PMID- 10085255
OWN - NLM
STAT- MEDLINE
DCOM- 19990719
LR  - 20220215
IS  - 0021-9533 (Print)
IS  - 0021-9533 (Linking)
VI  - 112 ( Pt 8)
DP  - 1999 Apr
TI  - Induction and nuclear translocation of hypoxia-inducible factor-1 (HIF-1): 
      heterodimerization with ARNT is not necessary for nuclear accumulation of 
      HIF-1alpha.
PG  - 1203-12
AB  - Hypoxia-inducible factor-1 (HIF-1) is a master regulator of mammalian oxygen 
      homeostasis. HIF-1 consists of two subunits, HIF-1alpha and the aryl hydrocarbon 
      receptor nuclear translocator (ARNT). Whereas hypoxia prevents proteasomal 
      degradation of HIF-1alpha, ARNT expression is thought to be oxygen-independent. 
      We and others previously showed that ARNT is indispensable for HIF-1 DNA-binding 
      and transactivation function. Here, we have used ARNT-mutant mouse hepatoma and 
      embryonic stem cells to examine the requirement of ARNT for accumulation and 
      nuclear translocation of HIF-1alpha in hypoxia. As shown by immunofluorescence, 
      HIF-1alpha accumulation in the nucleus of hypoxic cells was independent of the 
      presence of ARNT, suggesting that nuclear translocation is intrinsic to 
      HIF-1alpha. Co-immunoprecipitation of HIF-1alpha together with ARNT could be 
      performed in nuclear extracts but not in cytosolic fractions, implying that 
      formation of the HIF-1 complex occurs in the nucleus. A proteasome inhibitor and 
      a thiol-reducing agent could mimic hypoxia by inducing HIF-1alpha in the nucleus, 
      indicating that escape from proteolytic degradation is sufficient for 
      accumulation and nuclear translocation of HIF-1alpha. During biochemical 
      separation, both HIF-1alpha and ARNT tend to leak from the nuclei in the absence 
      of either subunit, suggesting that heterodimerization is required for stable 
      association within the nuclear compartment. Nuclear stabilization of the 
      heterodimer might also explain the hypoxically increased total cellular ARNT 
      levels observed in some of the cell lines examined.
FAU - Chilov, D
AU  - Chilov D
AD  - Institute of Physiology and Institute of Anatomy, University of Zurich-Irchel, 
      CH-8057 Zurich, Switzerland.
FAU - Camenisch, G
AU  - Camenisch G
FAU - Kvietikova, I
AU  - Kvietikova I
FAU - Ziegler, U
AU  - Ziegler U
FAU - Gassmann, M
AU  - Gassmann M
FAU - Wenger, R H
AU  - Wenger RH
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - J Cell Sci
JT  - Journal of cell science
JID - 0052457
RN  - 0 (ARNT protein, human)
RN  - 0 (Arnt protein, mouse)
RN  - 0 (DNA-Binding Proteins)
RN  - 0 (HIF1A protein, human)
RN  - 0 (Hif1a protein, mouse)
RN  - 0 (Hypoxia-Inducible Factor 1)
RN  - 0 (Hypoxia-Inducible Factor 1, alpha Subunit)
RN  - 0 (Nuclear Localization Signals)
RN  - 0 (Nuclear Proteins)
RN  - 0 (Receptors, Aryl Hydrocarbon)
RN  - 0 (Transcription Factors)
RN  - 138391-32-9 (Aryl Hydrocarbon Receptor Nuclear Translocator)
SB  - IM
MH  - Animals
MH  - Aryl Hydrocarbon Receptor Nuclear Translocator
MH  - Carcinoma, Hepatocellular/metabolism
MH  - Cell Nucleus/*metabolism
MH  - DNA-Binding Proteins/chemistry/*metabolism/physiology
MH  - Electrophoresis, Polyacrylamide Gel
MH  - Embryo, Mammalian/metabolism
MH  - Fibroblasts/metabolism
MH  - Fluorescent Antibody Technique, Indirect
MH  - HeLa Cells
MH  - Humans
MH  - Hypoxia
MH  - Hypoxia-Inducible Factor 1
MH  - Hypoxia-Inducible Factor 1, alpha Subunit
MH  - Immunoblotting
MH  - Mice
MH  - Nuclear Localization Signals/physiology
MH  - Nuclear Proteins/chemistry/*metabolism/physiology
MH  - Precipitin Tests
MH  - *Receptors, Aryl Hydrocarbon
MH  - Stem Cells
MH  - Transcription Factors/metabolism/*physiology
MH  - Tumor Cells, Cultured
EDAT- 1999/03/23 00:00
MHDA- 1999/03/23 00:01
CRDT- 1999/03/23 00:00
PHST- 1999/03/23 00:00 [pubmed]
PHST- 1999/03/23 00:01 [medline]
PHST- 1999/03/23 00:00 [entrez]
AID - 10.1242/jcs.112.8.1203 [doi]
PST - ppublish
SO  - J Cell Sci. 1999 Apr;112 ( Pt 8):1203-12. doi: 10.1242/jcs.112.8.1203.