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PC2 is a member of the eukaryotic family of subtilisin-like proteases, which is thought to participate in the processing of prohormones and proneuropeptides in neuroendocrine cells. PC2 is synthesized as a 69-kDa prepropolypeptide. The NH2-terminal signal sequence is removed during segregation within the endoplasmic reticulum, where glycosylation occurs to generate a 75-kDa propolypeptide. A combination of site-directed mutagenesis and a cell-free translation/translocation system from Xenopus eggs was used to investigate the processing of the pro-PC2 precursor. The 75-kDa polypeptide underwent slow cleavage after the sequence Arg-Lys-Lys-Arg84 to generate a 68-kDa mature enzyme. Cleavage was blocked when the tetrabasic sequence was deleted (PC2M3) or when the active site Asp142 was changed to Asn (PC2M4). This latter observation suggested that cleavage of the 75-kDa propolypeptide to the mature 68-kDa enzyme was autocatalytic. Incubation of the PC2M4 mutant with the wild type PC2 precursor resulted in cleavage of both the wild type polypeptide and the catalytically inactive PC2M4 mutant. This indicates that cleavage could occur through an intermolecular reaction. The results also demonstrate that the novel Xenopus egg extract translation/translocation system represents a powerful cell-free method for studying proteolytic processing of propolypeptides.
G Matthews, and
K I Shennan, and
A J Seal, and
N A Taylor, and
A Colman, and
K Docherty
February 1999,
Archives of biochemistry and biophysics,
G Matthews, and
K I Shennan, and
A J Seal, and
N A Taylor, and
A Colman, and
K Docherty
June 1992,
FEBS letters,
G Matthews, and
K I Shennan, and
A J Seal, and
N A Taylor, and
A Colman, and
K Docherty
March 2003,
Regulatory peptides,
G Matthews, and
K I Shennan, and
A J Seal, and
N A Taylor, and
A Colman, and
K Docherty
October 2000,
Journal of neurochemistry,
G Matthews, and
K I Shennan, and
A J Seal, and
N A Taylor, and
A Colman, and
K Docherty
August 1998,
Endocrine journal,
G Matthews, and
K I Shennan, and
A J Seal, and
N A Taylor, and
A Colman, and
K Docherty
August 1999,
Insect molecular biology,
G Matthews, and
K I Shennan, and
A J Seal, and
N A Taylor, and
A Colman, and
K Docherty
March 2002,
Biochimica et biophysica acta,
G Matthews, and
K I Shennan, and
A J Seal, and
N A Taylor, and
A Colman, and
K Docherty
May 1995,
Journal of neurochemistry,
G Matthews, and
K I Shennan, and
A J Seal, and
N A Taylor, and
A Colman, and
K Docherty
January 1996,
FEBS letters,
G Matthews, and
K I Shennan, and
A J Seal, and
N A Taylor, and
A Colman, and
K Docherty
June 1994,
Proceedings of the National Academy of Sciences of the United States of America,
