A comparative study of Pointed and Yan expression reveals new complexity to the transcriptional networks downstream of receptor tyrosine kinase signaling

作者：Lachance Jean Francois Boisclair; Pelaez Nicolas; Cassidy Justin J; Webber Jemma L; Rebay Ilaria^*; Carthew Richard W

来源：Developmental Biology, 2014, 385(2): 263-278.

DOI：10.1016/j.ydbio.2013.11.002

• Drosophila
• ETS transcription factor
• Embryo
• Imaginal discs
• EGFR signaling
• Gene regulation

The biochemical regulatory network downstream of receptor tyrosine kinase (RTK) signaling is controlled by two opposing ETS family members: the transcriptional activator Pointed (Pnt) and the transcriptional repressor Yan. A bistable switch model has been invoiced to explain how pathway activation can drive differentiation by shifting the system from a high-Yan/low-Pnt activity state to a low-Yan/high-Pnt activity state. Although the model explains yan and pnt loss-of-function phenotypes in several different cell types, how Yan and Pointed protein expression dynamics contribute to these and other developmental transitions remains poorly understood. Toward this goal we have used a functional GFP-tagged Pnt transgene (Pnt-GFP) to perform a comparative study of Yan and Pnt protein expression throughout Drosophila development. Consistent with the prevailing model of the Pnt-Yan network, we found numerous instances where Pnt-GFP and Yen adopt a mutually exclusive pattern of expression. However we also observed many examples of co-expression. While some co-expression occurred in cells where RTK signaling is presumed low, other co-expression occurred in cells with high RTK signaling. The instances of co-expressed Yan and Pnt-GFP in tissues with high RTK signaling cannot be explained by the current model, and thus they provide important contexts for future investigation of how context-specific differences in RTK signaling, network topology, or responsiveness to other signaling inputs, affect the transcriptional response.

• 出版日期2014-1-15
• 单位西北大学