Cell: CRISPR reveals a surprising discovery. Who is responsible for all the proteins?

Every cell in our body knows how to use phosphorylation to control the function and fate of proteins by adding the chemical marker phosphate group Although we have fully understood the phosphorylation process of most proteins that play a role in cells, the phosphorylation process of some extracellular proteins is still a mystery However, from wound healing to bone formation, human health and disease largely depend on proteins that play a role in extracellular Now researchers from the University of California, San Diego School of medicine have made a surprising discovery: the phosphorylation of more than 100 secreted proteins is controlled by an enzyme called fam20c The findings appear in the June 18 issue of the journal Cell Jack Dixon, Ph.D., a professor at the University of California San Diego School of medicine and senior author of the paper, said: "this work has opened up a new field of discovery and provided many new therapeutic targets for many aspects of cell biology and biomedical research, such as studying how cancer cells transfer." For example, a newborn with a fam20c mutation can develop a rare condition called Raine syndrome The loss of a fully functional fam20c can result in bone deformities, a condition that often results in the death of a newborn at birth On the other hand, many types of cancer are known to overproduce fam20 To further explore the role of fam20c in human health and disease, Dixon's team used CRISPR / cas9, a new popular gene editing technology, to delete the fam20c gene from liver, breast and bone cancer cells cultured in the laboratory They then collected cultures of these fam20c deficient and uncontrolled cancer cells and analyzed the proteins contained in each sample To their surprise, the researchers found that fam20c didn't just work on proteins involved in bone mineralogy In each cell type, 90% of the secretory proteins are phosphorylated by fam20c - a total of more than 100 different proteins Dixon's team also tested the ability of breast cancer cells to migrate and invade surrounding tissue with or without fam20c In a series of laboratory tests, they found that cell mobility without the enzyme was severely inhibited This means that in the case of real breast cancer, fam20c may help tumor metastasis Dr Sandra Wiley, co-author of the paper and researcher of Dixon laboratory, said: "in the past 60 years, protein phosphorylation research has revealed many important functions of protein phosphorylation in cells, so there is no reason to believe that the phosphorylation of extracellular proteins will be different We are now investigating the biological function and importance of each protein phosphorylated by fam20c "