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

FEBS Letters

Brakch, N.²  Galanopoulou, A.S.³  Patel, Y.C.³  Boileau, G.²  Seidah, N.G.¹ 

[1] J.A. DeSève Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, 110 Pine Avenue West, Montréal, Qué., H2W 1R7, Canada;Département de Biochimie, Faculté de Médecine, Université de Montréal, Montréal, Qué., H3C 3J7, Canada;McGill University, Departments of Medecine, Neurology and Neurosurgery, Royal Victoria Hospital and the Montreal Neurological Institute, Montréal, Qué., H3A 1A1, Canada

关键词: Somatostatin;    Convertase;    Processing;    Coexpression;    Vaccinia virus;    Constitutive and regulated cell;   

DOI  :  10.1016/0014-5793(95)00229-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown