Fig. 4. Negative regulation of TET3 by its CXXC domain.

a. Schematic representation of TET3, TET3-CXXC^mut and catalytically-inactive TET3-HxD^mut.

b. Increased protein expression of TET3-CXXC^mut relative to WT TET3 or TET3-HxD^mut (left panel), without a change in TET3 mRNA levels (right panel).

c. In-cell western assays confirm that TET3-CXXC^mut is expressed at higher levels than WT TET3 or TET3-HxD^mut.

d. WT TET3 and TET3-HxD^mut are mainly nuclear, whereas TET3-CXXC^mut is found in both cytoplasmic and nuclear fractions and is less effective at inducing PARP cleavage than WT TET3.

e. Cells expressing TET3-CXXC^mut show higher genomic 5hmC than cells expressing WT TET3 or TET3-HxD^mut (anti-CMS dot blot³).

f. Cxxc5 expression results in a decrease in protein levels of co-expressed Tet2 in HEK293T cells.

g. Potential intramolecular (auto-inhibitory) interaction between the linked CXXC and catalytic domains of TET3.