 |
PDBsum entry 2cgo
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Oxidoreductase
|
PDB id
|
|
|
|
2cgo
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Structural and mechanistic studies on the inhibition of the hypoxia-Inducible transcription factor hydroxylases by tricarboxylic acid cycle intermediates.
|
|
|
Authors
|
|
K.S.Hewitson,
B.M.Liénard,
M.A.Mcdonough,
I.J.Clifton,
D.Butler,
A.S.Soares,
N.J.Oldham,
L.A.Mcneill,
C.J.Schofield.
|
|
|
Ref.
|
|
J Biol Chem, 2007,
282,
3293-3301.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
In humans both the levels and activity of the alpha-subunit of the
hypoxia-inducible transcription factor (HIF-alpha) are regulated by its
post-translation hydroxylation as catalyzed by iron- and 2-oxoglutarate
(2OG)-dependent prolyl and asparaginyl hydroxylases (PHD1-3 and
factor-inhibiting HIF (FIH), respectively). One consequence of hypoxia is the
accumulation of tricarboxylic acid cycle intermediates (TCAIs). In vitro assays
were used to assess non-2OG TCAIs as inhibitors of purified PHD2 and FIH. Under
the assay conditions, no significant FIH inhibition was observed by the TCAIs or
pyruvate, but fumarate, succinate, and isocitrate inhibited PHD2. Mass
spectrometric analyses under nondenaturing conditions were used to investigate
the binding of TCAIs to PHD2 and supported the solution studies. X-ray crystal
structures of FIH in complex with Fe(II) and fumarate or succinate revealed
similar binding modes for each in the 2OG co-substrate binding site. The in
vitro results suggest that the cellular inhibition of PHD2, but probably not
FIH, by fumarate and succinate may play a role in the Warburg effect providing
that appropriate relative concentrations of the components are achieved under
physiological conditions.
|
|
|
|
|
|
|
|
Figure 1.
FIGURE 1. The reactions catalyzed by the HIF hydroxylases
(PHDs and FIH).
|
|
Figure 4.
FIGURE 4. Inhibition of t-PHD2 by the TCAIs (at 1 mM final
concentration). No inc refers to the assay without a
preincubation step; 1hrinc refers to a 1-h preincubation of
t-PHD2 with iron, buffer, and compound (where applicable), and
1hrinc + asc refers to a 1-h preincubation of t-PHD2 with iron,
buffer, and ascorbate.
|
|
|
|
|
|
The above figures are
reprinted
by permission from the ASBMB:
J Biol Chem
(2007,
282,
3293-3301)
copyright 2007.
|
|
|
|
|
|
|
