Proinsulin is a key Ag in type 1 diabetes, but the mechanisms regulating proinsulin immune tolerance are unknown. We have shown that preproinsulin-2 gene-deficient mice (proins-2(-/-)) are intolerant to proinsulin-2. In this study, we analyzed the mechanisms underlying T cell-mediated tolerance to proinsulin-2 in 129/Sv nonautoimmune mice. The expression of one proinsulin-2 allele, whatever its...

A plasmid containing human preproinsulin cDNA inserted into the endonuclease Pst I site of the ampicillinase gene of plasmid pBR322 was modified by excision of large portions of the ampicillinase-coding region to produce a variety of gene fusion combinations, many of which generated proteins detectable with antisera to insulin or human C peptide. In one case a perfect hybrid of the NH2-terminal...

Oligonucleotides designed to create hairpin structures were inserted upstream from the ATG initiator codon in several plasmids that encode preproinsulin, and the effects on translation were monitored in COS cells transfected by the vectors. Creation of a hairpin (delta G = -30 kcal/mol) that directly involves the ATG triplet at the start of the preproinsulin coding sequence does not reduce the ...

AMP-activated protein kinase (AMPK) has recently been implicated in the control of preproinsulin gene expression in pancreatic islet beta-cells [da Silva Xavier, Leclerc, Salt, Doiron, Hardie, Kahn and Rutter (2000) Proc. Natl. Acad. Sci. U.S.A. 97, 4023-4028]. Using pharmacological and molecular strategies to regulate AMPK activity in rat islets and clonal MIN6 beta-cells, we show here that th...

The organization of the insulin gene of the owl or night monkey (Aotus trivirgatus), a New World primate, is similar to that of the human gene. The sequences of these two genes and flanking regions possess 84.3% homology. An unusual feature of the owl monkey gene is the partial duplication and insertion of a portion of the A-chain coding sequence into the 3' untranslated region. The insulin gen...

Permanent neonatal diabetes mellitus is a rare form of insulin-requiring diabetes presenting within the first few weeks or months of life. Mutations in the insulin gene are the second most common cause of this form of diabetes. These mutations are located in critical regions of preproinsulin and are likely to prevent normal processing or folding of the preproinsulin/proinsulin molecule. To char...

The end-stage immunopathology of type 1 diabetes resulting in β-cell destruction appears to be strongly dominated by cytotoxic CD8 T lymphocytes (CD8 T cells). However, the mechanism of cytotoxicity used by autoreactive CD8 T cells in the human setting remains unknown. Using type 1 diabetes patient-derived preproinsulin-specific CD8 T-cell clones recognizing either an HLA-A2 (A*0201) or HLA-A24...

We have chosen a vertebrate model accessible during neurulation, the chick, for analysis of endogenous insulin signaling and its contribution to early embryonic cell survival. Unlike rodents, humans and chickens have a single preproinsulin gene, facilitating its prepancreatic expression characterization. We show that in vivo interference with embryonic insulin signaling using antisense oligonuc...

Per-Arnt-Sim (PAS) domain-containing kinases are common in prokaryotes, but a mammalian counterpart has only recently been described. Although the PAS domain of the mammalian PAS kinase (PASK) is closely related to the bacterial oxygen sensor FixL, it is unclear whether PASK activity is changed in mammalian cells in response to nutrients and might therefore contribute to signal transduction by ...