Molecular cloning and tissue specific expression of fructose 6-phosphate,2-kinase:fructose 2,6-bisphosphatase of rat brain.

A cDNA clone (3591 base pairs) encoding an isozyme of Fructose 6-phosphate, 2-kinase:Fructose 2,6-bisphosphatase was isolated from a rat brain cDNA library. The 5' sequence of this clone (1241 base pairs) was identical to that of the heart type isozyme cDNA (except for 7 base pair mismatches), but the 3' nucleotide sequence (2024 base pairs) was completely different. Its deduced amino acid sequence showed that the enzyme lacked a regulatory domain which contained phosphorylation sites for protein kinase A and C. The results of Northern blotting and polymerase chain reaction demonstrated that the mRNA, 7.4 kilobases long, was expressed also in heart, testis, liver, and skeletal muscle.