PMID- 1309605
OWN - NLM
STAT- MEDLINE
DCOM- 19920212
LR  - 20190501
IS  - 0027-8424 (Print)
IS  - 1091-6490 (Electronic)
IS  - 0027-8424 (Linking)
VI  - 89
IP  - 1
DP  - 1992 Jan 1
TI  - Targeting of hexokinase 1 to liver and hepatoma mitochondria.
PG  - 202-6
AB  - The proportion of hexokinase (HK; EC 2.7.1.1) isozyme 1 (HK1) that is bound to 
      the outer mitochondrial membrane is tissue specific and developmentally 
      regulated. HK activity is known to be markedly elevated in many cancer cells and 
      a significant fraction is mitochondrial bound. This study examined the role of 
      the 15-amino acid N-terminal domain of HK1 in binding to liver and hepatoma 
      mitochondria. A chimeric reporter construct, pCMVHKCAT, encoding this HK1 domain 
      coupled to the chloramphenicol acetyltransferase (CAT) gene was electroporated 
      into mouse Hepa 1-6 hepatoma cells. After digitonin treatment, cell fractions 
      were assayed for HK, lactate dehydrogenase, and CAT activities. Digitonin (75 
      micrograms/mg of protein) caused cytosolic leak but 70% of HK remained with the 
      pellet. HKCAT, like HK, remained predominantly with the pellet; CAT form the 
      control, pCMVCAT, remained mostly unbound. Binding of membrane-free cell extracts 
      to rat liver mitochondria in vitro showed 91% of the HKCAT bound, whereas only 
      12% of CAT bound. Specificity of HKCAT binding to mitochondria was demonstrated 
      by competition of HK1 for HKCAT binding sites on rat liver mitochondria as well 
      as by blockage of HKCAT binding by N,N'-dicyclohexylcarbodiimide, which 
      covalently binds to porin and blocks HK1 binding. Deletional mutant constructs of 
      HKCAT showed reduced binding with increasing deletion size. In summary, these 
      studies demonstrate that the 15-amino acid N-terminal domain of HK1 is necessary 
      and sufficient to confer mitochondrial binding properties to CAT and that there 
      is specificity for this binding to the mitochondria.
FAU - Gelb, B D
AU  - Gelb BD
AD  - Institute for Molecular Genetics, Baylor College of Medicine, Houston, TX 77030.
FAU - Adams, V
AU  - Adams V
FAU - Jones, S N
AU  - Jones SN
FAU - Griffin, L D
AU  - Griffin LD
FAU - MacGregor, G R
AU  - MacGregor GR
FAU - McCabe, E R
AU  - McCabe ER
LA  - eng
GR  - 1 F32 GM13063/GM/NIGMS NIH HHS/United States
GR  - 1 P30 HD24064/HD/NICHD NIH HHS/United States
GR  - 1 R01 HD22563/HD/NICHD NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Proc Natl Acad Sci U S A
JT  - Proceedings of the National Academy of Sciences of the United States of America
JID - 7505876
RN  - 0 (Bacterial Outer Membrane Proteins)
RN  - 0 (Porins)
RN  - 538-75-0 (Dicyclohexylcarbodiimide)
RN  - EC 2.7.1.1 (HK1 protein, mouse)
RN  - EC 2.7.1.1 (Hexokinase)
SB  - IM
MH  - Animals
MH  - Bacterial Outer Membrane Proteins/metabolism
MH  - Base Sequence
MH  - Cell Compartmentation/drug effects
MH  - DNA Mutational Analysis
MH  - Dicyclohexylcarbodiimide/pharmacology
MH  - Hexokinase/*genetics/metabolism
MH  - Liver Neoplasms, Experimental/*enzymology
MH  - Mice
MH  - Mitochondria, Liver/*enzymology
MH  - Molecular Sequence Data
MH  - Porins
MH  - Rats
MH  - Transfection
PMC - PMC48204
EDAT- 1992/01/01 00:00
MHDA- 1992/01/01 00:01
PMCR- 1992/07/01
CRDT- 1992/01/01 00:00
PHST- 1992/01/01 00:00 [pubmed]
PHST- 1992/01/01 00:01 [medline]
PHST- 1992/01/01 00:00 [entrez]
PHST- 1992/07/01 00:00 [pmc-release]
AID - 10.1073/pnas.89.1.202 [doi]
PST - ppublish
SO  - Proc Natl Acad Sci U S A. 1992 Jan 1;89(1):202-6. doi: 10.1073/pnas.89.1.202.