Seven mutations in the human insulin gene linked to permanent neonatal/infancy-onset diabetes mellitus
J. Clin. Invest. Carlo Colombo, et al. 118:2148 doi:10.1172/JCI33777 [Go to this article.]

Figure 4
Misfolding and defective secretion of proinsulin mutants. 293T cells were transfected with empty vector or cDNAs encoding WT proinsulin or the following proinsulin mutants: L^B6P (P^B6); L^B11P (P^B11); L^B15Y^B16delinsH (H^B15,16); Y^A19X (X^A19); C^A6Y (Y^A6); R65L (L65); R65C (C65); and hAkita. (A) Transfected cells were metabolically labeled with ³⁵S–amino acids for 1 h and then further chased for 1 h. Cell lysates (C) and chase media (M) were immunoprecipitated with anti-insulin, and the samples were analyzed by nonreducing Tris-tricine-urea-SDS-PAGE. All proinsulin (Pro) disulfide isomers demonstrated different mobilities; the native form is the fast-migrating, secreted form obtained for WT proinsulin. (B) Recombinant proinsulin secreted for 16 h into serum-free medium was quantified by RIA.