Our previous study demonstrated that WLIMla has dual roles in fiber elongation and secondary cell wall synthesis in upland cotton, and the protein acts either as an actin-binding protein or as a transcription factor. ...Our previous study demonstrated that WLIMla has dual roles in fiber elongation and secondary cell wall synthesis in upland cotton, and the protein acts either as an actin-binding protein or as a transcription factor. Because WLIMla consists of two different LIM domains, it is possible that these elements contribute differentially to the dual functions of the protein. In this study, we dissected the two LIM domains and characterized their biochemical functions. By using red fluorescent protein （RFP） fusion, co-sedimentation, and DNA binding methods, we found that the two domains of WLIM 1 a, domain 1 （D 1） and domain2 （D2）, possessed different biochemical properties. While D1 contributed primarily to the actin filament-bundling activity of WLIMla, D2 contributed to the DNA-binding activity of the protein; both D1 and D2 relied on a linker sequence for their ac- tivities. In addition, we found that WLIMla and its two LIM domains form dimers in vitro. These results may lead to a better understanding of the molecular mechanisms of dual functions of WLIMla during cotton fiber development.展开更多
基金the National Basic Research Priorities Program (U1303281)the China Postdoctoral Science Foundation
文摘Our previous study demonstrated that WLIMla has dual roles in fiber elongation and secondary cell wall synthesis in upland cotton, and the protein acts either as an actin-binding protein or as a transcription factor. Because WLIMla consists of two different LIM domains, it is possible that these elements contribute differentially to the dual functions of the protein. In this study, we dissected the two LIM domains and characterized their biochemical functions. By using red fluorescent protein （RFP） fusion, co-sedimentation, and DNA binding methods, we found that the two domains of WLIM 1 a, domain 1 （D 1） and domain2 （D2）, possessed different biochemical properties. While D1 contributed primarily to the actin filament-bundling activity of WLIMla, D2 contributed to the DNA-binding activity of the protein; both D1 and D2 relied on a linker sequence for their ac- tivities. In addition, we found that WLIMla and its two LIM domains form dimers in vitro. These results may lead to a better understanding of the molecular mechanisms of dual functions of WLIMla during cotton fiber development.
