Proteins rarely act in isolation, but rather function in multi-protein complexes. Accordingly, protein-protein interactomes are exceptionally valuable resources that provide deep mechanistic insights and generate myriad hypotheses. Current methods for interactome mapping, such as affinity purification mass-spectrometry (APMS), are extremely difficult to deploy in vivo, so little comprehensive interactome data yet exists for developing embryos and even less for specific tissues within embryos. This fact poses an especially acute problem for understanding highly dynamic processes in which post-transcriptional controls dominate, for example collective cell movements. Here, we will use tissue engaged in convergent extension, a crucial collective movement that elongates the axis of animal embryos, to test the efficacy of new label-free interactome mapping approaches. Successful completion of the project will therefore be significant both for developing broadly applicable new methods and also for providing systems-level insights into a disease- relevant, vertebrate collective cell movement.
This study centers on developing novel methods for systematically identifying protein-protein interactions in embryos. To explore the utility of the method, we focus our efforts on proteins involved in collective cell movements called convergent extension, which are governed by the planar cell polarity (or PCP) proteins. These experiments will be significant because defects in PCP proteins or convergent extension lead to ?neural tube defects? such as spina bifida and anencephaly, as well as congenital skeletal dysplasias.
