DIXDC1 isoform, l-DIXDC1, is a novel filamentous actin-binding protein
详细信息 查看全文
- 作者：Xianshu Wang ; Li Zheng ; Zhaozhu Zeng ; Guangjin Zhou ; Jeremy Chien ; Chiping Qian ; George Vasmatzis ; Viji Shridhar ; Lin Chen and Wanguo Liu
- 关键词：DIXDC1 ; DIX domain ; Actin-binding protein ; Dvl ; Wnt signaling
- 刊名：Biochemical and Biophysical Research Communications
- 出版年：2006
- 出版时间：18 August 2006
- 年：2006
- 卷：347
- 期：1
- 页码：22-30
- 全文大小：567 K
文摘
Ccd1, a DIX domain containing Zebrafish protein involved in neural patterning, is a positive regulator of the Wnt signaling pathway. DIXDC1, the human homolog of Ccd1, has two predominant isoforms. The short form (s-DIXDC1) has a similar amino acid sequence compared with Ccd1, while the long form (l-DIXDC1) contains an extra N-terminal sequence containing a calponin-homology (CH) domain, suggesting additional interaction with actin that we have performed detailed analysis in this report. We show that mRNA expression of both DIXDC1 isoforms can be detected in various adult tissues by Northern blot analysis and is most abundant in cardiac and skeletal muscles. Both endogenous and ectopically expressed l-DIXDC1, but not s-DIXDC1, in cultured mammalian cells is localized to actin stress fibers at the filament ends in focal adhesion plaques. More importantly, l-DIXDC1 can directly bind to filamentous actin both in vitro and in vivo and the binding is mediated via a novel actin-binding domain (ABD) from amino acid 127 to 300. Thus, our data provide the first evidence that l-DIXDC1 may act as a novel branching component in the Wnt signaling pathway targeting both β-catenin–TCF complex for gene expression and cytoskeleton for regulating dynamics of actin filaments.