Please use this identifier to cite or link to this item:
Title: Ferric ions inhibit proteolytic processing of progastrin.
Austin Authors: Bramante, Gianni;Patel, Oneel;Shulkes, Arthur;Baldwin, Graham S
Affiliation: The University of Melbourne, Department of Surgery, Austin Health, Heidelberg, 3084 Victoria, Australia
Issue Date: 30-Dec-2010
Publication information: Biochemical and Biophysical Research Communications 2010; 404(4): 1083-7
Abstract: The gastrointestinal hormone gastrin is generated from an 80 amino acid precursor (progastrin) by cleavage after dibasic residues by prohormone convertase 1. Phosphorylation of Ser(75) has previously been suggested, on the basis of indirect evidence, to inhibit cleavage of progastrin after Arg(73)Arg(74). Gastrins bind two ferric ions with high affinity, and iron binding is essential for the biological activity of non-amidated gastrins in vitro and in vivo. This study directly investigated the effect of iron binding and of serine phosphorylation on the cleavage of synthetic progastrin-derived peptides. The affinity of synthetic progastrin(55-80) for ferric ions, and the rate of cleavage by prohormone convertase 1, were not affected by phosphorylation of Ser(75). In contrast, in the presence of ferric ions the rate of cleavage of both progastrin(55-80) and phosphoSer(75)progastrin(55-80) by prohormone convertase 1 was significantly reduced. Hence iron binding to progastrin may regulate processing and secretion in vivo, and regulation may be particularly important in diseases with altered iron homeostasis.
Gov't Doc #: 21195058
DOI: 10.1016/j.bbrc.2010.12.117
Journal: Biochemical and biophysical research communications
Type: Journal Article
Subjects: Amino Acid Sequence
Molecular Sequence Data
Proprotein Convertase 1.metabolism
Protein Precursors.chemistry.metabolism
Appears in Collections:Journal articles

Show full item record

Page view(s)

checked on Jan 30, 2023

Google ScholarTM


Items in AHRO are protected by copyright, with all rights reserved, unless otherwise indicated.