Autophagy driven by a master regulator of hematopoiesis

Mol Cell Biol. 2012 Jan;32(1):226-39. doi: 10.1128/MCB.06166-11. Epub 2011 Oct 24.

Abstract

Developmental and homeostatic remodeling of cellular organelles is mediated by a complex process termed autophagy. The cohort of proteins that constitute the autophagy machinery functions in a multistep biochemical pathway. Though components of the autophagy machinery are broadly expressed, autophagy can occur in specialized cellular contexts, and mechanisms underlying cell-type-specific autophagy are poorly understood. We demonstrate that the master regulator of hematopoiesis, GATA-1, directly activates transcription of genes encoding the essential autophagy component microtubule-associated protein 1 light chain 3B (LC3B) and its homologs (MAP1LC3A, GABARAP, GABARAPL1, and GATE-16). In addition, GATA-1 directly activates genes involved in the biogenesis/function of lysosomes, which mediate autophagic protein turnover. We demonstrate that GATA-1 utilizes the forkhead protein FoxO3 to activate select autophagy genes. GATA-1-dependent LC3B induction is tightly coupled to accumulation of the active form of LC3B and autophagosomes, which mediate mitochondrial clearance as a critical step in erythropoiesis. These results illustrate a novel mechanism by which a master regulator of development establishes a genetic network to instigate cell-type-specific autophagy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy*
  • Cells, Cultured
  • Chromatin / genetics
  • Erythroblasts / cytology
  • Erythroblasts / metabolism
  • GATA1 Transcription Factor / genetics*
  • GATA1 Transcription Factor / metabolism
  • Gene Expression Regulation*
  • Genome-Wide Association Study
  • Hematopoiesis*
  • Humans
  • Lysosomes / metabolism
  • Mice

Substances

  • Chromatin
  • GATA1 Transcription Factor
  • GATA1 protein, human