Multiple forms of 6-phosphofructo-2-kinase/fructose-2, 6
-bisphosphatase are expressed in perinatal rat liver.
Casado, Marta, Lisardo Bosc[acute]a, and Paloma Mart[acute]in-Sanz.
Instituto de Bioqu[acute]imica (CSIC-UCM). Facultad de Farmacia,
28040 Madrid. Spain
APStracts 2:0191E, 1995.
Fetal rat liver expresses a 6-phosphofructo-2-kinase/fructose-2,6
-bisphosphatase (PFK-2/FBPase-2) form that differs from the adult
liver enzyme in the inhibition by phosphorylation by the cyclic AMP
-dependent protein kinase, and in the recognition by an antibody
specific for the amino-terminal domain of the adult liver enzyme.
Northern blot analysis shows that fetal hepatocytes contains a
species of mRNA, which is 2.2 Kb in size and that exhibits the
maximal levels after delivery. PFK-2/FBPase-2 mRNA analysis using a
sensitive RNase protection assay reveals the presence of nearly
similar amounts of adult liver-specific and skeletal muscle-specific
mRNA in fetal liver and hepatocytes during the last days of
gestation, as well as a 233 bp protected fragment present in fetal
liver. These results were confirmed by polymerase chain reaction
using specific oligonucleotide pairs. Primer extension of fetal liver
cDNA suggests the presence of two initiation sites of transcription.
Analysis of the adult liver PFK-2/FBPase-2 protein during the
perinatal transition using a specific antibody shows a marked
accumulation of this form immediately after birth
Received 5 June 1995; accepted in final form 1 September 1995.
APS Manuscript Number E256-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 September 1995.