Open AccessExpression and regulation of 6‐phosphofructo‐2‐kinase/fructose‐2,6‐
bisphosphatase isozymes in white adipose tissue
Author(s) -
Bruni Paola,
Vandoolaeghe Pascale,
Rousseau Guy G.,
Hue Louis,
Rider Mark H.
Publication year - 1999
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.1999.00104.x
Subject(s) - isozyme , white adipose tissue , adipose tissue , white (mutation) , fructose , phosphofructokinase 2 , kinase , biology , biochemistry , enzyme , microbiology and biotechnology , gene
The aim of this work was to identify the 6‐phosphofructo‐2‐kinase/fructose‐2,6‐bisphosphatase (PFK‐2/FBPase‐2) isozyme(s) present in white adipose tissue. Ion‐exchange chromatography of PFK‐2 from rat epididymal fat pads yielded an elution pattern compatible with the presence of both the L (liver) and M (muscle) isozymes. This was consistent with a study of the phosphorylation of the purified adipose tissue enzyme by cAMP‐dependent protein kinase, by specific labelling of the preparation with [2‐ 32 P]fructose 2,6‐bisphosphate and by reaction with antibodies. Characterization of the PFK‐2/FBPase‐2 mRNAs showed that mature adipocytes express the mRNA that codes for the L isozyme and the two mRNAs that code for the M isozyme. Preadipocytes expressed mRNA that codes for the M isozyme. Incubation of rat epididymal fat pads with adrenaline stimulated glycolysis but decreased fructose 2,6‐bisphosphate concentrations without significant inactivation of PFK‐2. These results support previous findings showing that fructose 2,6‐bisphosphate is not involved in the adrenaline‐induced stimulation of glycolysis in white adipose tissue.