Yasinska IM, Gibbs BF, Lall GS, Sumbayev VV. The HIF-1 transcription complex is essential for translational control of myeloid hematopoietic cell function by maintaining mTOR phosphorylation.
Cell Mol Life Sci 2014;
71:699-710. [PMID:
23872956 PMCID:
PMC11113144 DOI:
10.1007/s00018-013-1421-2]
[Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 07/04/2013] [Accepted: 07/04/2013] [Indexed: 10/26/2022]
Abstract
Mammalian myeloid cells are crucial effectors of host innate immune defense. Normal and pathological responses of these cells require adaptation to signaling stress through the hypoxia-inducible factor 1 (HIF-1) transcription complex. Adapted cells activate the mammalian target of rapamycin (mTOR), via S2448 phosphorylation, which induces de novo translation of vital signaling proteins. However, the molecular mechanisms underlying this signaling dogma remain unclear. Here, we demonstrate for the first time that inactivation of HIF-1, by silencing its inducible alpha subunit, significantly decreases mTOR S2448 phosphorylation caused by ligand-dependent activation of human myeloid leukemia cells. This shows that HIF-1 is essential for the activation of mTOR and serves at a crucial juncture of myeloid cell function in both in vitro and in vivo systems.
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