Diabetes, Vol 45, Issue 7 897-901, Copyright © 1996 by American Diabetes Association

ARTICLES

Human prohormone convertase 3 gene: exon-intron organization and molecular scanning for mutations in Japanese subjects with NIDDM

S Ohagi, H Sakaguchi, T Sanke, H Tatsuta, T Hanabusa and K Nanjo
First Department of Medicine, Wakayama University of Medical Science, Japan.

Proinsulin is converted to insulin by the concerted action of two sequence-specific subtilisin-like proteases termed prohormone convertase 2 (PC2) and prohormone convertase 3 (PC3). PC3 is a type I proinsulin-processing enzyme that initiates the sequential processing of proinsulin to insulin by cleaving the proinsulin molecule on the COOH-terminal side of the dibasic peptide, Arg31-Arg32, joining the B-chain and C-peptide. Thus, PC3 plays a key role in regulating insulin biosynthesis. Expressions of insulin and PC3, but not PC2, are coordinately regulated by glucose, consistent with the important role of PC3 in regulating proinsulin processing. NIDDM is associated with increased secretion of proinsulin and proinsulin-like molecules, suggesting that mutations in the PC3 gene may be involved in the development of this disorder. To examine this hypothesis, we have isolated and characterized the human PC3 gene and screened it for mutations in a group of Japanese subjects with NIDDM. The PC3 gene consists of 14 exons spanning more than 35 kb. The exon-intron organization of PC2 and PC3 genes are conserved, consistent with a common evolutionary origin for the prohormone convertase gene family. Single-strand conformational analysis and nucleotide sequencing of the entire coding region of the PC3 gene in 102 Japanese subjects with NIDDM revealed missense mutations in exons 2 (Arg/Gln53) and 14 (Gln/Glu638), neither of which was associated with NIDDM in this population. These data suggest that genetic variation in the PC3 gene is unlikely to be a major contributor to NIDDM susceptibility in Japanese.
CiteULike    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				L. J. Martin, A. G. Comuzzie, S. Dupont, N. Vionnet, C. Dina, S. Gallina, M. Houari, J. Blangero, and P. Froguel A Quantitative Trait Locus Influencing Type 2 Diabetes Susceptibility Maps to a Region on 5q in an Extended French Family Diabetes, December 1, 2002; 51(12): 3568 - 3572. [Abstract] [Full Text] [PDF]