Different involvement for aldolase isoenzymes in kidney glucose metabolism: Aldolase B but not aldolase A colocalizes and forms a complex with FBPase

Abstract

The expression of aldolase A and B isoenzyme transcripts was confirmed by RT-PCR in rat kidney and their cell distribution was compared with characteristic enzymes of the gluconeogenic and glycolytic metabolic pathway: fructose-1,6-bisphosphatase (FBPase), phosphoenol pyruvate carboxykinase (PEPCK), and pyruvate kinase (PK). We detected aldolase A isoenzyme in the thin limb and collecting ducts of the medulla and in the distal tubules and glomerula of the cortex. The same pattern of distribution was found for PK, but not for aldolase B, PEPCK, and FBPase. In addition, co-localization studies confirmed that aldolase B, FBPase, and PEPCK are expressed in the same proximal cells. This segregated cell distribution of aldolase A and B with key glycolytic and gluconeogenic enzymes, respectively, suggests that these aldolase isoenzymes participate in different metabolic pathways. In order to test if FBPase interacts with aldolase B, FBPase was immobilized on agarose and subjected to binding experiments. The results show that only aldolase B is specifically bound to FBPase and that this interaction was specifically disrupted by 60 microM Fru-1,6-P2. These data indicate the presence of a modulated enzyme-enzyme interaction between FBPase and isoenzyme B. They affirm that in kidney, aldolase B specifically participates, along the gluconeogenic pathway and aldolase A in glycolysis.

NKCC2 Surface Expression in Mammalian Cells

“…Fructose 1,6,bisphosphate aldolase B is a key enzyme of the gluconeogenic glycolytic pathway (18). Mutations in the human aldolase B gene that result in diminished aldolase B activity cause the autosomal recessive disease, hereditary fructose intolerance (72,73).…”

“…In addition, to identify potential interacting partners of NKCC2, we screened a kidney cDNA expression library by the yeast two-hybrid assay using NKCC2 C terminus as bait. Among the positive identified clones, several matched the sequence of aldolase B. Aldolase B is a glycolytic enzyme that has specialized functions in fructose metabolism and gluconeogenesis (18,19). However, several studies reported that besides its principal role in the carbohydrate metabolism, aldolase could also exert other functions in the cell (20 -27).…”

Suppression of hypoxic cell death by APIP-induced sustained activation of AKT and ERK1/2

“…However, the C-terminal region of APIP rather than core domain is required for the activation of ERK1/2 during hypoxia (Figure 1e). For the explanations of how APIP induces the increased and long-lasting activities of AKT and ERK1/2, we examined aldolase activity of APIP, as APIP shows high homology with aldolase domains of many species (Yanez et al, 2005). Aldolase A is highly expressed during hypoxia.…”

Proteomic signature of reversine‐treated murine fibroblasts by 2‐D difference gel electrophoresis and MS: Possible associations with cell signalling networks

“…Both enzymes, however, are gluconeogenic intermediates and elevate the intracellular levels of ATP [61,62] supporting energy demand. In contrast the conversion of glyceraldehyde 3-phosphate to dihydroxy-acetone phosphate was reduced due to a decrement of triosephosphate isomerase (À1.54-fold).…”