Protein labeling

Ilia A Droujinine, Amanda S Meyer, Dan Wang, Namrata D Udeshi, Yanhui Hu, David Rocco, Jill A McMahon, Rui Yang, JinJin Guo, Luye Mu, Dominique K Carey, Tanya Svinkina, Rebecca Zeng, Tess Branon, Areya Tabatabai, Justin A Bosch, John M Asara, Alice Y Ting, Steven A Carr, Andrew P McMahon, and Norbert Perrimon. 2021. “Proteomics of protein trafficking by in vivo tissue-specific labeling.” Nat Commun, 12, 1, Pp. 2382.Abstract
Conventional approaches to identify secreted factors that regulate homeostasis are limited in their abilities to identify the tissues/cells of origin and destination. We established a platform to identify secreted protein trafficking between organs using an engineered biotin ligase (BirA*G3) that biotinylates, promiscuously, proteins in a subcellular compartment of one tissue. Subsequently, biotinylated proteins are affinity-enriched and identified from distal organs using quantitative mass spectrometry. Applying this approach in Drosophila, we identify 51 muscle-secreted proteins from heads and 269 fat body-secreted proteins from legs/muscles, including CG2145 (human ortholog ENDOU) that binds directly to muscles and promotes activity. In addition, in mice, we identify 291 serum proteins secreted from conditional BirA*G3 embryo stem cell-derived teratomas, including low-abundance proteins with hormonal properties. Our findings indicate that the communication network of secreted proteins is vast. This approach has broad potential across different model systems to identify cell-specific secretomes and mediators of interorgan communication in health or disease.