TIGAR-TAT

TIGAR is a p53-inducible enzyme that catalyzes the hydrolysis of fructose-2-6 bisphosphate (F-2-6-BP) to fructose-6-phosphate and inorganic phosphate. F-2-6-BP is a powerful activator of 6-phosphofructose-1 kinase, the rate limiting enzyme of glycolysis. By lowering the intracellular level of F-2-6-BP, TIGAR expression leads to increased glucose processing via the pentose phosphate pathway, the major cellular source for NADPH. Protein transduction using TAT fusion proteins represents an alternative methodology for introducing transcription factors and other intracellular proteins into primary as well as transformed cells. Recombinant human TIGAR-TAT expressed in E. coli is a 36 kDa protein containing 284 amino-acid residues, including the 271 residues of full-length TIGAR fused to a 13-residue C-terminal peptide containing the TAT transduction domain (GGYGRKKRRQRRR) .