N-terminome profiling in HEK293T

ABSTRACT: Various forms of the protein, called proteoform, are generated by co- or post-translational modification, alternative splicing and alternative translation initiation site, resulting in interactions between ribosomes, mRNAs, tRNAs, and various enzymes. Here, we introduce a N-terminal peptide enrichment method (Nrich) using a negative selection on filter for the N-terminal peptides with two chemical reagents for labeling free amine and two endoproteases. We identified 6,525 acetylated (or partially acetylated) and 6,570 free protein N-termini from 5,727 proteins. The protein N-termini can be classified into nine groups, such as initial methionine removed or retained, non-terminal residue, signal/transit/pro-peptide removal, putative alternative translational initiation site (methionine removed or retained) and unknown processing, suggesting various proteoform in vivo. In addition, novel protein N-termini was identified in 5`-UTR sequence with pseudo start codon using customized database. Nrich can obtain information about protein stability, localization and function through the observation of finished N-terminal sequence of mature protein.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Hek-293t Cell

SUBMITTER: Jeonghun Yeom  

LAB HEAD: Cheolju Lee

PROVIDER: PXD005583 | Pride | 2017-08-17

REPOSITORIES: Pride