Glucose utilization by tumor cells: a post-translational modification of mitochondrial hexokinase may play a regulatory role.
In Northern blot analysis of a series of tumor cell lines a single hexokinase mRNA species of 4.3 Kb was detected. Detailed examination of one such line, the rat AS-30D hepatoma, revealed that two mitochondrial species of hexokinase are present with a molecular mass of 115 and 107 KDa. The smaller of the two species is 4-fold more active than the larger. Only the larger, less active species is detected in the well differentiated H-35 rat hepatoma cell line which exhibits a lower glucose catabolic rate. These results suggest that a post-translational proteolytic event may play a central role in regulating the glucose utilization capacity of tumor cells by modulating the relative levels of high and low activity forms of hexokinase.
Paggi
M G
MG
Laboratory for Cell Metabolism and Pharmacokinetics, Regina Elena Cancer Institute, Rome, Italy.
Fanciulli
M
M
Del Carlo
C
C
Citro
G
G
Bruno
T
T
Floridi
A
A
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006593:Hexokinase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D008099:Liver / Q000201:enzymology*; D008114:Liver Neoplasms, Experimental / Q000201:enzymology*; D008297:Male; D008928:Mitochondria / Q000201:enzymology*; D008970:Molecular Weight; D011499:Protein Processing, Post-Translational; D012313:RNA / Q000302:isolation & purification / Q000378:metabolism; D012334:RNA, Neoplasm / Q000302:isolation & purification / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D007527:Isoenzymes; D012334:RNA, Neoplasm; D012313:RNA; D006593:Hexokinase; D005947:Glucose