Write a 100-350 word essay about the enzyme human GFPT2. Provide information related to enzyme: i) function, ii) reaction pathways, ii) Location, and iv) diseases. In writing include these four subheadings

### Function
Human GFPT2, or glutamine-fructose-6-phosphate transaminase 2, is an enzyme that plays a key role in the hexosamine biosynthesis pathway (HBP). GFPT2 catalyzes the conversion of fructose-6-phosphate and glutamine into glucosamine-6-phosphate, a crucial step that determines the flow of metabolites into the pathway. This reaction is essential for producing UDP-N-acetylglucosamine (UDP-GlcNAc), a vital substrate used in glycosylation processes that modify proteins and lipids, influencing cellular signaling, protein stability, and metabolic regulation.

### Reaction Pathways
GFPT2 functions within the hexosamine biosynthesis pathway, a branch of glucose metabolism. After the production of glucosamine-6-phosphate by GFPT2, the metabolite is further processed into UDP-GlcNAc. This nucleotide sugar is then utilized in several glycosylation processes, including N-linked and O-linked glycosylation of proteins, and the synthesis of glycosaminoglycans. These modifications are critical for various cellular functions, including cell signaling, protein folding, and the maintenance of the extracellular matrix.

### Location
GFPT2 is primarily localized in the cytoplasm, where it interacts with glycolytic intermediates to regulate the entry of glucose metabolites into the hexosamine biosynthesis pathway. This cytoplasmic localization allows GFPT2 to efficiently catalyze the production of glucosamine-6-phosphate, ensuring the availability of UDP-GlcNAc for glycosylation processes throughout the cell.

### Diseases
Alterations in GFPT2 expression or function have been implicated in several diseases, particularly in cancer and metabolic disorders. Overexpression of GFPT2 has been observed in certain cancers, where it contributes to the enhanced glycosylation of proteins that promote tumor growth, survival, and metastasis. Additionally, dysregulation of the hexosamine biosynthesis pathway, where GFPT2 plays a critical role, has been linked to insulin resistance and type 2 diabetes. In these conditions, altered levels of UDP-GlcNAc affect insulin signaling and glucose metabolism, contributing to disease progression. Understanding the role of GFPT2 in these diseases may offer new avenues for therapeutic intervention targeting metabolic and glycosylation pathways.