Tyrosine O-sulfation promotes proteolytic processing of progastrin.

摘要: Tyrosine O-sulfation is a common post-translational modification of secretory and membrane proteins. The biological function sulfation known in only few proteins, where it appears to enhance protein-protein interactions. Based on sequences around sulfated tyrosines, consensus sequence for prediction target tyrosines has been proposed. However, some proteins are tyrosine at sites that deviate from the proposed consensus. Among these progastrin. It possible deviation explains incomplete characteristic bioactive gastrin peptides. In order test this hypothesis, we have performed site-directed mutagenesis gene followed by heterologous expression an endocrine cell line. results show substitution alanyl residue immediately N-terminal with acidic amino acid promotes Hence, study supports sulfation. Importantly, however, also reveal complete increases endoproteolytic maturation Thus, our suggests additional general significance.