PUBLICATION

Induction of Autophagy by Amino Acid Starvation in Fish Cells

Authors
Yabu, T., Imamura, S., Mizusawa, N., Touhata, K., and Yamashita, M.
ID
ZDB-PUB-120202-13
Date
2012
Source
Marine biotechnology (New York, N.Y.)   14(4): 491-501 (Journal)
Registered Authors
Yamashita, Michiaki
Keywords
amino acid starvation, autophagy, adaptation, microtubule-associated protein 1-light chain 3, zebrafish
MeSH Terms
  • Amino Acids/deficiency*
  • Animals
  • Autophagy*
  • Starvation/physiopathology*
  • Zebrafish/metabolism*
PubMed
22290406 Full text @ Mar. Biotechnol.
Abstract
Autophagy is well established as a starvation-induced process in yeast and mammalian cells and tissues. To elucidate the cellular mechanisms induced by starvation in fish, we characterized the induction of autophagy in cultured zebrafish cells under starvation conditions. As an autophagic marker protein, the microtubule-associated protein 1-light chain 3B protein (MAP1-LC3B) was cloned from the fish cells, and its expression and localization were characterized. In zebrafish embryonic (ZE) cells, posttranslational modifications produced two distinct forms of MAP1-LC3B, i.e., a cytosolic form and a membrane-bound form (types I and II, respectively). Immunofluorescence microscopy revealed fluorescently labeled autophagosomes in cells stably transfected with a green fluorescent protein (GFP)–MAP1-LC3B fusion protein and showed that this protein accumulated in punctate dots in a time-dependent manner in response to amino acid starvation. Starvation also induced the degradation of long-lived proteins. Treatment with 3-methyladenine and wortmannin, two class-III inhibitors of phosphoinositide 3-kinase (PI3K), repressed autophagy under starvation conditions, indicating that the PI3K class-III pathway regulates starvation-induced autophagy in fish.
Genes / Markers
Figures
Show all Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping