Primary Information
BoMiProt ID	Bomi36
Protein Name	6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 3
Organism	Bos taurus
Uniprot ID	A0JN55
Milk Fraction	MFGM
Ref Sequence ID	NP_001071305.1
Aminoacid Length	514
Molecular Weight	58906
FASTA Sequence	Download
Gene Name	PFKFB3
Gene ID	407183
Protein Existence Status	Unreviewed: Experimental evidence at transcript level
Secondary Information
Protein Function	synthesis and degradatioil of fructose 2,6-bisphosphate (Fru-2,6-P2), which is an important regulator of glycolysis; atleast 3 isoforms in mammals - the liver (L), muscle (M) and heart (H) type isoenzymes [1].
Biochemical Properties	The three isoenzymes exist as homodimers; PFK/FBPase ratio is different for all 3 isozymes - 0.1-0.2 for type M and 80 for type H;Types L and H are substrates of the cyclic AMP-dependent; PKA treatment had no effect on vmax of PFK-2, its Km for MgATP, or its sensitivity towards inhibition by citrate; PKA treatment caused increased activity of PFK 2 at pH 7.0-7.5; Bovine heart FBPase-2 activity was maximal at pH 6.0; Treatment with PKA caused a small but insignificant increase in FBPase-2 activity measured at pH 5.5 and 6
Significance in milk	Involved in glucose metabolism; upregulated in early lactation period as compared to late pregnanacy
PTMs	phosphoryalted - phosphorylated in the presence of MgATP and cyclic AMP-dependent protein kinasc (PKA) or protein kinasc C (PKC); In rat liver PFK-YFBPase-2,phosphorylation site for PKA lies in the N-terminal domain at Ser-32, for bovine heart PFK-2/FBPase-2 the phosphorylation sites for PKA and PKC are in the C-terminal domain at Ser-466 and Thr-47S, respectively
Site(s) of PTM(s) N-glycosylation, O-glycosylation, Phosphorylation
Significance of PTMs	phosphorylation of the liver type leads to PFK-2 inactivation whereas phosphorylation of the Heart-type results in a small activation of PFK-2; Heart-Type PFK-2/FBPase-2 is also a substrate of protein kinase C (PKC), but phosphorylation has no effect on its enzyme activities
Linking IDs
Bibliography	1. Rider, M. H., van Damme, J., Vertommen, D., Michel, A., Vandekerckhove, J., & Hue, L. (1992). Evidence for new phosphorylation sites for protein kinase C and cyclic AMP-dependent protein kinase in bovine heart 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase. FEBS Letters, 310(2), 139–142. https://doi.org/10.1016/0014-5793(92)81315-d. 2. Jiang, L., Sørensen, P., Røntved, C., Vels, L., & Ingvartsen, K. L. (2008). Gene expression profiling of liver from dairy cows treated intra-mammary with lipopolysaccharide. BMC Genomics, 9. https://doi.org/10.1186/1471-2164-9-443. 3. Rider, M. H., Vandamme, J., Lebeau, E., Vertommen, D., Vidal, H., Rousseau, G. G., … Hue, L. (1992). The two forms of bovine heart 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase result from alternative splicing. The Biochemical Journal, 285 ( Pt 2), 405–411. https://doi.org/10.1042/bj2850405. 4. Finucane, K. A., McFadden, T. B., Bond, J. P., Kennelly, J. J., & Zhao, F.-Q. (2008). Onset of lactation in the bovine mammary gland: gene expression profiling indicates a strong inhibition of gene expression in cell proliferation. Functional & Integrative Genomics, 8(3), 251–264. https://doi.org/10.1007/s10142-008-0074-y.