium