PMID- 23503782
OWN - NLM
STAT- MEDLINE
DCOM- 20140102
LR  - 20211021
IS  - 1432-2048 (Electronic)
IS  - 0032-0935 (Linking)
VI  - 237
IP  - 6
DP  - 2013 Jun
TI  - ATP produced by oxidative phosphorylation is channeled toward hexokinase bound to 
      mitochondrial porin (VDAC) in beetroots (Beta vulgaris).
PG  - 1571-83
LID - 10.1007/s00425-013-1866-4 [doi]
AB  - Mitochondrial porins or voltage-dependent anion channels (VDAC) are the main 
      route for solute transport through outer mitochondrial membranes (OMM). In 
      mammals, hexokinase (HK) binds to VDAC, which allows the channeling of ATP 
      synthesized by oxidative phosphorylation toward HK. In plants, although HK has 
      been found associated with OMM, evidence for an interaction with VDAC is scarce. 
      Thus, in this work, we studied the physical and functional interaction between 
      these proteins in beetroot mitochondria. To observe a physical interaction 
      between HK and VDAC, OMM presenting HK activity were prepared from purified 
      mitochondria. Protein complexes were solubilized from OMM with mild detergents 
      and separated by centrifugation in glycerol gradients. Both HK activity and 
      immunodetected VDAC were found in small (9S-13S) and large (>40S) complexes. OMM 
      proteins were also separated according to their hydropathy by serial phase 
      partitioning with Triton X-114. Most of HK activity was found in hydrophobic 
      fractions where VDAC was also present. These results indicated that HK could be 
      bound to VDAC in beetroot mitochondria. The functional interaction of HK with 
      VDAC was demonstrated by observing the effect of apyrase on HK-catalyzed glucose 
      phosphorylation in intact mitochondria. Apyrase, which hydrolyzes freely soluble 
      ATP, competed efficiently with hexokinase for ATP when it was produced outside 
      mitochondria (with PEP and pyruvate kinase), but not when it was produced inside 
      mitochondria by oxidative phosphorylation. These results suggest that HK closely 
      interacts with VDAC in beetroot mitochondria, and that this interaction allows 
      the channeling of respiratory ATP toward HK through VDAC.
FAU - Alcantar-Aguirre, Flor C
AU  - Alcantar-Aguirre FC
AD  - Departamento de Biotecnologia y Bioquimica, Cinvestav, Unidad Irapuato, Km 9.6 
      Libramiento Norte, CP 36821 Irapuato, Guanajuato, Mexico.
FAU - Chagolla, Alicia
AU  - Chagolla A
FAU - Tiessen, Axel
AU  - Tiessen A
FAU - Delano, John Paul
AU  - Delano JP
FAU - Gonzalez de la Vara, Luis Eugenio
AU  - Gonzalez de la Vara LE
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20130317
PL  - Germany
TA  - Planta
JT  - Planta
JID - 1250576
RN  - 0 (Mitochondrial Proteins)
RN  - 0 (Multiprotein Complexes)
RN  - 0 (Plant Proteins)
RN  - 0 (Voltage-Dependent Anion Channels)
RN  - 8L70Q75FXE (Adenosine Triphosphate)
RN  - EC 2.7.1.1 (Hexokinase)
SB  - IM
MH  - Adenosine Triphosphate/*biosynthesis
MH  - Amino Acid Sequence
MH  - Beta vulgaris/*enzymology
MH  - Hexokinase/chemistry/*metabolism
MH  - Hydrophobic and Hydrophilic Interactions
MH  - Mass Spectrometry
MH  - Mitochondria/*enzymology
MH  - Mitochondrial Membranes/enzymology
MH  - Mitochondrial Proteins/chemistry/metabolism
MH  - Molecular Sequence Data
MH  - Multiprotein Complexes/metabolism
MH  - *Oxidative Phosphorylation
MH  - Plant Proteins/chemistry/*metabolism
MH  - Protein Binding
MH  - Voltage-Dependent Anion Channels/*metabolism
EDAT- 2013/03/19 06:00
MHDA- 2014/01/03 06:00
CRDT- 2013/03/19 06:00
PHST- 2012/12/17 00:00 [received]
PHST- 2013/02/26 00:00 [accepted]
PHST- 2013/03/19 06:00 [entrez]
PHST- 2013/03/19 06:00 [pubmed]
PHST- 2014/01/03 06:00 [medline]
AID - 10.1007/s00425-013-1866-4 [doi]
PST - ppublish
SO  - Planta. 2013 Jun;237(6):1571-83. doi: 10.1007/s00425-013-1866-4. Epub 2013 Mar 
      17.