Format

Send to:

Choose Destination
See comment in PubMed Commons below
Mol Biol Cell. 2003 Feb;14(2):477-90.

Chemical genetic analysis of Apg1 reveals a non-kinase role in the induction of autophagy.

Author information

  • 1University of Michigan, Department of Molecular, Cellular and Developmental Biology, Ann Arbor 48109, USA.

Abstract

Macroautophagy is a catabolic membrane trafficking phenomenon that is observed in all eukaryotic cells in response to various stimuli, such as nitrogen starvation and challenge with specific hormones. In the yeast Saccharomyces cerevisiae, the induction of autophagy involves a direct signal transduction mechanism that affects membrane dynamics. In this system, the induction process modifies a constitutive trafficking pathway called the cytoplasm-to-vacuole targeting (Cvt) pathway, which transports the vacuolar hydrolase aminopeptidase I, from the formation of small Cvt vesicles to the formation of autophagosomes. Apg1 is one of the proteins required for the direct signal transduction cascade that modifies membrane dynamics. Although Apg1 is required for both the Cvt pathway and autophagy, we find that Apg1 kinase activity is required only for Cvt trafficking of aminopeptidase I but not for import via autophagy. In addition, the data support a novel role for Apg1 in nucleation of autophagosomes that is distinct from its catalytic kinase activity and imply a qualitative difference in the mechanism of autophagosome and Cvt vesicle formation.

PMID:
12589048
[PubMed - indexed for MEDLINE]
PMCID:
PMC149986
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk