Structural Features and Ligand Binding Properties of Tandem WW Domains from YAP and TAZ, Nuclear Effectors of the Hippo Pathway

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• 作者：Claire Webb ; Abhishek Upadhyay ; Francesca Giuntini ; Ian Eggleston ; Makoto Furutani-Seiki ; Rieko Ishima ; Stefan Bagby
• 刊名：Biochemistry
• 出版年：2011
• 出版时间：April 26, 2011
• 年：2011
• 卷：50
• 期：16
• 页码：3300-3309
• 全文大小：1066K
• 年卷期：v.50,no.16(April 26, 2011)
• ISSN：1520-4995

文摘

The paralogous multifunctional adaptor proteins YAP and TAZ are the nuclear effectors of the Hippo pathway, a central mechanism of organ size control and stem cell self-renewal. WW domains, mediators of protein鈭抪rotein interactions, are essential for YAP and TAZ function, enabling interactions with PPxY motifs of numerous partner proteins. YAP has single and double WW domain isoforms (YAP1 and YAP2) whereas only a single WW domain isoform of TAZ has been described to date. Here we identify the first example of a double WW domain isoform of TAZ. Using NMR, we have characterized conformational features and peptide binding of YAP and TAZ tandem WW domains (WW1鈭扺W2). The solution structure of YAP WW2 confirms that it has a canonical three-stranded antiparallel 尾-sheet WW domain fold. While chemical shift-based analysis indicates that the WW domains in the tandem WW pairs retain the characteristic WW domain fold, ¹⁵N relaxation data show that, within the respective WW pairs, YAP WW1 and both WW1 and WW2 of TAZ undergo conformational exchange. ¹⁵N relaxation data also indicate that the linker between the WW domains is flexible in both YAP and TAZ. Within both YAP and TAZ tandem WW pairs, WW1 and WW2 bind single PPxY-containing peptide ligand concurrently and noncooperatively with sub-mM affinity. YAP and TAZ WW1鈭扺W2 bind a dual PPxY-containing peptide with approximately 6-fold higher affinity. Our results indicate that both WW domains in YAP and TAZ are functional and capable of enhanced affinity binding to multi-PPxY partner proteins such as LATS1, ErbB4, and AMOT.