ATG23, a novel gene required for maturation of proaminopeptidase I, but not for autophagy

✍ Scribed by Khuyen Meiling-Wesse; Fotini Bratsika; Michael Thumm

• Book ID: 104443597
• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 352 KB
• Volume: 4
• Category: Article
• ISSN: 1567-1356
• DOI: 10.1016/s1567-1356(03)00207-1

✦ Synopsis

In rich media proaminopeptidase I is targeted to the vacuole via the Cvt pathway and during starvation via autophagy. We here identify Atg23 (Ylr431c), a protein of so far unknown function, as a novel component essential for proaminopeptidase I maturation under non-starvation conditions. Maturation of proaminopeptidase I takes place in starved atg23v cells. Selective vacuolar targeting of the autophagosomal marker GFP-Aut7 and the accumulation of autophagic bodies during starvation in the presence of phenylmethylsulfonyl fluoride suggest that autophagy occurs in atg23v cells but at a reduced rate. In atg23v cells mature vacuolar carboxypeptidase Y is present and accumulation of quinacrine suggests no significant defect in vacuolar acidification. Furthermore, growth of atg23v cells on nitrocellulose detects no significant secretion of carboxypeptidase Y.