Comparative proteolytic processing of rat prosomatostatin by the convertases PC1, PC2, furin, PACE4 and PC5 in constitutive and regulated secretory pathways

N. Brakch, A. S. Galanopoulou, Y. C. Patel, G. Boileau, N. G. Seidah

Research output: Contribution to journalArticle

69 Scopus citations


Recombinant vaccinia virus vectors were used to coexpress each of the candidate prohormone convertases PC1, PC2, furin, PACE4 and PC5 with rat prosomatostatin (rProSOM) in the constitutive secreting cell line LoVo and in the endocrine corticotroph cell line AtT-20, which exhibits regulated secretion. Mammalian ProSOM is cleaved at a dibasic Arg-Lys↓ site to produce somatostatin-14 (S-14) and at a monobasic Gln-Arg↓ site to yield somatostatin-28 (S-28). The analysis of processed products by gel-permeation high performance liquid chromatography shows that in LoVo cells PC1, furin and PACE4 generate S-14, S-28 and a mixture of S-14 and S-28, respectively, while PC2 is unable to process ProSOM in these constitutive cells. In contrast, PC2 can generate S-14 in AtT-20 cells. The convertase PC5 is unable to process ProSOM in either cell line. These data suggest that PC2, PC1 and PACE4 are candidate S-14 convertases, while PACE4 and furin are candidate S-28 convertases.

Original languageEnglish (US)
Pages (from-to)143-146
Number of pages4
JournalFEBS Letters
Issue number2
Publication statusPublished - Apr 3 1995
Externally publishedYes



  • Coexpression
  • Constitutive and regulated cell
  • Convertase
  • Processing
  • Somatostatin
  • Vaccinia virus

ASJC Scopus subject areas

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology

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