Prosomatostatin processing in Neuro2A cells. Role of beta-turn structure in the vicinity of the Arg-Lys cleavage site

Détails

ID Serval
serval:BIB_3C52D57DE5DB
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Prosomatostatin processing in Neuro2A cells. Role of beta-turn structure in the vicinity of the Arg-Lys cleavage site
Périodique
European Journal of Biochemistry
Auteur⸱e⸱s
Brakch  N., Boileau  G., Simonetti  M., Nault  C., Joseph-Bravo  P., Rholam  M., Cohen  P.
ISSN
0014-2956 (Print)
Statut éditorial
Publié
Date de publication
08/1993
Volume
216
Numéro
1
Pages
39-47
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Aug 15
Résumé
Proline residues located near the processing sites of human prosomatostatin were previously shown to be important for cleavage of the precursor into somatostatin 28 and somatostatin 14 [Gomez, S., Boileau, G., Zollinger, L., Nault, C., Rholam, M. & Cohen, P. (1989) EMBO J. 8, 2911-2916]. In this study, site-directed and regional mutagenesis of the human prosomatostatin cDNA coupled with analysis by circular-dichroism and Fourier-transform-infrared spectroscopies of the native and mutated peptide sequences were used to elucidate the role of proline in proteolytic processing. Glycine was substituted for proline a position -5 and the beta-turn-promoting sequence Pro-Arg-Glu-Arg, located near the somatostatin-14 cleavage site and predicted to form a beta-turn structure, was replaced by Ser-Ser-Asn-Arg or Tyr-Lys-Gly-Arg, which have been shown by X-ray diffraction to form beta turns in other proteins. Analysis of the prosomatostatin-derived peptides produced by expression of the mutated cDNA species in Neuro2A cells indicated that while Pro-5-->Ala abolished cleavage at the dibasic site, the formation of mutants [Gly-5] prosomatostatin, [Ser-5, Ser-4, Arg-3] prosomatostatin and [Tyr-5, Lys-4, Gly-3] prosomatostatin did not affect cleavage at the dibasic site but produced modifications in both the relative proportions of the generated hormones and in precursor processing efficiency. Moreover, spectroscopical analysis showed that whereas these substitutions did not modify the presence of a beta turn structure in the corresponding peptide sequences, replacement of Pro-5-->Ala resulted in a dramatic increase in alpha-helix accompanied by the significant decrease of other structures including beta turn. The data support the hypothesis that the proline residue near the processing site for somatostatin-14 production is an important structural feature for conferring on the cleavage domain the adequate conformation for accessibility to processing enzymes and permitting production of equivalent amounts of both hormones.
Mots-clé
Amino Acid Sequence Animals Arginine/*chemistry/metabolism Circular Dichroism Dna Fourier Analysis Humans Lysine/*chemistry/metabolism Mice Molecular Sequence Data Mutagenesis Mutagenesis, Site-Directed Proline/*chemistry/metabolism Protein Conformation Protein Precursors/*chemistry/genetics/metabolism *Protein Processing, Post-Translational Protein Structure, Secondary Somatostatin/*chemistry/genetics/metabolism Tumor Cells, Cultured
Pubmed
Web of science
Open Access
Oui
Création de la notice
28/01/2008 10:35
Dernière modification de la notice
20/08/2019 13:32
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