Proteomic profiling of the proteolytic events in the secretome of the transformed phenotype of melanocyte-derived cells using Terminal Amine Isotopic Labeling of Substrates

ABSTRACT: The comprehensive profiling of the repertoire of secreted proteins from cancer cells and/or tissue samples provides information on the signaling events that take place during oncogenesis as well as on the cross-talk between normal and tumoral cells. Moreover, the analysis of post translational modifications in secreted proteins may unravel biological circuits regulated by irreversible modifications such as, for example, proteolytic processing. In this context, we used Terminal Amine Isotopic Labeling of Substrates (TAILS) to perform a system-wide investigation on the N-terminome of the secretomes derived from a paired set of mouse melanocyte cell lines: Melan-a (a normal melanocyte) and Tm1 (its transformed phenotype). TAILS analysis allowed the profiling of co-translational modifications such as acetylated N-termini as well as proteolytic events in both secretomes. Although no significant difference has been found in the proportion of acetylated natural N-termini in both cell line secretomes, when evaluating amino acid identities at the scissile bond in internal peptides it was possible to detect significant differences, suggesting distinct proteolytic processes acting in the normal and tumoral secretomes. The mapping and annotation of cleavage sites in the tumoral secretome suggested functional roles of active proteases in central biological processes related to oncogenesis, such as the processing of growth factors, cleavage of extracellular matrix proteins and the shedding of ectopic domains from the cell surface, some of which may represent novel processed forms of the corresponding proteins. In the context of the tumor microenvironment, these results suggest important biological roles of proteolytic processing in murine melanoma secreted proteins.

INSTRUMENT(S): LTQ Orbitrap Velos

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Melanocyte, Cell Culture

DISEASE(S): Melanoma

SUBMITTER: Andre Zelanis  

LAB HEAD: André Zelanis

PROVIDER: PXD010169 | Pride | 2018-10-02

REPOSITORIES: Pride