Regulatory effects of galactose on galactose‐1‐phosphate uridyltransferase activity on human hepatoblastoma HepG2 cells

FEBS Letters

Davit-Spraul, A.¹  Soni, T.³  Heng Ng, K.²  Lemonnier, A.³  Pourci, M.L.³ 

[1] Laboratoire Central de Biochimie, Hôpital Bicêtre, 78, rue du Général Leclerc, 94275 Le Kremlin Bicêtre, France;INSERM U347, 80 rue du Général Leclerc, 94276 Le Kremlin-Bicêtre Cedex, France;Laboratoire de Biochimie Appliquée, Faculté de Pharmacie-Paris-XI, 92296 Chatenay-Malabry, France

关键词: Galactose-1-phosphate uridyltransferase;    HepG2 cell;   

DOI  :  10.1016/0014-5793(94)01133-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Galactose-1-phosphate uridyltransferase (GALT) deficiency results in galactosemia in man. We have studied the regulation of the GALT gene expression on the HepG2 cell line by growing the cells in glucose or galactose medium. No difference of K_m values was observed in glucose or galactose media but the V _max value with galactose was 50% higher than that with glucose. Also in galactose medium, an increased GALT specific activity was detected suggesting the production of more enzyme proteins. Yet, slot dot quantification of GALT mRNA revealed a decreased amount of these transcripts in cells cultured with galactose or inosine while Northern blot analysis revealed the normal 1.4 kb transcript in all culture media used. Finally, IEF gel analysis displayed different isozymic patterns for the GALT enzyme in cells grown in glucose, galactose or inosine media. With glucose-free media, the major band of GALT corresponds to that found in human liver. Altogether, these results suggest that the control of GALT gene expression in HepG2 cells is located at the post-transcriptional level and correlated to the growth rate of the cell.

【 授权许可】

Unknown