Occurrence of the Crabtree effect in HeLa cells

✍ Scribed by Roberto F. Melo; Fabíola R. Stevan; Annibal P. Campello; Eva G. S. Carnieri; Maria Benigna Martinelli De Oliveira

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 152 KB
• Volume: 16
• Category: Article
• ISSN: 0263-6484
• DOI: 10.1002/(sici)1099-0844(199806)16:2<99::aid-cbf773>3.0.co;2-2

✦ Synopsis

The occurrence of a Crabtree effect in HeLa cells was detected. Some properties of pyruvate kinase (PK) were also evaluated. Hexose phosphate, triose-phosphate and phosphoenolpyruvate (PEP) significantly decreased the oxygen consumption of digitonin-permeabilized HeLa cells, which were oxidizing succinate. The Crabtree effect promoted by PEP was concentration-dependent and was lowered by an increase of ADP concentration, suggesting a participation of PK. The dependence of fructose-1,6-bisphosphate (FDP) by HeLa cell PK was observed. The PK of HeLa cells was inhibited by L-alanine only in the absence of FDP, while in the presence of the metabolite, an increase in the activity was observed. PK was also inhibited in the presence of L-histidine and L-leucine, while L-serine promoted activation. L-Cysteine and L-phenylalanine also inhibited the PK of HeLa cells. This, together with the sigmoidal character in relation to substrate concentration, suggests the presence of the K-type of PK in HeLa cells.