Insights into S100 Target Specificity Examined by a New Interaction between S100A11 and Annexin A2
详细信息 查看全文
- 作者：Anne C. Rintala-Dempsey ; Liliana Santamaria-Kisiel ; Yinyin Liao ; Gilles Lajoie ; Gary S. Shaw
- 刊名：Biochemistry
- 出版年：2006
- 出版时间：December 12, 2006
- 年：2006
- 卷：45
- 期：49
- 页码：14695 - 14705
- 全文大小：642K
- 年卷期：v.45,no.49(December 12, 2006)
- ISSN：1520-4995
文摘
S100 proteins are a group of EF-hand calcium-signaling proteins, many of which interactwith members of the calcium- and phospholipid-binding annexin family of proteins. This calcium-sensitiveinteraction enables two neighboring membrane surfaces, complexed to different annexin proteins, to bebrought into close proximity for membrane reorganization, using the S100 protein as a bridging molecule.S100A11 and S100A10 are two members of the S100 family found to interact with the N-termini ofannexins A1 and A2, respectively. Despite the high degree of structural similarity between these twocomplexes and the sequences of the peptides, earlier studies have shown that there is little or no cross-reactivity between these two S100s and the annexin peptides. In the current work the specificity and theaffinity of the interaction of the N-terminal sequences of annexins A1 and A2 with Ca2+-S100A11 wereinvestigated. Through the use of alanine-scanning peptide array experiments and NMR spectroscopy, anapproximate 5-fold tighter interaction was identified between Ca2+-S100A11 and annexin A2 (~3 
M)compared to annexin A1 (~15 M). Chemical shift mapping revealed that the binding site for annexinA2 on S100A11 was similar to that observed for the annexin A1 but with distinct differences involvingthe C-terminus of the annexin A2 peptide. In addition, kinetic measurements based on NMR titrationdata showed that annexin A2 binding to Ca2+-S100A11 occurs at a comparable rate (~120 s-1) to thatobserved for membrane fusion processes such as endo- and exocytosis.
M)compared to annexin A1 (~15 M). Chemical shift mapping revealed that the binding site for annexinA2 on S100A11 was similar to that observed for the annexin A1 but with distinct differences involvingthe C-terminus of the annexin A2 peptide. In addition, kinetic measurements based on NMR titrationdata showed that annexin A2 binding to Ca2+-S100A11 occurs at a comparable rate (~120 s-1) to thatobserved for membrane fusion processes such as endo- and exocytosis.