Figure 5. TG2 activation results in increased UDP‐GlcNAc production.

• A
  Schematic view of the hexosamine biosynthesis pathway. Production of glucosamine‐6‐P by GFPT is the first and rate‐limiting step of the pathway that produces UDP‐GlcNAc. HK: hexokinase; G6PI: glucose‐6‐P isomerase; GFPT: glutamine:fructose‐6‐P amidotransferase; GNA: glucosamine‐6‐P N‐acetyltransferase; PGM3: phosphoglucomutase 3; UAP: UDP‐N‐acetylglucosamine pyrophosphorylase; OGT: O‐GlcNAc transferase OGA: O‐GlcNAcase; GlcNAc: N‐acetylglucosamine.
• B
  Endocervical epithelial cells were pre‐treated or not with 40 μM CP4d for 2 h before addition of the indicated concentration of ionomycin (or an equivalent volume of DMSO) and 0.5 μM BP. Six hours later, whole cell lysates were analyzed by Western blot. The membrane was first blotted with HRP‐conjugated streptavidin to detect TG2 activity and then extensively washed and probed with anti‐O‐GlcNAcylation antibody followed with HRP‐conjugated secondary antibodies. Last, the membrane was probed with anti‐actin as a loading control.
• C
  The same experimental procedure as described in (B) was applied to HeLa cells treated for 48 h prior to ionomycin treatment (8 μM) with siRNA control or directed against TG2.

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