3P-45（3C-O2-1620） PDF
細胞上清プロテオミクスが明らかにするメタロプロテアーゼの神経細胞分化過程における役割
Many membrane proteins are known to be subject to limited proteolysis at their juxtamembrane regions, which is called as ectodomain shedding. Ectodomain shedding membrane bounded-ligands results in activation of downstream signalings, while that of cell adhesion molecules causes loss of cell-cell contacts.
In order to know what kind of proteins are secreted during differentiation of neuronal cells in metalloprotease-dependent manners, secreted proteome (secretome) analyses of culture medium in which neuroblastoma N1E-115 were differentiated to neurons with or without GM6001, a broad-spectrum metalloprotease inhibitor, under non-serum condition were conducted. Because most of membrane-bounded proteins are known to have N-glycosylation, we included N-glycosylated peptides enrichment1,2) into our secretomics workflow.
Most of peptides declined in the presence of GM6001 were derived from cell adhesion molecules including Nectin-2, MUC18, and L1CAM. Surprisingly, GM6001-sensitive peptides also included those derived from protein tyrosine kinase receptors and multiple transmembrane proteins. These results indicate that differentiation of N1E-115 neuronal cells accompanies cell-autonomously activated release of more various kinds of proteins than it has been noted so far, in metalloprotease-dependent manners. We further showed that ADAM19 enhances cleavage of L1CAM in HEK293T, suggesting that secretome analyses shown here is a valuable method to screen a set of membrane-bounded proteins shed in some contexts.